Photon Beam Polarimetry
From GlueXWiki
This page contains a list of to do items for installing the triplet polarimeter for the Spring 2015 GlueX run. Items that used to be on this page are now at the bottom in Items From Before January 2015
Contents
Expected Timeline
- February 2 - 5 (?): Kei visits ASU
- mid-February: ship triplet to JLab
- First week after delivery: Survey by JLab
- February 16 - March 27: installation
- March 28 - April 2: testing
- April 3 - May 4: physics beam
Hardware Division
- ASU
- motor (data sheet)
- controller
- power supply
- 4 channels of +12V, 0.21 amps per channel
- 4 channels of -12V, 0.21 amps per channel
- 1 channel of +200V, the leakage current on the silicon strip detecter is 3.3 micro-amps
- 32 short SSI cables with Lemo
- vacuum rated limit switches (data sheet)
- JLab
- fADCs
- 2 fADC250s on PSC VXS crate
- 32 coax cables with Lemos on both ends (Fernando). Require 55ft to racks
- turbo vacuum pump (Tim)
- fADCs
Things to do at ASU
- packaging, shipping
- testing(?)
Things to do at JLab
- preparation of hardware before shipment
- installation
- Monitoring
- Would like to run the device below 50 mTorr to avoid voltage breakdown. Need pressure sensor, monitoring (Note: this is being extremely cautious. We will be running at ~200V, and even with 300V the required pressure is, given d = 1mm, <6Torr)
- Humidity: no requirements
- Temperature: would like to monitor temperature in collimator cave since we don't want the preamps to get too hot. Need temperature sensor, monitoring
- testing with source(?)
Management/Safety
- write proposal, safety concerns/procedures
- Current Triplet Installation Procedure Document pdf docx
- Current Safety Hazard Analysis Sheet pdf doc
- Link to Task Hazard Analysis worksheet
- Link to Beryllium handling procedure at JLab EH&S
- example document for FCAL dark room (DOC)
- Hall D Beam Line Vacuum Procedures document (PDF) - reuse (?) → Tim
- example document for FCAL Hazard Analysis (DOC)
- Beryllium use:
- will be used as radiator foil, 25μm thick
- Get approval from Bert
- Pass by Patritzia
Analysis Procedures
- beam requirements
- requirements on other systems (PS, tagger)
- analysis procedure
- Think of procedure for high-level analysis to ensure data is good
- online monitoring
- fADC scalers for monitoring each sector → Hovanes
- RootSpy plugin
- MC - GEANT4 simulation available with previous geometry
Items From Before January 2015
- Studies of some direct photon polarimetry possibility for the meeting on November 1, 2010
- Azimuthal asymmetries from Geant4 polarized pair production on January 10, 2011
- triplet polarimeter presentation at May 2012 collaboration meeting
- July 6 2012 teleconference regarding triplet polarimeter
- Monte Carlo code