Jefferson Lab Weekly Briefs August 6, 2008


Jefferson Lab Weekly Briefs
August 6, 2008

12 GeV Upgrade

The R&D task to re-measure the Higher-Order Mode (HOM) damping in the 12 GeV-style superconducting radio frequency (SRF) cavities had previously confirmed last year’s results that the damping meets the specification comfortably. Subsequently, measurements in the Vertical Test Area (VTA) have confirmed that VTA measurements can be used as a step in the overall quality assurance program to identify cavities that have marginal damping behavior prior to cryomodule assembly.  

Measurements of both prototype beamline quadrupoles is underway. Initial analysis of the data found that the fields are as expected. Fine tuning of the assembly and fabrication processes will be done based on the results of the measurement.

Requests For Proposals (RFPs) were released for the 4.5 Kelvin Coldbox, klystron and SRF cavity contracts. These represent roughly half of the total contract value of the FY09 procurements for Accelerator Systems.


The repair contract for Transformer LN1 has been awarded. LN1 will be removed by a crane and shipped to the repair company. In the injector, Gun 3 was charged to 125 kilovolts (kV) for high-voltage processing, and the Gun 2 bakeout was completed. Box supply water flow and trip levels now available on EPICs and box supply maintenance continued on the dogleg magnets. The South Linac was brought to high voltage without major problems. The General Purpose Building was tied in to the electrical system, and tunnel safety training was completed.

Free-Electron Laser (FEL)

The FEL staff is making good progress with installing beamline for the ultraviolet (UV) system. On the gun test stand, a new cathode was made after mildly baking the system to reduce water; a quantum efficiency of 16 percent was achieved. The 3rd Optical Transfer System Turning Mirror Cassette for the infrared (IR) line was hung on the ceiling, and the FEL gun is nearing final assembly.

Theory Center

In a Theory Center paper (arXiv:0807.0944v1 [hep-ph]) last month, the up and down quark contributions to the proton magnetic form factor at finite momentum transfer were determined by applying chiral corrections to quenched lattice data. Combined with the experimental values of the proton and neutron magnetic form factors, a relatively accurate value for the strange magnetic form factor was obtained, i.e. GsM= -0.034 ± 0.021 in units of the nuclear magneton. This result is in excellent agreement with the recent determination of GsM at Mainz.

JLab's Safety Numbers

296 Days since Last Recordable Accident (JLab record: 319)
641 Days since Last Lost Workday Accident (JLab record: 641)

JLab Calendar of Events

Aug. 12-14 Occupational Medicine Cholesterol Screenings
Aug. 12-14: DOE Accelerator Safety Workshop
Aug. 17-19: Lead Radius Experiment (PREX) Workshop
Aug. 22: Christoph W. Leemann Retirement Reception
Sept. 1: Labor Day holiday: JLab closed

Environment, Safety, Health & Quality

A rattlesnake was recently sighted during a contractor walkthrough on the north end of the property bordering Canon Boulevard. This section of the site is currently in a natural state, but it will be used during construction of the Hall D complex. There were no interactions with the snake and no one was injured.

It's always a good idea to wear boots and long pants in wooded areas. Also, if you sight a snake, give it a wide berth. Eighty percent of snake bites occur when people are trying to kill the animal, so the most prudent action is to distance yourself from the threat right away.

If you are bitten, the best course of action is to get to an emergency room as soon as possible; remain calm and keep the injured area lower than the heart. If possible, information on the snake's marking and appearance should be noted.

Computing and Networking Infrastructure (CNI)

The CNI group is planning a systems maintenance period from 5-10 p.m. on Tuesday, Aug. 12. Currently, the only planned outage is a configuration outage to the bbftp server, a scientific computing parallel ftp server.

Other maintenance should be non-intrusive, however, new security patches will be pushed out to all Linux and Windows systems. If you work on one of these systems, please log out of all desktop computers at the end of your workday Aug. 12, but leave the systems powered on overnight so that the patches can be installed. If you experience difficulties with your computer, reboot to see if that fixes the problem before calling the Help Desk (x7155) for assistance.


Cholesterol Screenings Offered Aug. 12-14
Cholesterol Screenings will be held August 12-14. Anyone interested should call Occupational Medicine at x7539 to schedule an appointment. If you have received this test within the last year, this includes medical monitoring, Occupational Medicine asks that you let others take advantage of this opportunity.

Instructions for All International Visitors to Jefferson Lab
Federal Laws and Jefferson Lab’s contract with the U.S. Department of Energy requires the laboratory to follow certain rules with respect to non-U.S. citizen’s access to Jefferson Lab. These rules have been compiled for your convenience in this document.

Christoph Leemann Retirement Reception
An open house celebrating JLab Director Christoph Leemann's retirement will be held Aug. 22 from 3-4:30 p.m. in CEBAF Center. Cake and punch will be served. So please drop by to say goodbye. An electronic guestbook also has been created, where staff, users and others can leave a comment or best wishes for Christoph.

Property Management Reminder: Removing Property
The Property Office reminds property custodians of the requirements regarding removal of JLab property from the site. JLab property may only be removed from the lab for official business only. This applies to both tagged and untagged items.
The following are required to move property offsite:

  1. The removal or shipping of any property requires prior approval of Property Management Office.
  2. If the property shipped is associated with a purchase order (warranty return, Lab property furnished to subcontractor, etc.), Shipping & Receiving and the Property Management Office must coordinate with the Procurement Office.
  3. Property subject to the technology transfer rules found in Section 3.18, "Technology Transfer," also requires authorization by the Chief Financial Officer or his designee.

An Employee Property Pass or loan agreement with another institution is required from the JLab Property Office before property is removed from the lab. While offsite, the safe keeping of the property is the responsibility of the employee or institution having temporary custody. For more information, consult the JLab Property Manual.

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