March 16 Newsletter
From APEXwiki
Dear APEX Collaboration members,
In the last week (March 8-12), we have gotten much closer to final plans for the June test run! The Run Plan for the June test run is presently being reviewed.
After approval, we will send announcements regarding the shift schedule. The shifts will need to start May 20 for installation and commissioning, followed by data taking and online analysis in June. To prepare, it may be useful for APEX members not experienced with taking shifts at Hall A to take some on PREX. Please see PREX website
Below is a summary of recent activity and current priorities for the sub-groups.
(See also previous newsletter)
Contents |
Status Report and Priority Activities for the Week of March 7-13
Detector Preparation and Installation
Group: Bogdan Wojtsekhowsi (leader), Jack Segal, Doug Higinbotham, Albert Shahinyan
On the detector hardware there are several items to report:
- HRS-L: 52 A/D cards are ready for installation.
- All required level translators are installed and powered.
- All cables and supports are ready.
- Installation of the A/D cards in the VDC will be done after the PREX run.
- S0 on HRS-L: time resolution with 1877 TDC was tested.
The result is 0.5~ns (sigma) which is sufficient for experiment.
The plan for next week is to produce cables for the HRS-R and test HRS-R S0 performance.
Target
Group: Kenneth Moffeit (leader), Dieter Walz, Clive Field, Marco Oriunno, John Jaros, Takashi Maruyama, Allen Odian, Dave Meekins, Bogdan Wojtsekhowski, Alan Gavalya, Ed Folts
The target team has decided to continue development of three target components:
- Alignment: target with several well-separated horizontal and vertical Tungsten wires
- Optics calibration: Carbon foils
- Production target: Narrow strips of Tantalum foil, oriented perpendicular to the beam direction.
Marco Oriunno is creating engineering drawings for these three targets, to begin procurement by early April. The JLab team is coordinating both the target cooling (using room-temperature dry Nitrogen gas) and installation.
Below, for illustration, are pictures of the target enclosure with the PREX target, and a closer view of the optics calibration section of the PREX target.
Optics
Group: Vincent Sulkosky (leader), Jin Huang, Doug Higinbotham, John LeRose, Tim Holmstrom
The optics group has been formulating requirements for the optics and alignment sections of the target. In the next week they will start creating a run plan for optics calibration.
Septa
Group: John LeRose (leader), Paul Brindza, Ed Folts, Jack Segal
John LeRose has done an analysis of the expected optics quality in the right HRS, when its polarity is reversed after optics calibration. The analysis shows that the error from switching polarity will be small.
The group recently identified a small dipole component in the PREX septa when the polarity of one side is reversed. A small compensating magnet must be placed upstream to compensate for the resulting deflection. An available magnet has been identified, and an evaluation of its how this deflection will affect the experiment is ongoing.
VDC Analysis
Group: Ole Hansen (leader), Jin Huang, Michael Paolone, Guy Ron
The group has identified a previous dataset collected with high rate in the gas cherenkov counters. The group will use this data to test the new VDC analysis software before the June test run.
Analysis Tools
Group: Ishay Pomerantz (leader), Eli Piasetzky, Ran Shneor, Mathew Graham, Eric Jensen, Victor Maxwell, Sergey Abrahamyan
The analysis group had a meeting last week, and the website has been updated with a list of calibration tools that need to be developed before the June Test Run. The following collaboration members have taken up the responsibility to develop different tools (in collaboration with various experts):
- Ishay Pomerantz and Ran Shneor: lead glass detectors
- Mathew Graham: Gas Cherenkov Counters
- Sergey Abrahamyan and Victor Maxwell: s2m scintillator plane
- Eric Jensen (in collaboration with Todd Averett): s0 scintillator plane
We suggest that all analysis group members use the APEX website to communicate their progress on a weekly basis.
Ramesh Subedi has pointed us to runs that have high rate readings for the Gas Cherenkov Counters, which will be useful in developing these tools.
Very soon we will need to make a list of the plots that are needed to diagnose the calibration of the various detectors components during the June Test Run.
Additional Remarks
We encourage everyone to provide us with feedback and suggestions as we prepare for the Test Run this June.
Thank you and kind regards,
Rouven, Philip, Natalia, and Bogdan (APEX spokespeople)
