GlueX Target Meeting, May 17, 2011
From GlueXWiki
Contents
Location, Time
Tuesday, April 12, 2011
1:00 pm EST
JLab: CEBAF Center, Room F326/327
Agenda
- Review minutes from previous meeting: all
- Target Mechanical Design: Tim, Chris
- MOU status: Mark
Communication
Video Conferencing
- ESNet: 8542553
- EVO:
- Meeting URL: http://evo.caltech.edu/evoNext/koala.jnlp?meeting=vsvivIe8eIItIvasatItas
- Phone Bridge ID: 322 6191
Telephone
To connect by telephone:
- dial:
- US and Canada: (866)740-1260 (toll free)
- International: (303)248-0285 (toll call) or look up toll-free number at http://www.readytalk.com/intl
- enter access code followed by the # sign: 3421244#
Slides
Talks can be deposited in the directory /group/halld/www/halldweb1/html/talks/2011-2Q
on the JLab CUE. This directory is accessible from the web at https://halldweb1.jlab.org/talks/2011-2Q/ .
Minutes
Present: Hovanes Egiyan, Mark Ito, Chris Keith, Rory Miskimen, Tim Whitlatch (chair), Elliott Wolin
- Tim brought along drawings and notes made two years ago, modeled on the Hall B cryotarget.
- We may need to pick Steve Christo's brain, especially about lessons learned in Hall B.
- The Hall B targets are Kapton, with DP190 epoxy joining the seams. The scattering chambers are made of Rohacell.
- We will have to perform pressure tests on the cells. Current code may be more stringent than standards at the time the Hall B targets were commissioned.
- The refrigerator will be bought in October or November.
- The model being considered can liquify hydrogen starting from room temperature, at about a liter per hour, corresponding to 15 watts at 20 K. Liquid hydrogen volume looks to be of order a liter. Helium-4 will take longer to liquify.
- The requirement that we want to be able to empty/fill the target on the time-scale of a few hours (preferably less) was restated.
- The refrigerator have no cold moving parts.
- We will have to design and build the heat exchanger and heating element. The refrigerator will stay on continuously and temperature of the hydrogen controlled with a heater in the cold head.
- The gas panel can probably copied from that used by Q-Weak.
- Mechanical considerations
- The target, its plumbing, and the refrigerator (including cold head) will all be a "rigid body". Adjustment of the position of the target on the beam line will be accomplished by positioning the entire structure.
Items for the Next Meeting
- Chris will create a P&I diagram for the gas/refrigerator system
- Chris will distribute the manual for the refrigerator so others can get started thinking about the relevant controls and monitoring.
- We will invite Steve to the next meeting.
- Next meeting in about a month.