Jefferson Lab Weekly Briefs December 9, 2009
Jefferson Lab Weekly Briefs
December 9, 2009
12 GeV Upgrade
Five superconducting spectrometer magnets and several large items of supporting infrastructure are needed for the new Super High Momentum Spectrometer (SHMS) in Hall C, with all of these items having multi-year fabrication times. The Q1 quadrupole magnet construction is in progress at the vendor. The remaining four magnets are in various stages of the procurement process. The vendor selection for the cryogenic control-reservoirs is nearly complete, and bids from several qualified vendors for the five large magnet power supplies are under evaluation. A detailed layout for shielding materials for the detectors’ Shield House is being developed and also is being incorporated into engineering drawings. Procuring the detailed drawing package is the last major step in advance of manufacture of the Shield House and Support Structure for the SHMS.
Monday Deadline for PAC Proposals
Confessions of a Converted Lecturer
JSA/JLab Graduate Fellowship Program
JSA/JLab Sabbatical Support Program
The accelerator ran well with high current (115 μA) to Hall A. On Dec. 1, the injector was set up to deliver beam with vertical polarization. Hall B was changed from pass 5 to pass 1. On Wednesday, after backing out the injector setup for the vertical polarization, Hall B was changed back to pass 5 and a spin dance was performed. On Friday, the position indicator of the vacuum valve at 1L06A failed and the faulty part was replaced.
FEL staff set up for additional tests of the grating optics this week. All of the instrumentation and mechanicals are working properly in the ultraviolet optical can that was installed two weeks ago. FEL staff continued work on the JLAMP Proposal, and a plan was established to replace the FL03 cryomodule with one that generates up to 55 MeV in January.
The important role of two-photon exchange (TPE) in electron-proton scattering has been revealed in a number of studies over recent years. In a new paper <arXiv:0911.3619 [nucl-th]>, the effects of TPE on the electromagnetic form factor of the pion have been computed, taking into account the finite size of the pion. Compared to the soft-photon approximation for the infrared divergent contribution, which neglects hadron structure effects, the corrections are found to be <1 percent for small Q2 (Q2<0.1 GeV2), but increase to several percent for Q2>1 GeV2 at very backward angles.
JLab's Safety Numbers
20 Days since Last Recordable Accident (JLab record: 331)
JLab Calendar of Events
Dec. 9: Science Series Lecture: Visualizations and Visual Illusions
Environment, Safety, Health & Quality
The following ES&H Manual Chapter and its associate appendices have been revised and are available for use:
End-of-Year Radiation Badge Change Out
JSA Initiatives Fund Projects Announced
Last Week for Key Validation
Door and Cubicle Decorating Contest
Quark Cafe Hosts Holiday Bake Sale on Dec. 17
Quark Cafe Holiday Pie Orders Taken Through Dec. 18
JAG Offers JLab Merchandise Through Online Store