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LOREM IPSUM
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Public Lecture | 3D Printing for Perfect Metal Parts
Chris Tassone, 2019
To view more public lectures click HERE. Public Lecture | Discovering the Colors of Fossil Creatures
Nick Edwards, 2020
To view more public lectures click HERE. The accelerator lies in a tunnel 25 feet below the ground. The underground location keeps the temperature and humidity stable.
The 2006 Nobel Prize in Chemistry was awarded to Roger Kornberg for research carried out in part at SSRL. Kornberg revealed the process of transcription, through which DNA's genetic blueprint is read and used to direct the manufacture of proteins.
Time Lapse video of the construction of the MFX hutch
The MFX hutch has specialized equipment for determining the structures of proteins, which carry out many vital functions in living things. A goniometer holds a single microscopic protein crystal and positions it in front of the X-ray beam. A robotic arm holds the detector, and another robot switches out one sample for another. Eventually scientists will be able to mail their samples to LCLS and control MFX experiments remotely, even from another state or country.
With many common X-ray tools, the radiation damages the sample before scientists can get a clear image. However, the X-ray laser pulses at LCLS are so short that the photons outrun the damage, allowing scientists to capture information about the sample’s atomic structure in the instant before it’s destroyed. This is known as “diffract before destroy” and it’s especially useful for radiation-sensitive samples, like the protein complexes involved in photosynthesis.
SSRL X-Ray Crystallography Covid-19 Research
Stanford Synchrotron Radiation Lightsource (SSRL) is an extremely powerful X-ray source where researchers can study our world at the atomic and molecular level in many different fields, , such as biology, nanotechnology, energy production and new materials. During the pandemic, our work is focused on Covid-19 research. Researchers ship their samples to SSRL for experiments that are highly automated and then collect their data from the comfort of their home institutions, or even their own homes.
In the XCS hutch, the sample stands still while the detector moves on “train tracks” to look at it from various angles. Scientists use this hutch to look at tiny changes in X-ray diffraction produced by these changes in angle and learn more about the sample’s molecular structure.
In one such experiment, researchers studied the effects of a weak magnetic field on materials relevant to the data storage industry.
The accelerator lies in a tunnel 25 feet below the ground. The underground location promises stable temperature and humidity levels.
The Stanford Positron Electron Accelerating Ring (SPEAR) at SLAC was completed in 1972 and has been used by physicists to discover new particles, most notably the J/psi in 1974 and the tau in 1976. Since then it has undergone two major updates. Now known as SPEAR3, the ring is used exclusively for X-ray experiments at the Stanford Synchrotron Radiation Lightsource (SSRL).
Each year SPEAR3 is shut down for annual maintenance. During 2013’s shutdown, Craig Haggart, an operator at SPEAR3, showed us around and told us a bit about how SPEAR3 works.
Find out more about KIPAC HERE.. Did you know? SLAC’s first scientific discovery was not at all related to particle physics: Excavations for one of the experimental stations unearthed a 10-million-year-old fossil. It was a 9-foot-long aquatic mammal called Neoparadoxia repenningi, a distant relative of the modern-day manatee (this indicates that SLAC was once underwater). A replica of this fossil was assembled and mounted here at SLAC by Adele Panofsky, the wife of SLAC’s founding director, Wolfgang (Pief) K.H. Panofsky.
Preparing for an experiment in MEC
The CXI hutch is popular with scientists who study membrane proteins – gatekeeper molecules that control what goes in and out of cells. Although they are among the most medically significant biological molecules and the targets of half of all approved drugs, they are very hard to study with traditional X-ray sources like synchrotrons. LCLS is so bright that it can capture information from much smaller crystals of these proteins. This has allowed scientists to discover the detailed structures of a protein related to insect-transmitted African sleeping sickness and of another one, arrestin, that delivers signals between cells, among many other examples. Knowing the structure of arrestin could lead to better drugs for high blood pressure, diabetes and other medical conditions.
The MEC hutch is equipped with a powerful visible-light laser that can create extreme temperatures and pressures in a sample, which are then probed by X-ray laser pulses. The impressive experimental chamber where this happens is in the center of the room, with the laser enclosure surrounding it. A series of optical instruments and diagnostics channels the laser light into the chamber. LCLS is the only place that combines a laser this powerful with X-rays this bright.
The laser has two modes. One shoots a laser pulse every second and produces lower energy, and the other shoots only once every seven minutes, but produces very high energy. The maximum energy produced so far was 200 terawatts; this is more than the energy used by the entire U.S. electrical grid concentrated into a fraction of a second. Researchers are using these high energies to produce ever more exotic states of matter, similar to those in the cores of giant planets and in exploding stars.
In one experiment, the laser heated aluminum to 20,000 kelvins (four times hotter than the surface of the sun) and compressed it to a pressure 4,500 times higher than the deepest ocean depth, so the resulting changes in the aluminum could be studied with the X-ray laser. These studies bring us a step closer to understanding nuclear fusion, the process that powers stars, which scientists hope to harness as a new source of energy.
The XPP hutch is a versatile machine that can work with many types of samples.
The hutch has the same type of a robotic arm that’s used to assemble cars in factories. The arm moves the XPP detector to get the best angle for viewing a particular sample. , used to hold the detector and can be remotely controlled to move it to the right location relative to the sample. This robotic arm is the same as the ones used in the auto industry to assemble cars. It’s useful to have the detector oriented at various angles, since the sample doesn’t always diffract the X-rays in the same direction.
XPP iswas used to create molecular movies. One movie featured of the studied compounds was 1,3-cyclohexadiene, a ring-shaped molecule that serves as a model for studying what happens when sunlight hits our skin and triggers the synthesis of vitamin D. related to Vitamin D synthesis. In the experiments, laser light hit the molecule and broke open its ring, while X-rays made snapshots of the ultrafast movements of the atoms. Those snapshots were compiled into a molecular movie of the ring opening.
This was the first hutch opened in 2009, and for two years it was the only hutch.
It is used to image for imaging of small molecules and objects with [using soft X-rays, which are low-energy X-rays].
For example, Example of an experiment in the biological imaging field: Single particle imaging. This is a major international collaboration of over 100 scientists from 8 countries has been using AMO to work toward single particle imaging – , working toward the ultimate goal of making X-ray portraits of a single virus or living bacterium. These atomic-scale, detailed images would allow scientists to understand biological processes that are challenging to study with other techniques..
Computer vision helps SLAC scientists study lithium-ion batteries
New machine learning methods bring insights into how lithium-ion batteries degrade, and show it’s more complicated than many thought.
To learn more click HERE. The SXR hutch is similar to AMO, but has the ability to monochromate X-ray light (mono = “single”, chroma = “color”; “single color”). It can separate a specific “color” or wavelength of X-ray light from the beam and use it to hit the sample.
This is useful since it allows scientists to look at a specific type of atom they are interested in. One experiment that was done here studied photosynthesis, hoping to learn more about how plants use sunlight to split water and generate into oxygen; scientists would like to find a way to mimic that system to and make better catalysts and cleaner energy. They used athe single-colored beam from SXR to look at specific atoms involved in the process, and observe the electron flow that makes it possible.
