Research here probes the fine structure of matter, from the protons, neutrons, quarks and gluons in the atom's nucleus to the electrons that bind to nuclei to make atoms. This work relies on the lab's world-leading superconducting radiofrequency (SRF) technology, which powers its accelerator, the Continuous Electron Beam Accelerator Facility (CEBAF). Jefferson Lab also leads development of the High Performance Data Facility, a new data-intensive computing capability built with Lawrence Berkeley National Laboratory, and is partnering with Brookhaven National Laboratory to design and build the Electron-Ion Collider — a next-generation machine that will deepen our understanding of how quarks and gluons build the visible universe.
U.S. Department of Energy provides initial funding for CEBAF research, development and design.
Scientists interested in conducting research once the facility is operational form the CEBAF Users Group. CEBAF's User community includes scientists, researchers, engineers, teachers and students. The group strives to: • encourage and assist scientists and engineers in the use of CEBAF. • create and maintain effective communication channels for the exchange of information between the CEBAF staff and others interested in using CEBAF. • engage effective methods of offering counsel to the CEBAF management on policy affecting facility development and utilization. • promote effective use of CEBAF for the benefit of society. To obtain experiment time at CEBAF, researchers submit proposals outlining the type of experiment they wish to perform and the estimated number of "beam hours" they will need. Proposals are reviewed and graded by the Program Advisory Committee (PAC), a committee of physics experts from universities and laboratories worldwide.
Hermann Grunder assumes the lab's first directorship.
CEBAF adopts superconducting radiofrequency (SRF) particle accelerating technology.
Construction begins on the Continuous Electron Beam Accelerator Facility, known as CEBAF.
First successful tests of a cryounit, a section of accelerator containing two superconducting radiofrequency accelerator cavities, demonstrate feasibility of SRF in CEBAF. This image shows two SRF particle accelerator cavities assembled together. These are the innermost parts of a cryounit. Once fully assembled, a cryounit resembles one quarter of a full cryomodule.
DOE awards management and operating contract to the Southeastern Universities Research Association, the original contractor that won the bid for building the new lab.
Workers install Gray Ghost II. Each modular section of the CEBAF accelerator is called a cryomodule. Gray Ghost II was the first production cryomodule to be installed in the CEBAF tunnel. It was installed in the injector, which is the first section of the machine, for testing. Following testing, the cryomodule was removed and cut up again for parts.
The CEBAF Injector, the source of electrons for the accelerator, reaches full design energy, accelerating an electron beam to 45 mega-electron volts (MeV). In its original design, the CEBAF injector began with a 100 kV thermionic gun. Various components shape individual bunches of electrons generated by the gun into the beam that will be accelerated as the electrons travel through the machine. A five cell graded beta capture section is used to accelerate the beam to 500 keV for injection into the first superconducting cavities. A two-cavity cryounit accelerates the beam to a nominal 5 MeV. Following a long drift section, the beam enters two standard cryomodules for acceleration to 45 MeV.
CEBAF receives its first patent, for a cryogenic liquid-level measuring apparatus.
Workers install Golden Girl, the final cryomodule needed to complete CEBAF. The last section of newly built accelerator was installed in the Continuous Electron Beam Accelerator Facility, marking completion of the first large-scale superconducting radiofrequency particle accelerator in the world. The "Golden Girl" cryomodule was signed and wreathed by staff members before its procession to the CEBAF underground tunnel for installation. The cryomodule was named for the administrative assistants for the departments who had constructed CEBAF, in honor of their contributions to the project.
First time liquid helium coolant in CEBAF becomes superfluid, allowing for stable operation of the electron beam. The milestone coincides with celebrations of the 50th anniversay of D-Day. Helium in CEBAF remains superfluid until Hurricane Isabel takes the Central Helium Liquefier down in 2003.
The first electron beam is delivered to an experimental hall (Hall C), marking the beginning of operations of the first large installation of superconducting radiofrequency (SRF) particle accelerating technology. A few weeks later, on July 24, the first electron beam was delivered on an experimental target in Hall C.
CEBAF delivers its first electrons to an experimental target, which was placed in Experimental Hall C.
A polarized gun delivers the lab’s first polarized electron beam. Polarization means the spinning particles in the beam are mostly aligned in the same direction.
The CEBAF accelerator reaches design energy of 4 giga-electron volts. More milestones follow: CEBAF accomplishes design energy in pulse mode on May 10; 4 GeV pulses are delivered to target in Hall C on May 26; and on Nov. 4, the accelerator achieves full design goal with a stable, five-pass 100 kW continuous 4 GeV beam delivered to Hall C.
