CEBAF Accelerator Achievements

Technical supplement to “Polarization transfer observables in elastic electron-proton scattering at Q2=2.5,5.2,6.<

“…In both experiments, the polarized electron beam of Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) [5,6] was scattered from a liquid hydrogen target in experimental Hall C. Elastically scattered electrons were detected in a large-acceptance electromagnetic calorimeter called "BigCal" in coincidence with elastically scattered protons detected by the Hall C High Momentum Spectrometer (HMS), equipped with a double focal plane polarimeter (FPP) to measure the polarization of the recoiling protons. The decoding of the raw data is described in Ref.…”

“…The maximum χ 2 imposed on drift-based track candidates was chosen to be as small as possible without artificially reducing the efficiency to 5 Because the FPP chamber wire spacing was twice that of the HMS chambers and both sets of chambers used the same gas mixture and operated in a similar high-voltage regime, the drift time window for useful hits for FPP tracking was roughly twice as wide as that for HMS tracking. 6 The reasons for the preferential treatment of six-plane tracks on the first iteration of pattern recognition and track reconstruction are that (a) the selection of hits and tracks based on χ 2 strongly favors five-plane tracks over six-plane tracks due to the small number of degrees of freedom (only 1(2) for tracks with 5(6) hits), and (b) the greater ambiguity in the determination of the correct left-right combination of the hits in the case of five-plane tracks. Events with five-plane tracks reconstructed in the FPP were nonetheless retained in the final analysis to minimize ϕ-dependent variations of tracking efficiency.…”

Search for New and Unusual Strangeonia using CLAS

“…The lab's primary mission is to conduct basic research of the atomic nucleus using the lab's unique particle accelerator, known as the Continuous Electron Beam Accelerator Facility (CEBAF) [29] [30] [31]. Jefferson Lab also conducts a variety of research using its Free-Electron Laser (FEL), which is based on the same electron-accelerating technology used in CEBAF.…”

The JLab TMD Program at 6 GeV and 11 GeV

“…At the end of 6 GeV operations in 2012, CEBAF routinely delivered high dutycycle electron beams with energy up to 6 GeV, polarization up to 90% and continuous-wave beam currents of up to 180 µA to three different experimental halls [6,7]. In this document, I give an overview of published and forthcoming SIDIS results from the 6 GeV era of CEBAF operations and an overview of the planned SIDIS program using the upgraded CEBAF beam.…”