The Stanford Synchrotron Radiation Lightsource (SSRL), a directorate of the SLAC National Accelerator Laboratory, is an Office of Science User Facility operated for the U.S. Department of Energy by Stanford University. SSRL provides synchrotron radiation, a name given to x-rays or light produced by electrons circulating in a storage ring at nearly the speed of light. These extremely bright x-rays can be used to investigate various forms of matter ranging from objects of atomic and molecular size to man-made materials with unusual properties.
SSRL produces extremely bright X-ray light for probing our world at the atomic and molecular level. More than 1,600 scientists from all over the world use it each year for research that benefits many sectors of the American economy. Their work spurs advances in medicine, energy production, environmental cleanup, nanotechnology and new materials. Researchers from a wide variety of fields have published almost 12,700 scientific papers based on work at SSRL since it opened in 1974.
Research at SSRL aids in the design of new drugs and next generation batteries. It helps make catalysts more efficient and reveals how to optimize the atom-by-atom structure of photovoltaic thin films that generate energy from sunlight. The goals are to make more effective medicines that have fewer side effects, improve the performance of alternative energy devices and develop greener processes for industry. In addition, fundamental studies of exotic materials at SSRL can pave the way for technologies of the future.
High-energy electrons zip through the linear accelerator at almost the speed of light and enter the football-field sized Undulator Hall. An undulator is a device that wiggles electrons back and forth between two rows of magnets, which have their poles arranged in an alternating positive-negative/negative-positive pattern. The negatively charged electrons are attracted to the positive poles. As they zigzag back and forth between the sets of magnets, they emit some of their energy in the form of X-rays. The emitted X-rays accumulate and reinforce each other with time and distance, creating a very bright, powerful and coherent beam we can use for research.
Public Lecture | Batteries for the Future: What's Possible?
Yi Cui, 2015
To view more public lectures click HERE.
The accelerator took four years to build (1962-1966) and was nicknamed "Project M" for monster. As one of 17 Department of Energy national labs, SLAC pushes the frontiers of human knowledge and drives discoveries that benefit humankind. We invent the tools that make those discoveries possible and share them with scientists all over the world.
SSRL research takes place at about 30 experimental stations, using extremely bright X-ray beams produced by the SPEAR3 storage ring. Visiting researchers have access to beamlines, instrumentation and ancillary equipment, all supported by dedicated staff scientists and technicians.
Researchers have been using Stanford-SLAC cryo-EM facilities to investigate the surface “spikes” that coronaviruses, including the one that causes COVID-19, use to infect cells. They’re also trying to figure out which fragments of SARS-COV-2 RNA would be the most effective target for therapeutic drugs. These studies provide important information for developing the next generation of drugs and vaccines against COVID-19 and other coronavirus strains.
SLAC National Accelerator Laboratory is funded by the Department of Energy (DOE) and operated by Stanford University.
One of 17 DOE national labs, it’s a powerhouse for science and technology at a scale no single university or state could support.
SLAC began in 1962 with 200 employees. Now more than 1,600 people are on staff, in addition to over 400 postdoctoral researchers and graduate students and 66 faculty. SLAC people are Stanford employees.
Originally built for studying elementary particles, SLAC saw nearly 50 years of particle collision experiments. Three of four Nobel prizes were awarded to SLAC researchers for new particles discovered using our accelerator.
SLAC’s last collision experiment closed in 2008, and SLAC’s linear accelerator was reinvented as the world’s brightest X-ray source.
SLAC houses three DOE Office of Science user facilities (LCLS, SSRL and FACET) where visiting scientists can do experiments.
Making Science Happen
Science that’s changing the world from the heart of Silicon Valley and the people who are making it happen.
The Worlds Within
This 1964 promotional documentary about the origin of the Stanford Linear Accelerator Center (SLAC), later re-named SLAC National Accelerator Laboratory, follows its early development and construction. Featuring narrated segments by Wolfgang K.H. Panofsky, SLAC architect Bill Kinst, and others, the film is intended to describe the work of physicists to a wide audience.
SLAC Introduction
This documentary chronicles SLAC's history, shares personal experiences from some of its directors, scientists and innovators, and offers a glimpse into the many projects we're working on today.
SLAC From the Sky
Spread across 426 acres, SLAC National Accelerator Laboratory’s campus boasts an array of distinctive and historic buildings, headlined by the 2-mile-long klystron gallery, the building that sits on top of the longest linear particle accelerator in the world. This video, shot using drones, gives an overview of the lab and the science being done inside its various facilities.
SLAC Timeline
1962: Contract execution and start of accelerator construction
1966: Construction completed and research begins
1967: 20-GeV electron beam achieved
1968: First evidence discovered for quarks
1972: SPEAR operations begin
1973: Stanford Synchrotron Radiation Project (SSRP) started
1974: Discovery of psi particle
1976: Discovery of charm quark and tau lepton
1976: Nobel Prize shared by SLAC's Burton Richter for the J/psi discovery
1977: SSRP becomes Stanford Synchrotron Radiation Laboratory (SSRL)
1980: PEP operations begin
1982: Wolf Prize awarded to SLAC's Martin Perl for discovery of the tau lepton
1989: SLC operations begin; 50 GeV electron and positron beams achieved
1990: Nobel Prize shared by SLAC's Richard Taylor for first evidence that nucleons consist of quarks
1990: SPEAR becomes a dedicated synchrotron radiation facility with its own independent injector
1992: SSRL becomes a division of SLAC
1993: Final Focus Test Beam facility constructed
1994: Initiation of the PEP-II project to build the Asymmetric B Factory
1995: Nobel Prize in Physics shared by Martin Perl for the discovery of the tau lepton.
1996: NLCTA project initiated
1997: First beam injected into B Factory
1998: First B Factory particle collision occurs
1999: First events recorded by B Factory's BaBar detector
2000: Joint NASA-Stanford GLAST project initiated, Helen Quinn shares Dirac Medal
2002: SLAC celebrates 40th anniversary, LCLS project approved
2003: Kavli Institute for Particle Astrophysics and Cosmology established
2006: Roger Kornberg awarded Nobel Prize in Chemistry for RNA polymerase work done partly at SSRL
2008: NASA’s Fermi Gamma-ray Space Telescope begins mapping the sky; SLAC built and operates the main instrument for the international project
2009: Linac Coherent Light Source (LCLS) sees first light
2011: First beam delivered to the Facility for Advanced Accelerator Experimental Tests (FACET)
2012: SLAC’s ATLAS technology contributes to Higgs boson discovery at CERN’s Large Hadron Collider
2012: SLAC celebrates 50th anniversary
2015: Construction begins at Large Synoptic Survey Telescope (LSST) site in Chile (now known as the Vera C. Rubin Observatory)
2016: Responding to a call to build a revolutionary new X-ray laser, SLAC begins construction on LCLS-II
SLAC has six state-of-the-art electron microscopes onsite, including Krios microscopes like the one shown in the background image.
SLAC's particle accelerators provide intense beams of high energy electrons, positrons and X-ray photons. Experiments using these beams have resulted in important discoveries and advances in high energy particle physics, chemistry, biology and materials science. These achievements are widely recognized and have led to four Nobel prizes.