CEBAF, NASA and Digiray Corp. are awarded the R&D 100 Award for work on the reverse geometry x-ray miniprobe. The transportable system for realtime x-ray imaging is being used to find cracks and corrosion in oil refinery piping. It can locate and measure very small features anywhere on or within the object being examined.The system is used to find cracks and corrosion in oil refinery piping. The RGM relies on reverse geometry, which changes the relationship of the x-ray source to the object being x-rayed and eliminates the need for precise alignment. The views delivered are sent directly from detector to computer.
The first physics experiment – “The Energy Dependence of Nucleon Propagation in Nuclei as Measured in the (e, e'p) Reaction” – begins taking production data in Hall C.
The Applied Research Center (ARC) breaks ground. The facility will be home to scientists from universities, the lab, and a host of other agencies and businesses.
CEBAF changes its name to the Thomas Jefferson National Accelerator Facility, less formally known as Jefferson Lab. Energy Secretary Hazel O'Leary, 1993-1997, presided over the ceremonies.
Construction begins on the Free-Electron Laser, the world’s highest-power tunable infrared laser, which uses electrons to produce laser light.
Dilon Technologies licenses Jefferson Lab detector technology for medical imaging for diagnostics and research purposes, including detection of cancers in the breast, thyroid, brain and prostate.
Hall B begins taking data with the CEBAF Large Acceptance Spectrometer. This detector is unique in that it has a very large acceptance; in other words, nuclear physicists can measure the momentum and angles of almost all of the particles produced in electon-proton or real photon-proton ollisions. Roughly spherical, the detector measures 30 feet across. It completely surrounds the target, which is typically a small vial of liquid hydrogen (hydrogen's nucleus is comprised of a single proton) or deuterium (with a nucleus consisting of a neutron and a proton). The CLAS detector is built like an onion, with successive layers of different types of particle detectors. As the particles that fly out of the target enter the detector, their paths are bent by the detector's magnet. The particles first enter devices called wire chambers that measure the particles' curved paths to determine their momenta. Next, a layer of detectors measure the time of arrival of a particle to determine its speed. From the measured momentum and speed of the particle, physicists can determine its mass and thus, its identity.
Vice President Al Gore awards the Directives Review Team the Vice President’s Hammer Award for the simplification of Environment, Health and Safety requirements, a contribution in support of President Clinton’s National Performance Review.
Hall A begins taking data for its first experiment. The hall’s dual High Resolution Spectrometers act like huge microscopes, allowing scientists to “see” inside an atom.
The first polarized electron beam is used for an experiment in Hall A -- 30 microamps at 35 percent polarization.
A Jefferson Lab theorist publishes a seminal paper on generalized parton distributions, or GPDs, a new framework for studying proton structure. GPDs are a set of mathematical functions that allow physicists to, for the first time, obtain a 3-dimensional snapshot of the inner structure of the particles that make up the atom's nucleus. This work gives scientists a glimpse of the structure and dynamics of the basic building blocks of matter.
The Free Electron Laser achieves first light at 155 watts — 28 times the existing power record.
The lab achieves five-pass, four-GeV, three-beam separation to all three experimental halls.
The Commonwealth of Virginia and Science Museum of Virginia name Lab Director Hermann A. Grunder the Outstanding Scientist of the Year.
Installation of second polarized electron gun boosts lab's physics program.
Infrared Demo Free-Electron Laser surpasses 1 kW design goal to achieve 1.72 kW. The FEL project was funded by the Department of the Navy, the Department of Energy, and the Commonwealth of Virginia, and was supported by industries, universities and the City of Newport News.
A central goal of nuclear physics is understanding matter in terms of the proton’s building blocks, quarks and gluons, and that starts with mapping the inside of the proton. Its elastic electromagnetic form factors describe how charge and current are distributed within it — quantities physicists have chased for five decades. Three Jefferson Lab experiments reshaped the picture by measuring the proton's electric-to-magnetic form factor ratio. The ratio falls as the electron strikes the proton harder, showing that charge extends over a wider region than magnetization — the first definitive evidence the two differ.
