JLab Weekly
Briefs
is an ongoing publication providing information on the status of
safety, accelerator operations, experiments, free-electron laser,
reviews, upcoming activities and special events. Deadline for
submission is every Tuesday by 10 a.m. Submit new items to: Public Affairs or contact Kandice
Carter at x7263.
Archives
|
|
Jefferson Lab Weekly Briefs
November 4, 2009
12 GeV Upgrade
Procurement activities continue as the focus of the 12 GeV accelerator
team, with more than $22 million of awarded contracts and an additional
$7 million in the procurement process. During the past month, meetings
were held with the vendors of the 4.5 K coldbox for the new Central
Helium Liquefier and the septa magnets for the beam transport system.
Audits were carried out of the quality assurance/quality control
programs of some potential vendors; reports are pending. Detailed
planning is underway for installation work during the January and July
accelerator downs in 2010. The final pre-construction design and safety
review for the magnet power subsystem was held.
Physics
In Hall A, production data taking for experiment E05-109, HAPPEx-III, a
measurement of the nucleon strange form factors at high Q2, was
interrupted on Tuesday, Oct. 20, by a sitewide power outage. Recovery
from the damage this caused was so extensive that it was decided to end
the experiment on Oct. 28, one day earlier than scheduled, after all
essential calibration data had been taken. In the end, HAPPEx-III
succeeded in obtaining nearly 70 percent of the production data that
had been planned.
In Hall C, the hypernuclear experiment E05-115 in Hall C has been
completed, coming close to obtaining all the proposed data. Production
data was taken with lithium-7, beryllium-9, boron-10 and chromium-52
targets. In addition, calibration data was taken with water,
polyethylene and carbon targets. The hall is now removing the High
Resolution Kaon Spectrometer experiment and starting the installation
of the Q-weak parity experiment, scheduled to start commissioning in
May.
Accelerator
The accelerator site lost power again around 12:30 a.m. Tuesday, Oct.
27. The power outage was most likely due to some faulty parts in the
power line feeding into the lab. Dominion replaced the faulty parts.
Beam delivery was resumed at the end of Wednesday’s owl shift. On
Wednesday afternoon, the injector and Hall B were taken down to
controlled access briefly for a tour. On Sunday, Hall B was changed
from 1-pass to 5- pass beam. The accelerator energy change to 6.068 GeV
began Monday.
Free-Electron Laser
This week saw the achievement of a major milestone in the progress of
the JLab FEL: first beam through the UV beamline after three years of
assembly, installation and checkout. It took less than two hours to
successfully recover beam through that line. This sets the stage for
lasing next spring after installation of the optical systems and
wiggler chamber and diagnostics. The team also put light on a grating
for the ring resonator effort, took terahertz data, measured radiation
backgrounds for a user and took an extensive set of data on injector
halo production and average current limits in the present setup.
Theory Center
Using a new technique recently developed at JLab, a collaboration
between Theory Center staff and experimentalists has extracted the
neutron F2n structure function from inclusive
proton and deuteron data in the large-x
region <arXiv:0910.4920
[hep-ph]>. The data have been used to test the validity of
quark-hadron duality in the neutron and establish for the first time
the accuracy of duality in the low-lying neutron resonance regions over
a range of Q2. The findings open the possibility
of using resonance region data to constrain leading-twist parton
distributions at large x.
|
Computing and Networking Infrastructure
JLab Wireless Access
Changes
On Saturday, Nov. 14, the CNI group will upgrade JLab's wireless
network. This new system will allow the group to expand coverage and
increase security. At this time, you will not need to change how you
connect to the wireless network via 'jlab_secure' or 'jlab_guest'. The
group is adding a new wireless network, called 'jlab', that users may
begin migrating to after the upgrade. The new network will replace
'jlab_secure' on Dec. 7.
Linux Patches To Be Sent
Out Tuesday
The CNI group is planning to push out Redhat Linux patches to all
desktops on Tuesday evening, Nov 17. Plan to reboot your Linux system
sometime on Nov. 18 to complete the patch installation. If you
encounter problems with your system, contact the Helpdesk at x7155.
Announcements
Performance Appraisals
By now, all draft appraisals should have been completed and sent to the
next-level reviewer or calibrator. If you are behind due to system
problems or have questions about how to proceed, contact Bruce Ullman
at x7170 or Cassandra Andrews at x7068.
JLab Veterans Day Salute
on Nov. 11
In recognition of the many people at JLab who have served in the Armed
Forces, the lab will have cake in the CEBAF Center lobby from 11:30
a.m. - 2 p.m. on Wednesday, Nov. 11, for all veterans. Veterans, sign
the board and enjoy a piece of cake!
JLab's Safety Numbers
112 Days since Last Recordable Accident (JLab record:
331)
420 Days since Last Lost Workday Accident (JLab record: 676)
JLab Calendar of Events
Nov. 12: Safety
Shoe
Vendor
onsite
Nov. 16: Women
in Science and Engineering Workshop
Nov. 26-27: Thanksgiving
holidays
-
JLab
closed
Dec. 5: JLab Children's Holiday Party
Dec. 10: Safety Shoe Vendor onsite
Dec. 24 - Jan. 1: Winter
holidays/Shutdown days - JLab closed
|
|