Nobel Prizes in Physics
1976 - Charm: The 4th Quark
1990 - Quarks Revealed: Structure Inside Protons and Neutrons
1995 - Tau: The Third Electron-Like Particle
Nobel Prize in Chemistry
2006 – Transcription: How DNA’s Orders are Carried Out
The LSST camera being built at SLAC is the size of a small car and weighs more than 3 tons. The 3.2-gigapixel camera will be the largest digital camera ever built for ground-based optical astronomy.
Spread across 426 acres, SLAC National Accelerator Laboratory’s campus boasts an array of distinctive and historic buildings, headlined by the 2-mile-long Klystron Gallery, the building that sits on top of the longest linear particle accelerator in the world.
The gallery houses klystrons, microwave pulse generators that pump accelerating energy into the electron beam.
The Klystrons
Klystrons generate power for accelerating particles. You can see a few of them in this photo; they are the red cylinders. There are more than 240 of them in the Klystron Gallery. Klystrons were invented at Stanford by the Varian brothers. They are massive microwave generators, each of them producing power pulses 60,000 times stronger than a kitchen microwave oven. The klystrons send microwaves to the accelerator, which is 25 feet below ground.
The Cryo-EM (cryogenic electron microscopy) facility at SLAC, built and operated in partnership with Stanford University, is equipped with multiple state-of-the-art instruments for cryo-EM, a groundbreaking technology whose rapid development over the past few years has given scientists unprecedented views of the inner workings of the cell.
Currently the Cryo-EM facility has 6 flagship 300kV Titan Krios Transmission Electron Microscopes on site, with an additional 200kV Talos Arctica. The rapid development of direct electron detectors, improved electron emitter and column design, an autoloader system for loading multiple samples, and the development of computational software and enhanced data storage have led to an exponential growth and ‘resolution revolution’ in the field of cryo-EM.
In these images we see the internal anatomy of the Titan Krios, from the 300kV electron source at the top, through the column containing electromagnetic lenses, the sample loader and stage, and different electron detectors. Energy filtering (near the bottom) improves contrast, signal to noise ratio and consequently the achievable resolution of the system. Recent efforts to characterize spike proteins in especially the SARS-Co-V2 virus have played a significant role in antibody discovery and vaccine development.
SLAC is helping to build and test the LUX-ZEPLIN or LZ detector, one of the biggest and most sensitive detectors ever designed to catch hypothetical dark matter particles known as WIMPs.
Researchers at the Department of Energy’s SLAC National Accelerator Laboratory are on a quest to solve one of physics’ biggest mysteries: What exactly is dark matter – the invisible substance that accounts for 85 percent of all the matter in the universe but can’t be seen even with our most advanced scientific instruments?
Most scientists believe it’s made of ghostly particles that rarely bump into their surroundings; that’s why billions of dark matter particles might zip right through our bodies every second without us even noticing. Leading candidates for dark matter particles are WIMPs, or weakly interacting massive particles.
Now SLAC is helping to build and test one of the biggest and most sensitive detectors ever designed to catch a WIMP – the LUX-ZEPLIN or LZ detector.
What is Cryo-EM?
Cryogenic electron microscopy (cryo-EM) is a version of electron microscopy, which was invented in the 1930s. These microscopes use beams of electrons rather than light to form images of samples. Because the wavelength of an electron is much shorter than the wavelength of light, electron beams reveal much smaller things.
In the mid-1970s, scientists came up with the idea of chilling samples into a glass-like state to preserve the natural structure of biological specimens and reduce damage from the electron beam, and cryo-EM was born. The technology slowly evolved, and then a few years ago took a giant leap, thanks to dramatic advances in detectors and software. In 2017 three scientists were awarded the Nobel Prize in chemistry for their roles in developing cryo-EM.
Today, cryo-EM can generate 3-D images at atomic resolution of viruses, molecules and complex biological machines inside the cell, such as the ribosomes where proteins are synthesized. By flash-freezing these tiny things in their natural environments, scientists can see how they are built and what they do in much more detail than before, stringing thousands of images together to create stop-action movies and even taking virtual “slices” through cells, much like miniature CT scans. Meanwhile, cryo-EM instruments have become easier to use and much more accessible.
The cryo-EM facility at SLAC, built and operated in partnership with Stanford University, is equipped with multiple state-of-the-art instruments for cryo-EM, giving scientists unprecedented views of the inner workings of the cell.
Public Lecture | Cryo-EM: Amazing 3-D Views of Life’s Molecular Machines.
Wah Chiu, 2018
To view more public lectures, click HERE.
Photos from the Stanford-SLAC cryo-electron microscopy (cryo-EM) facilities.
In 2018 Stanford and SLAC opened one of the world's most advanced cryo-EM facilities on the SLAC campus. To learn more click HERE. In 1962, in the rolling hills west of Stanford University, construction began on what was then the longest and straightest structure in the world, the Stanford Linear Accelerator, or linac. It took four years to build and was affectionately known as "the Monster" to the scientists who conjured it. Building the 2-mile-long structure was an engineering challenge that required taking the Earth’s curvature into account (a 20-inch shift in the vertical axis). Electrons fired from one end of the gallery reached 99.999% of the speed of light in the first meter of their flight down the accelerator and collided with a target or particle beam at the other end.
Of the four Nobel prizes awarded to SLAC scientists, three were for discovering novel elementary particles using the linac. Today the SLAC linac provides a unique source of X-ray laser pulses for investigating matter at the smallest and fastest scales at the Linac Coherent Light Source (LCLS) as well as serving as a testbed for R&D into future accelerator technologies.
Find out more about LSST's research HERE.
Find out more about our LCLS facility HERE.
The dark matter filaments are separated by vast regions of much lower average density of dark matter and galaxies, so-called cosmic voids.
The dark matter filaments are separated by vast regions of much lower average density of dark matter and galaxies, so-called cosmic voids.
The most massive clusters of galaxies reside at the intersection of filaments of dark matter, inside very massive so-called dark matter haloes.
The XPP (X-ray Pump Probe) instrument predominantly uses a fast optical laser to generate transient states of matter, which are probed with hard X-ray pulses from LCLS. This reveals changes in the sample’s structure initiated by the laser excitation.
The XCS (X-ray Correlation Spectroscopy) instrument observes dynamical changes of large groups of atoms in condensed matter systems over a wide range of time scales.
The CXI (Coherent X-ray Imaging) instrument takes advantage of extremely bright, ultrashort LCLS pulses of hard X-rays to allow imaging of non-periodic nanoscale objects, including single or small clusters of biomolecules at or near atomic resolution.
The MFX (Macromolecular Femtosecond Crystallography) instrument primarily uses short pulses of X-rays to limit damage to samples during the exposure. This allows, for example, the study of metal-containing macromolecules that are particularly sensitive to radiation damage due to the high absorption of X-rays by the metal atoms.
The MEC (Matter in Extreme Conditions) instrument at SLAC gives scientists tools to investigate the extremely hot, dense matter at the centers of stars and giant planets. These experiments could help researchers design new materials with enhanced properties and recreate the nuclear fusion process that powers the sun.
Galaxies form along elongated filaments of dark matter, as shown at the location of this icon.