Jefferson Lab receives a $35M contract to engineer and assemble the superconducting accelerator and to design and oversee installation of the helium refrigeration plant for the Spallation Neutron Source (SNS) for the Oak Ridge National Lab
The deuteron — one proton bound to one neutron — is the simplest composite nucleus. Its shape comes largely from the exchange of particles called pions, which pull it away from a simple spherical form. Firing high-energy electrons at deuterons lets physicists probe the interior at very short distances. Two Jefferson Lab experiments in the late 1990s pushed these measurements further than any before. Combining their results produced the first map of how electric charge is distributed inside the deuteron, including the point where that distribution crosses zero — a demanding test of models of the force binding protons and neutrons together.
CEBAF reaches enhanced design energy of 6.07 GeV. Originally designed as a 4 GeV machine, this accomplishment demonstrates it is capable of delivering more than 50% higher energy electron beams. The feat is made possible by skilled operators and accelerator experts and their collective experience in running the machine, as well as the incredible efficiency of the SRF particle accelerating technology. The milestone also opens the door for future upgrades of the machine.
Jefferson Lab data demonstrate that the reaction for producing a well-known particle called the Delta is not described by perturbative QCD calculations, or calculations of the theory of Quantum Chromodynamics, which describes subatomic particles and their interactions. The experiment studied the electroproduction of the Delta(1232) resonance at the highest four-momentum transfers for which exclusive resonance electroproduction has ever been observed. The Delta(1232) is an "excited state" of the proton, and it can be thought of as a proton with extra energy.
Pre-conceptual design report published on project to upgrade the energy of the CEBAF accelerator to 12 GeV and to build a fourth experimental hall.
Infrared Demo Free-Electron Laser achieves top output of 2.1 kW, more than double the original design goal
SURA names Christoph W. Leemann as Jefferson Lab's second director. Leemann had served previously as Jefferson Lab's deputy director as well as its associate director for accelerators and a leader of the management team responsible for the successful design and construction of the $600 million high-tech DOE facility. Leemann came to Jefferson Lab in 1985 from Lawrence Berkeley National Laboratory where he had been involved in the design and construction of high-energy accelerators since 1970.
Jefferson Lab Free-Electron Laser generates terahertz levels 20,000 times brighter than anyone else. The feat ushers in a new era of imaging.
The lab installs its first high-performance computer cluster, 2m, in support of Lattice Quantum Chromodynamics (QCD), the numerical approach to solving the fundamental theory of quarks and gluons and their interactions. The cluster contains 128 nodes of single processor 2.0 GHz Xeons connected by a Myrinet network. It achieves 1/8 TeraFlops of performance (Linpack), contains 65 GBytes of total physical memory, and delivers 270MB/s simultaneous node-to-node aggregate network bandwidth.
The Spallation Neutron Source at DOE's Oak Ridge National Laboratory receives the first Jefferson Lab-designed and built cryomodule, a modular section of the new particle accelerator being built to power the machine.
Precise data on neutron and proton form factors are important for understanding how these particles are formed, as well as the electromagnetic properties of nuclei. This experiment makes a first determination of the neutron charge form factor, a groundbreaking measurement that reveals the distribution of electric charge inside the neutron.
Dirk Walecka, College of William & Mary physics professor and the first scientific director of CEBAF, is named Virginia's Life Achievement in Science recipient.
Jefferson Lab conducts a novel experiment with the Continuous Electron Beam Accelerator Facility (CEBAF) accelerator to determine the feasibility and effectiveness of energy-recovery technology in the form of energy-recovering linear accelerators (energy-recovery linacs or ERLs), which could lead to the development of a new class of particle accelerators. In the experiment, electrons are looped back through a linac out of phase, where they are decelerated as they return their energy back to the radiofrequency cavities to power the next batch of new electrons. Technicians installed a series of four magnets designed to provide the slight phase delay, as well as the stands to accommodate them. A relatively small beam-extraction device, known as a “beam dump” was also built, so that the electron beam can be “parked” and examined once each phase is complete. In addition, dedicated optics for beam transport, instrumentation and vacuum chambers (the pipe that carries the beam) were installed or readied for the experiment.
The 2003 computer cluster is built with 256 processors of 2.67 GHz Intel Xeon processors, achieving .4 Teraflop-level performance for lattice quantum chromodynamics calculations.
Jefferson Lab scientists complete 100th experiment with CEBAF
Jefferson Lab's 12 GeV Upgrade achieves Critical Decision-Zero (CD-0), a DOE designation that recognizes the "mission need" for the Upgrade and allows the lab to develop conceptual, acquisition and project execution plans
Anatoly Radyushkin, a jointly appointed physics professor at Old Dominion University and senior scientist at Jefferson Lab, is named a Virginia Outstanding Scientist
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