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Title: CEBAF at Jefferson Lab


The U.S. and international nuclear physics community uses Jefferson Lab's state-of-the-art Continuous Electron Beam Accelerator Facility or CEBAF to conduct world-class fundamental research. The Lab supports more than 1,250 visiting researchers from more than 200 institutions.

Publication Date:
Research Org.:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
Country of Publication:
United States

Citation Formats

None. CEBAF at Jefferson Lab. United States: N. p., 2015. Web.
None. CEBAF at Jefferson Lab. United States.
None. 2015. "CEBAF at Jefferson Lab". United States. doi:.
title = {CEBAF at Jefferson Lab},
author = {None},
abstractNote = {The U.S. and international nuclear physics community uses Jefferson Lab's state-of-the-art Continuous Electron Beam Accelerator Facility or CEBAF to conduct world-class fundamental research. The Lab supports more than 1,250 visiting researchers from more than 200 institutions.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2015,
month = 1
  • By 1997, this facility will collect over 1 Terabyte of raw information/day accelerator operation from three concurrently operating experimental halls. With post-processing, it means that about 250 TB raw and formatted experimental data will be generated each year. By the year 2000, a total of one Petabyte will be stored on-line. Critical to the program is the networking and computational capability to collect, store, retrieve, and reconstruct data on this scale. Design criteria include support of a raw data stream of 10-12 MB/second from Experimental Hall B, which will operate the CEBAF Large Acceptance Spectrometer. Keeping up with this datamore » stream implies design strategies that provide storage guarantees during accelerator operation, minimize the number of times data is buffered, allow seamless access to specific data sets for the researcher, synchronize data retrievals with scheduling of postprocessing calculations on the data reconstruction CPU farms, as well as support the site capability for data reconstruction and reduction at same overall rate that new data is being collected. Current implementation uses state of the art StorageTek Redwood tape drives and robotics library integrated with the Open Storage Manager Hierarchical Storage Management software (Computer Associates, International), the use of Fibre Channel RAID disks dual-ported between Sun Microsystems SMP servers, and a network-based interface to a 10,000 SPECint92 data processing CPU farm. Issues of efficiency, scaleability, and manageability will become critical to meet the year 2000 requirements for a Petabyte of near-line storage interfaced to over 30,000 SPECint92 of data processing power.« less
  • This paper presents interim conceptual plans for upgrading the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility to extend Jefferson Lab's world leadership in nuclear physics research. The CEBAF accelerator was designed in the mid-1980's to provide beams of electrons at an energy of 4 GeV (billion electron volts) for use as probes of the atom's nucleus in CEBAF's three experiment halls. As of early 1999, the accelerator exceeds its design energy by routinely operating above 5.5 GeV. When upgraded, it will provide 11 GeV electron beams for studies in existing experimental halls and 12more » GeV electrons to generate photon beams for related but qualitatively different nuclear studies in a new Hall D.« less
  • The Jefferson Lab nuclear physics accelerator, CEBAF, continues to reliably deliver polarized CW electron beams with energy in the range of 1--5.5 GeV. The 330 installed 1,500 MHz SRF cavity systems perform solidly, contributing a small fraction of the machine downtime. The 5-pass energy capability has been pushed to near 6 GeV by application of in situ helium processing to almost all of the cavities. New operational tools have been developed and deployed which allow the operators to quickly reconfigure the linacs for optimal performance under various energy and beamloading conditions. Plans are being developed for upgrading CEBAF to 12more » GeV. This requires a new cryomodule design and use of 5.5 recirculations for the top energy. Subsystem development is underway on a 7-cell cavity, new zero-backlash tuner, improved magnetic shielding, and an arc-free waveguide rf feed, as well as a new cryomodule mechanical system. Significant facility changes have been made in preparation for this work. A new rf control system will also be required. In addition to the successful nuclear physics program, the JLab FEL produced a world-record 1.7 kW CW in the infrared. An upgrade program is ready to begin. Significant efforts have also been directed in support of APT and RIA, as well as collaborations related to cavity fabrication and processing techniques.« less
  • The excited baryons made from light quarks are known to decay in single meson as well as in multimeson final states. In particular, the double pion production is sensitive to many excited states of proton and neutron. Quark models predict such decays and also that some resonances could decouple from single meson channels and appear predominantly in multipion production reactions via electromagnetic excitation: the so called ''missing resonances''. These issues are part of the CLAS collaboration scientific program at Jefferson Laboratory, where the reaction eN -> e'N(pi)(pi) is being used in the mass region between threshold and 2.2 GeV tomore » investigate baryon resonances and test quark models. In this contribution I will present a framework for the physical interpretation of the data, especially focusing on the approach developed by the Genova-Moscow collaboration. Some very preliminary raw mass distributions collected with CLAS are then shown.« less
  • The Jefferson Laboratory's superconducting radiofrequency (srf) Continuous Electron Beam Accelerator Facility (CEBAF) provides multi-GeV continuous-wave (cw) beams for experiments at the nuclear and particle physics interface. CEBAF comprises two antiparallel linacs linked by nine recirculation beam lines for up to five passes. By the early 1990s, accelerator installation was proceeding in parallel with commissioning. By the mid-1990s, CEBAF was providing simultaneous beams at different but correlated energies up to 4 GeV to three experimental halls. By 2000, with srf development having raised the average cavity gradient up to 7.5 MV/m, energies up to nearly 6 GeV were routine, at 1-150more » muA for two halls and 1-100 nA for the other. Also routine are beams of >75% polarization. Physics results have led to new questions about the quark structure of nuclei, and therefore to user demand for a planned 12 GeV upgrade. CEBAF's enabling srf technology is also being applied in other projects.« less