Galaxies form along elongated filaments of dark matter, as shown at the location of this icon.
The AMO (Atomic, Molecular & Optical Science) instrument is situated on one of the soft X-ray branches of the LCLS that delivers intense, ultrashort pulses of X-rays from the free-electron laser. It allows scientists to study the interaction between the extremely intense LCLS X-ray pulses, atoms and molecules.
The SXR (Soft X-ray Materials Science) instrument allows researchers to apply the high brightness and timing capability of the LCLS to scattering and imaging experiments that require the use of soft X-rays.
There are 32 undulators with 3,000 pairs of magnets in the Undulator Hall, spread out over 100 meters.
Sensors of world’s largest digital camera snap first 3,200-megapixel images at SLAC.
The camera will explore cosmic mysteries as part of the Rubin Observatory’s Legacy Survey of Space and Time.
X-ray Laser Animated Fly-through
Take a tour with an electron's-eye-view through SLAC's revolutionary new X-ray laser facility with this 5 1/2 minute animation. See how the X-ray pulses are generated using the world's longest linear accelerator along with unique arrays of machinery specially designed for this one-of-a-kind tool.
For more than 40 years, SLAC's two-mile-long linear accelerator (or linac) linac has produced high-energy electrons for cutting-edge physics experiments. In 2009 SLAC's linac entered a new phase of its career with the creation of the Linac Coherent Light Source (LCLS).
LCLS produces pulses of X-rays more than a billion times brighter than the most powerful existing sources, the so-called synchrotron sources which are also based on large electron accelerators.
The ultrafast X-ray pulses are used much like flashes from a high-speed strobe light, enabling scientists to take stop-motion pictures of atoms and molecules in motion, shedding light on the fundamental processes of chemistry, technology, and life itself.
What happens to the electrons when they are done generating x-rays?
A powerful magnet directs them down into the “beam dump,” where they’re absorbed by a piece of metal in the ground. Meanwhile, the coherent X-rays are unaffected by the magnet and keep moving forward to the experimental halls.
Find out more about SSRL HERE. Microwaves from klystrons above ground travel through waveguides to the accelerator structure below ground.
This visualization is based on a computer simulation of the large-scale structure formation in the Universe. It shows a region about 400 million light years across, starting shortly after the Big Bang when the dark matter was distributed almost uniformly throughout space. Tiny density fluctuations were amplified due to gravity, giving rise to a filamentary structure, called the cosmic web, which is depicted in black in this color scheme. Due to their gravitational pull, the densest regions of dark matter, so-called “dark matter halos” (color-coded in yellow/orange) attract baryonic matter. This is mainly hydrogen, which collapses and forms stars and galaxies. (The underlying computer simulation did not model baryonic matter, star or galaxy formation processes.)
Public Lecture | A Sparkle in the Dark: The Outlandish Quest for Dark Matter
Maria Elena Monzani, 2019
To view more public lectures click HERE. The search for dark matter -- and what we've found so far | Risa Wechsler
Roughly 85 percent of mass in the universe is "dark matter" -- mysterious material that can't be directly observed but has an immense influence on the cosmos. What exactly is this strange stuff, and what does it have to do with our existence? Astrophysicist Risa Wechsler explores why dark matter may be the key to understanding how the universe formed -- and shares how physicists in labs around the world are coming up with creative ways to study it.
Searching for Dark Matter, the LUX and LZ Experiments - Dan Akerib
Dark Matter remains a profound mystery at the intersection of particle physics, astrophysics, and cosmology. One of the leading candidates, the Weakly Interacting Massive Particle, or WIMP, may be detectable using terrestrial particle detectors. Recent technological advances are enabling very rapid increases in sensitivity in the search for these particles. I will talk about the LUX experiment, a liquid xenon time projection chamber, which currently holds the best upper limit over much of the WIMP mass range. I will also discuss plans for a larger follow up experiment, LZ, which will just begin to measure a background neutrino signal that will set a fundamental limit our ability to search for WIMP dark matter.
This movie shows a large cluster of several hundred galaxies in the foreground. Most of the mass of the cluster is contributed by so-called dark matter, probably a new type of subatomic particle that does not interact with light and therefore is invisible, but has mass and can be observed indirectly by its gravitational effects on visible matter. According to Einstein’s theory of gravity, the cluster’s huge mass substantially warps the nearby space-time structure, causing a deflection of light particles that pass through the region. This results in a distortion of the images of background galaxies, visible as arc-like structures around the cluster - an effect that is called gravitational lensing. In the first part of the movie, the camera rotates around the center of the cluster. Next, we see the orbital motion of the individual galaxies around the center of mass over time-scales of several hundred million years. The last part shows the hypothetical effects of stripping the invisible dark matter off the cluster: without the gravitational force contributed by the dark matter, the orbits of the galaxies are not stable anymore and the cluster dissolves. At the same time, the gravitational lensing almost vanishes.
Only about five percent of the total matter and energy of the Universe is made of the same familiar matter that makes up everything from stars to planets to human beings. The identity of the remaining 95 percent, roughly one-third known as "dark matter" and roughly two-thirds as "dark energy," is unknown. Though scientists have not yet detected it directly in laboratories on Earth, dark matter’s existence has been deduced from its gravitational effects, seen affecting individual galaxies all the way up to the entire observable Universe. Its prevalence and physical effects have ensured dark matter a crucial place in cosmological theory because of its key role in defining the structure of the Universe and in binding all galaxies—even our own Milky Way—together. Modern astrophysics and particle physics theory suggests that dark matter exists in the form of a yet undiscovered elementary particle.
Most such models predict that dark matter particles can self-annihilate. This happens when two dark matter particles collide. When particles strike one another, energy is released in the form of detectable standard model elementary particles such as photons or charged particles such as anti-electrons and electrons. Many dark matter models predict the emission of gamma rays, the highest energy photons, as annihilation products. KIPAC researchers are using gamma-ray data from the Fermi Large Area Telescope (LAT) to search for the annihilation products. In order to search for these products, the astrophysical foreground has to be well understood before detections or limits on these particles can be derived.
A second way to look for these dark matter particles is with specialized detectors that are well-shielded from conventional sources of radiation, and to look for minute energy transfers that are expected when these particles occasionally strike an atomic nucleus in the detector. KIPAC researchers are attempting to detect dark matter with two major research programs: The Super Cryogenic Dark Matter Search (Super CDMS) uses silicon and germanium solid state detectors that are cooled close to absolute zero, and are sensitive to very small temperature changes when a dark matter particle transfers energy to the nucleus of an atom in the detector. The LUX-ZEPLIN (LZ) program uses vessels filled with liquid xenon and senses small amounts of scintillation light produced when the nucleus of a xenon atom in the detector is struck.
Picture of Distant Worlds- Discover our Universe
Join us as Prof. Bruce Macintosh (Stanford University) presents the first public lecture in our 'Discover Our Universe' series followed by live online Q&A.
In the past two and a half decades, more than 4000 planets have been discovered orbiting other stars beyond our own Solar System. This has sparked a revolution in astronomy as we realize our Solar System is not alone. However, we still don’t know if our Solar System is rare or unique — the powerful techniques that detect extrasolar planets have discovered systems very different than our own. In recent years, advances in technology have allowed a handful of giant planets to be imaged directly.
Find out about the first-ever images of other solar systems — and the technology that has allowed us to discover them, such as the Gemini Planet Imager — as well as the future planet-hunting space telescopes. The ultimate goal is detection of a second ‘pale blue dot’—an Earth twin where we could even see the biosignatures of extrasolar life. Such a discovery will truly complete the evolution of our view of the Universe.
Direct Imaging of Exoplanets - Bruce Macintosh
Learn about an exciting new exoplanet discovery—a Jupiter-like planet called “51 Eri b” that orbits a star a 100 light years away in the constellation of Eridanus.
Using a powerful new imaging device, astronomers have spied a Jupiter-like exoplanet 100 light-years distant in the constellation of Eridanus. Unlike most planets found around other stars, 51 Eri b has been seen directly. The instrument employed to make the discovery has also made a spectroscopic analysis of the light reflected from the planet, and has detected gases similar to those in Jupiter’s atmosphere.
Because GPI not only images exoplanets but also spreads their light for chemical analysis, astronomers can search for such common gases as water and methane in their atmospheres. Researchers had expected to see methane in directly-imaged exoplanets based on the temperature and chemistry of these worlds, but had failed to detect these molecules in large quantities using earlier instruments. However, the observations of 51 Eri b made with GPI have clearly revealed a methane-dominated atmosphere similar to that of Jupiter.
An extraordinarily complex instrument the size of a small car, GPI is attached to one of the world’s biggest telescopes – the 8-meter Gemini South instrument in Chile. It began its survey of stars last year.
The host star, 51 Eri, is very young, a mere 20 million years old, and is slightly hotter than the Sun. The exoplanet 51 Eri b, whose mass is estimated to be roughly twice that of Jupiter, appears to orbit its host star at a distance 13 times greater than the Earth-Sun distance. If placed in our own solar system, 51 Eri b’s orbit would lie between those of Saturn and Neptune.
More than 4000 planets have been discovered orbiting other stars. These extrasolar planets, or exoplanets, span a vast range of properties, and most form systems very different than our own, ranging from "hot Jupiters," gas giants that are closer to their stars than Mercury is to our Sun, to tightly-packed systems of multiple "super-earths" orbiting faint red stars. Planets are hundreds of thousands of times to billions of times fainter than stars, making them nearly impossible to detect. The vast majority of these planets have been discovered through indirect techniques—changes in the parent star’s velocity or brightness caused by the presence of a planet. The exoplanet group at Stanford specializes in direct imaging of exoplanets, blocking out the light of the parent star to separate the planetary signal. With current technology such as the Gemini Planet Imager (GPI), this is only practical for massive young planets—the equivalent of our Jupiter, but only tens of millions of years old and shining brightly in infrared with the heat released by their formation. Once these planets are detected, we can use spectroscopy to characterize them and determine their atmospheric compositions and natures. Ultimately, the same technology will be applied to study Earth-like planets, allowing us to probe their atmospheres and hunt for chemical compositions that could indicate life.
It is generally believed that most of the elements in the universe heavier than helium were created in stars when lighter nuclei fuse to make heavier nuclei. The process is called nucleosynthesis. So we are all made out of star stuff.
The Cosmic Web: According to the standard model of Big Bang Cosmology, dark matter drives the formation of the largest structures of the Universe, the so-called cosmic web.
This foam-like structure consists of three main building blocks: Filaments/walls (green circle), halos (red circle) and voids (blue circle). Click on the icons
close to the circles to zoom in closer and learn more.
Based on observations of the motions of nearby stars, theory predicts that there is about one dark matter particle per coffee mug-sized volume of space.
Over the course of a human lifetime, about 1 milligram of dark matter has passed through you.
Earthquakes were taken into consideration when planning and designing the accelerator. The strongest earthquake this facility has experienced was the 6.9-magnitude Loma Prieta quake in 1989. Despite heavy damages in neighboring communities, the accelerator was only slightly misaligned, and reopened after a month of realignment and testing.
LCLS has two experimental halls with seven hutches, or experimental stations.
Each hutch specializes in a particular subset of LCLS capabilities, allowing scientists to do experiments with specific types of samples, wavelengths of X-rays and types of detectors.
X-rays come into the hutch from the right side and travel through the pipes into the experimental chamber, where they hit the sample. They are then diffracted or scattered into a detector or absorbed by the sample, producing other particles that go on to hit the detector.
The image formed in the detector helps scientists analyze the atomic structure or other properties of the sample (this is similar to looking at a person’s shadow and trying to find out what they look like).
Most of our experiments are done in a powerful vacuum, to avoid air or other molecules blocking the X-rays on their way to the sample. To make sure the vacuum is complete and no water or other molecules are trapped in the pipes, the equipment is wrapped in foil and baked at around 500 degrees.
In most of our hutches, scientists can trigger reactions or excite samples using an optical laser. Laser light is adjusted at the laser enclosure in the center of the room, and lenses direct it toward the sample. We can use the optical laser to start a reaction, heat the sample, create high pressures, rotate molecules, etc. This is an integral part of making a molecular movie.
To reduce the risk of X-ray exposure, no one is allowed in the hutches during experiments. Researchers remotely control the scientific equipment from an adjacent control room.
LSST Simulator
Using a mass simulator, our LSST Camera crew tested the assembly stand for the telescope’s 3,200-megapixel digital camera. The test mass is shaped like the future camera but is a quarter heavier (8,500 pounds).
Fabrication of the accelerator structure
This 1964 technical documentary details the fabrication and assembly of components to construct the Stanford Linear Accelerator structure.
Public Lecture | Super-Human Operator: Controlling Accelerators with Machine Learning
Auralee Edelen, 2019.
To view more public lectures, click HERE. Construction of the linac beam housing included the building of a penetration shaft for materials handling access. When complete, the beam housing was covered with 25 feet of earth, which separate it from the Klystron Gallery above.
Did you know? SLAC Market, SLAC's pop-up gift shop, sells a mini model of the accelerator that’s suitable for kids and adults alike. You can buy one once SLAC's public tours resume.
X-ray Laser Animated Fly-through
Take a tour with an electron's-eye-view through SLAC's revolutionary new X-ray laser facility with this 5 1/2 minute animation. See how the X-ray pulses are generated using the world's longest linear accelerator along with unique arrays of machinery specially designed for this one-of-a-kind tool.
For more than 40 years, SLAC's two-mile-long linear accelerator (or linac) linac has produced high-energy electrons for cutting-edge physics experiments. In 2009 SLAC's linac entered a new phase of its career with the creation of the Linac Coherent Light Source (LCLS).
LCLS produces pulses of X-rays more than a billion times brighter than the most powerful existing sources, the so-called synchrotron sources which are also based on large electron accelerators.
The ultrafast X-ray pulses are used much like flashes from a high-speed strobe light, enabling scientists to take stop-motion pictures of atoms and molecules in motion, shedding light on the fundamental processes of chemistry, technology, and life itself.
Black Holes: The End of Time or a New Beginning?
Dr. Roger Blandford (Kavli Institute, Stanford University)
While black holes are popularly associated with death and doom, astrophysicists increasingly see them as creators, not destroyers — playing a major role in the formation and evolution of galaxies, stars, and planets. Dr. Blandford (whose research interests include black holes, galaxies, and cosmology) summarizes why scientists now think that black holes of various sizes actually do exist, describes some of their strange properties, and explains their "environmental impact" on the universe at large.
Making a Molecular Movie: How it Works
This video explains the basics of how scientists at SLAC National Accelerator Laboratory use powerful X-rays from the Linac Coherent Light Source to make molecular movies.
10 ways SLAC’s X-ray laser has transformed science
In the decade since LCLS produced its first light, it has pushed boundaries in countless areas of discovery....
To learn more click HERE. How Things in the Universe Came About and How They Ended Up Within Us
Dr. Abel takes us on an illustrated journey through the early stages of the universe, using the latest computer animations of how the first (massive) stars formed and died, and how stars built up the first galaxies. He also discusses how the early stars seeded the cosmos with the chemical elements necessary for life.
This visualization is based on a simulation of the formation of the first stars in the Universe, following the collapse of hydrogen gas in a so-called proto-galaxy about 10,000 light-years across. Simulations like this predict that the first stars were very massive, up to several 100 solar masses and formed as early as 100 million years after the Big Bang. Stars of this mass have relatively short lifetimes (in the order of several million years), which would explain why stars like these have not been detected yet.
Making a Molecular Movie: How it Works
This video explains the basics of how scientists at SLAC National Accelerator Laboratory use powerful X-rays from the Linac Coherent Light Source to make molecular movies.
Public Lecture | Seeing is Exploding: Snapping Biological Images with X-ray Laser Blasts
Sebastien Boutet, 2019
To view more public lectures click HERE.
Did you know? Each LCLS hutch is color coded to help scientists stay organized and easily identify their hutch’s tools.
Despite spending many hours conducting experiments, SLAC's scientists still find creative ways to make their lab environment fun!
Ask Symmetry - What is the universe made of?
Risa Wechsler of the Kavli Institute for Particle Astrophyiscs and Cosmology discusses how scientists know what percentages of the universe are made up of normal matter, dark matter and dark energy.
Public Lecture | Liquid Diamonds: New Materials at Pressures of the Earth's Core
Emma McBride, 2018.
To view more public lectures click HERE. The Making of the Largest 3D Map of the Universe
DESI, the Dark Energy Spectroscopic Instrument, will mobilize 5,000 swiveling robots – each one pointing a thin strand of fiber-optic cable – to gather the light from about 35 million galaxies. The little robots are designed to fix on a series of preselected sky objects that are as distant as 12 billion light-years away.
By studying how these galaxies are drifting away from us, DESI will provide precise measurements of the accelerating rate at which the universe is expanding. This expansion rate is caused by an invisible force known as dark energy, which is one of the biggest mysteries in astrophysics and accounts for about 68 percent of all mass and energy in the universe.
In this video, DESI project participants share their insight and excitement about the project and its potential for new and unexpected discoveries.
One of the most important and surprising scientific discoveries of the twentieth century is that the expansion of space is not slowing down, but speeding up—contrary to what we expect the gravitational pull of all the matter in the Universe to do. The driver of this accelerating expansion has been labeled "dark energy," but there is much about the phenomenon that researchers don’t understand. We now know that dark energy comprises the bulk of the energy density of the Universe, but its existence poses major challenges to our basic understanding of fundamental forces at work in the cosmos. On the other hand, the incorporation of dark energy into the prevailing theory of cosmology has been enormously successful. For example, in earlier cosmological models, the Universe appeared to be younger than its oldest stars. When dark energy is included in the model, that problem goes away.
The spectrum below compares the wavelengths of waves and other forms of electromagnetic radiation to the sizes of familiar objects.
X-ray Laser Animated Fly-through
Take a tour with an electron's-eye-view through SLAC's revolutionary new X-ray laser facility with this 5 1/2 minute animation. See how the X-ray pulses are generated using the world's longest linear accelerator along with unique arrays of machinery specially designed for this one-of-a-kind tool.
For more than 40 years, SLAC's two-mile-long linear accelerator (or linac) linac has produced high-energy electrons for cutting-edge physics experiments. In 2009 SLAC's linac entered a new phase of its career with the creation of the Linac Coherent Light Source (LCLS).
LCLS produces pulses of X-rays more than a billion times brighter than the most powerful existing sources, the so-called synchrotron sources which are also based on large electron accelerators.
The ultrafast X-ray pulses are used much like flashes from a high-speed strobe light, enabling scientists to take stop-motion pictures of atoms and molecules in motion, shedding light on the fundamental processes of chemistry, technology, and life itself.
In seeking to understand the cosmology of the early Universe, scientists have been able to apply the current laws of physics to the extremely high-energy conditions of the primordial Universe, allowing us to explore the laws of physics at energy scales far greater than what is achievable in man-made particle accelerators. This new application of physics shows the deep connections between the fundamentals of the early Universe and the principles of theoretical particle physics.
Research:
KIPAC researchers are heavily focused on understanding the origin of the early Universe, a period in which very different rules of physics were at play in the cosmos than those that govern it now. It is believed that the Universe began with very high energies. To tease apart the forces that touched off the Universe’s expansion—some 14 billion years ago—KIPAC scientists are using an array of instruments such as telescopes and satellites to look as far away and as far back in time as possible.
Among the most important observational tools in KIPAC’s exploration of the early Universe are instruments that measure irregularities in the cosmic microwave background radiation (CMB), such as the WMAP and Planck satellites. By looking at the distribution of the irregularities in the CMB, for example, KIPAC researchers are attempting to reconstruct the quantum conditions of the early Universe and understand the laws governing its dynamics at the beginning. By looking back, scientists may also deduce the existence of new particles, forces or dimensions in existence during the Universe’s first moments and, in turn, gain a more comprehensive understanding of the laws of the present Universe.
Join us as Dr. Jessie Muir (Stanford University) discusses Echoes of the Early Universe — How the oldest observable light can teach us about fundamental physics in our 'Discover Our Universe' public lecture series followed by live online Q&A.
This simulation shows how the first galaxies in the Universe, which might have formed a couple of hundred million years after the Big Bang, could have heated up and ionized the intergalactic material with high-energetic light emitted by their massive young stars. In this process, the material, mainly hydrogen gas, became transparent, which ended the so-called dark ages of the Universe. In this visualization, neutral hydrogen gas is displayed using opaque dark colors, whereas transparent blue depicts bubbles of ionized gas. The location of young (dwarf) galaxies is indicated by the white fussy points. The process probably started about half a billion years after the Big Bang and took several hundred million years to finish. The region shown is about 400 million light-years across.
LSST's Clean Room
Assembling the LSST Camera requires a super clean environment because any dust settling on the image sensors would degrade their precision performance. The air inside the facility is about 1,000 times “cleaner” than ordinary air. The main 1,875-square-foot work space has a 24-foot ceiling so the approximately 10-foot-long camera body can be mounted vertically for optical alignment and final testing.
Weaving the Search for Dark Matter
SLAC sends off four custom-woven grids for the LUX-ZEPLIN underground dark matter detector. Meet some of the people on this quest.
Did you know? The LZ experiment contains 10 metric tons of liquid xenon!
Some xenon facts:
• The xenon that goes into LZ has to be purified to reduce of krypton contamination, down to a level of 15 parts per quadrillion! (The For comparison, the xenon starts out with about we buy contains closer to 15 parts per billion of krypton, so that’s a reduction of a millionth in the level of krypton. before we purify it.)
• Xenon makes up 0.0000087% of the air we breathe and is obtained by extracting it from the air.
• Other uses for xenon include xenon lamps, lasers, satellite and rocket propulsion, creating silicon microprocessors, and even making drugs to treat cancer.
The LUX-ZEPLIN (LZ) group at SLAC is carrying out a broad range of hardware development, detector and background modeling, and xenon purification for the project.
The LZ experiment is located nearly a mile underground in an old gold mine in South Dakota.
Public Lecture | How to Bend a Stream of Dark Matter and Make it Shine
Sebastian Ellis, 2019
To view more public lectures click HERE.
What is Dark Matter?
Based on measurements of ancient radiation left over from the Big Bang, scientists know that ordinary matter –- the stuff that makes up you, me, and all of the observable stars and galaxies –- only accounts for only about 5% of the total energy in the universe. The remaining 95% is still unexplained, but here at SLAC , we’re working on tracking it down.
About 70% of the cosmos consists of dark energy, which is accelerating the expansion of the universe, and the rest – about 25% – About a quarter of the cosmos is dark matter, which rarely interacts with ordinary matter. Scientists know that dark matter exists because it affects the rotation of galaxies and bends the path of light. Most researchers think it’s made of yet-to-be-discovered particles. Here at SLAC, we’re helping to design the LUX-ZEPLIN experiment, which will hopefully help us directly detect this particle.
The idea behind LUX-ZEPLIN is that when a dark matter particle flies into the detector and hits a xenon atom, the atom will shake. This shaking creates a burst of light that’s picked up by sensors at the top and bottom of the detector. The shaking will also liberate electrons, which drift to the top of the liquid, cross into a layer of gas and create another burst of light. From this combination of signals, scientists will be able to pinpoint the spot in the detector where the dark matter collision happened. It’s kind of like listening for the thunderclap after a lightning strike to tell how far away the lightning is. SLAC is assembling a detector prototype and purifying liquid xenon for the experiment.
These cryo-EM images show how ovarian cancer changes platelets in a patient’s blood. The platelet cells in the top row are from healthy people, and have a continuous circular ring of microtubules (dark blue). In platelets from ovarian cancer patients, bottom, those rings are shorter, broken and disrupted. These changes might someday offer a way to diagnose the disease.
Public Lecture | A Sparkle in the Dark: The Outlandish Quest for Dark Matter
Maria Elena Monzani, 2019.
To view more public lectures click HERE. The LUX-ZEPLIN (LZ) detector is one of the biggest and most sensitive detectors ever designed to catch hypothetical dark matter particles known as weakly interacting massive particles (WIMPs).
Public Lecture | 10 Years of Cosmic Fireworks with the Fermi Gamma-ray Space Telescope
Eric Charles, 2018.
To view more public lectures click HERE. Supermassive black holes, with up to several hundred billion solar masses, are probably hosted at the center of every larger galaxy. Surrounded by accretion disks of magnetized material, the spinning black holes can bundle magnetic field lines along their polar axes, generating extremely energetic jets of charged particles. In this animation from a supermassive black hole simulation, the jet rams into the surrounding accretion disk (infalling hot plasma as white-red near the hole) and causes the disk to align with the black hole spin axis near the black hole.
When astronomers refer to “compact objects,” they are generally referring to objects significantly more dense than a typical star or a planet. For example, white dwarfs and neutron stars are extremely dense objects that result when their progenitor stars—Sun-like stars or smaller in the case of white dwarfs, and giants in the case of neutron stars—have run out of fuel for fusion. The stars are no longer able to produce a sufficient amount of radiation pressure in their cores to prevent their outer layers from collapsing. When the biggest stars collapse, they can trigger the formation of black holes—regions of space in which gravity is so strong that even light cannot escape. Black holes with masses comparable to that of the Sun are scattered through the Milky Way and neighboring galaxies. Scientists also have found strong evidence of massive black holes—a million or more times more massive than the Sun—in the centers of many galaxies. In fact, one of these supermassive black holes sits at the heart of our very own Milky Way.
Compact objects are subjects of intense research at KIPAC, whose scientists study them using data from the Fermi Gamma-ray Space Telescope. The gamma-ray emissions from pulsars allow researchers to study how their intense, pulsed radiation is produced. Researchers now believe that the type of neutron star called pulsars behave like powerful magnets in which the poles are not aligned with the axis of the star's rotation. The energetic particles emanating from a pulsar form a beacon—similar to the beam of the lighthouse—which periodically sweeps across our line of sight once or twice per revolution. By taking an accurate count of pulsars, KIPAC scientists have been able to estimate how often stellar collapses take place in the Milky Way.
Supermassive black holes, with up to several hundred billion solar masses, are probably hosted at the center of every larger galaxy. Surrounded by accretion disks of magnetized material, the spinning black holes can bundle magnetic field lines along their polar axes, generating extremely energetic jets of charged particles. In this animation from a supermassive black hole simulation, the jet rams into the surrounding accretion disk (infalling hot plasma as white-red near the hole) and causes the disk to align with the black hole spin axis near the black hole.
NASA's Fermi Satellite Celebrates 10 Years of Discoveries
On June 11, NASA's Fermi Gamma-ray Space Telescope celebrates a decade of using gamma rays, the highest-energy form of light in the cosmos, to study black holes, neutron stars, and other extreme cosmic objects and events.
Fermi's main instrument, the Large Area Telescope (LAT), has observed more than 5,000 individual gamma-ray sources.
In 1949, Enrico Fermi -- an Italian-American pioneer in high-energy physics and Nobel laureate for whom the mission was named -- suggested that cosmic rays, particles traveling at nearly the speed of light, could be propelled by supernova shock waves. In 2013, Fermi's LAT used gamma rays to prove these stellar remnants are at least one source of the speedy particles.
Fermi's all-sky map, produced by the LAT, has revealed two massive structures extending above and below the plane of the Milky Way. These two "bubbles" span 50,000 light-years and were probably produced by the supermassive black hole at the center of the galaxy only a few million years ago.
The Gamma-ray Burst Monitor (GBM), Fermi's secondary instrument, can see the entire sky at any instant, except the portion blocked by Earth. The satellite has observed over 2,300 gamma-ray bursts, the most luminous events in the universe. Gamma-ray bursts occur when massive stars collapse or neutron stars or black holes merge and drive jets of particles at nearly the speed of light. In those jets, matter travels at different speeds and collides, emitting gamma rays.
On Aug. 17, 2017, Fermi detected a gamma-ray burst from a powerful explosion in the constellation Hydra. At almost the same time, the National Science Foundation's Laser Interferometer Gravitational-wave Observatory detected ripples in space-time from the same event, the merger of two neutron stars. This was the first time light and gravitational waves were detected from the same source. Scientists also used another gamma-ray burst detected by Fermi to confirm Einstein's theory that space-time is smooth and continuous.
Public Lecture | Flares and Fireworks From Black Holes
Dan Wilkins, 2017.
To view more public lectures, click HERE. What is Dark Energy?
Dark energy is a mysterious force that is making our universe expand faster and faster. It constitutes 70% of the universe (the rest is dark matter, 25%, and ordinary matter, just 5%).
Scientists study dark energy by looking at how the distribution of galaxies changes as we look farther out into the universe, which is the same as looking farther back in time. This is done in deep astronomical surveys that photograph large portions of the sky in unparalleled detail. SLAC is building a 3.2-gigapixel camera for the next major galaxy survey, the Legacy Survey of Space and Time (LSST).
Vera Rubin, Giant of Astronomy
The Legacy Survey of Space and Time (LSST, previously known as the Large Synoptic Survey Telescope) will be named for an influential astronomer who left the field better than she found it.
To learn more click HERE.
Public Lecture | Brown Dwarfs: Failed Stars or Overachieving Planets?
Eric Nielsen, 2019
To view more public lectures click HERE. The LSST ComCam Shipped
A miniature camera for the Legacy Survey of Space and Time will help test the observatory and take first images.
The LSST Camera
Ranked as the top ground-based national priority for the field for the current decade, LSST is currently under construction in Chile. The U.S. Department of Energy’s SLAC National Accelerator Laboratory is leading the construction of the LSST camera – the largest digital camera ever built for astronomy. SLAC Professor Steven M. Kahn is the overall Director of the LSST project, and SLAC personnel are also participating in the data management. The National Science Foundation is the lead agency for construction of the LSST. Additional financial support comes from the Department of Energy and private funding raised by the LSST Corporation.
The Vera C. Rubin Observatory will survey the entire visible Southern sky every few days over the course of a decade from the top of Cerro Pachόn in Chile.
This survey, known as the Legacy Survey of Space and Time (LSST. Previously known as the Large Synoptic Space Telescope), will give us the widest, fastest and deepest view of the night sky ever observed.
Displaying just one of its full-sky images would require 1,500 high-definition TV screens.
In over 10 years of operation, the LSST will detect tens of billions of objects.
It will be the first time that a telescope will catalog more galaxies than there are people on Earth.
LSST data will be available to both scientists and the general public to broaden public participation in science and enhance education in STEM – science, technology, engineering and mathematics.
These image highlight some of the recent contributions KIPAC scientists have made to a deeper understanding of our universe and our place within it.
SPEAR, the Stanford Positron Electron Asymmetric Ring, opened in 1972 as an exciting new facility for particle physics. Rather than crashing subatomic particles into a stationary target, it would smash two beams of particles into each other head-on, releasing twice as much energy and making the discovery of much more massive particles possible. Among the many high-energy physics experiments conducted in the ring, two earned Nobel Prizes – one for the discovery of the J/psi particle, the other for the discovery of the tau lepton.
When charged particles race along a curved path like the one in SPEAR, they emit what’s known as synchrotron radiation in the form of light. This was considered a nuisance at first. But researchers soon realized that it could be channeled into beams of X-ray light for a wide range of experiments.
In 1973, a group of Stanford scientists persuaded the particle physicists who were in charge of SPEAR to let them divert an X-ray beam into a makeshift experimental station – a Sears garden shed – tacked onto the side of the ring, and the Stanford Synchrotron Radiation Project was born. This beam was about 100,000 times more intense than those generated by X-ray tubes, allowing scientists to probe the atomic and molecular structure of matter and do experiments that would revolutionize fields like biology and medicine.
SPEAR was the first large X-ray light source to welcome scientists from around the world to use its X-ray beams for experiments. In 1990, when it was no longer needed for particle physics experiments, it was fully dedicated to this work. Today it’s the heart of the Stanford Synchrotron Radiation Lightsource (SSRL), whose powerful beams of X-ray and ultraviolet light are used by more than 1,500 experimenters from all over the world each year. SPEAR is probably the most useful high energy physics machine per dollar of cost ever built, and it’s still driving world-class science.
X-ray Laser Animated Fly-through
Take a tour with an electron's-eye-view through SLAC's revolutionary new X-ray laser facility with this 5 1/2 minute animation. See how the X-ray pulses are generated using the world's longest linear accelerator along with unique arrays of machinery specially designed for this one-of-a-kind tool.
For more than 40 years, SLAC's two-mile-long linear accelerator (or linac) linac has produced high-energy electrons for cutting-edge physics experiments. In 2009 SLAC's linac entered a new phase of its career with the creation of the Linac Coherent Light Source (LCLS).
LCLS produces pulses of X-rays more than a billion times brighter than the most powerful existing sources, the so-called synchrotron sources which are also based on large electron accelerators.
The ultrafast X-ray pulses are used much like flashes from a high-speed strobe light, enabling scientists to take stop-motion pictures of atoms and molecules in motion, shedding light on the fundamental processes of chemistry, technology, and life itself.
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Construction of the LSST Camera began in 2015 in a clean room at SLAC. The size of a small car and weighing more than 3 tons, the 3.2-gigapixel camera will be the largest digital camera ever built for ground-based optical astronomy. Displaying just one of its full-sky images would require more than 1,500 high-definition TV screens.
SLAC's astrophysics and cosmology research is led by the joint SLAC-Stanford Kavli Institute for Particle Astrophysics and Cosmology. KIPAC serves as a bridge between the disciplines of astrophysics, cosmology and particle physics, with special emphasis on cosmic structure, dark energy, dark matter, the early universe, compact objects and natural particle accelerators. Its mission is to bring the resources of modern computational, experimental, observational and theoretical science to bear on our understanding of the universe at large.
Did you know? Our 2-mile-long Klystron Gallery extends beyond the vanishing point of the human eye – you can only see two-thirds of the way down its length!
At the Kavli Institute, Stanford physicists aim to unlock the deepest secrets of our universe.
The Kavli Institute for Particle Astrophysics and Cosmology, or KIPAC, was inaugurated in 2003 as an independent laboratory of Stanford University to serve as a bridge between the disciplines of astrophysics, cosmology and particle physics. KIPAC's members work in the Physics and Applied Physics Departments on the Stanford campus and at the SLAC National Accelerator Laboratory. Its mission is to bring the resources of modern computational, experimental, observational and theoretical science to bear on our understanding of the universe at large. We are a broad community of close to 200 people with diverse interests in astrophysics and cosmology. Our efforts are organized as the Kavli Institute for Particle Astrophysics and Cosmology, or KIPAC, an independent laboratory of Stanford University. Initiated with a generous grant from Fred Kavli and The Kavli Foundation, KIPAC is housed at the SLAC National Accelerator Laboratory and in the Varian Physics and Physics & Astrophysics buildings on the Stanford campus. The lab is funded in part by Stanford University and the United States Department of Energy.
The accelerator structure is made from over 80,000 copper disks and cylinders. It accelerates electrons to 669,600,000 mph – 99.9999999 percent of the speed of light.
The large aluminum pipe is the alignment system, an adjustable platform that uses a laser to ensure the accelerator tube is perfectly straight.