Solid calorimeter beam test

beam test plan

goal

• • learn the feature and performance of the modules.
  • test energy, position and time resolution
  • use test results to anchor our simulation.
  • help design the future SoLID prototype.

time

• test time is Dec 2011 - May 2012, this includes planning, bench test and beam test.
• Beam will be shut down in May 2012
• The shashlyk modules need to be returned to Will Brooks in Chile in Summer 2012.

manpwoer

• Zhiwen Zhao (Xiaochao Zheng's group from UVa)
•  ??? (W&M group)

test preparation

We will use the TPE (two photon exchange) calorimeter for test. It consists of 30 4x4cm COMPASS modules in a 5x6 array and sit in a metal box/frame. The calorimeter was used in TPE experiment in HallB and currently sits at ODU with Larry Weinstein's group. About materials we need for the test. The COMPASS shashlyk modules can be borrowed. The readout (PMT/base/housing) need to be borrowed from DVCS Proton Array with an adapter or new housing to be able to connected to the modules. For electronics, we will find supply in HallA and HallC. For supporting structure, we need to make or borrow them.

We are in communication with Indiana University about borrowing their supporting structure and electronics. That depends on how soon they can finish their test and if others will use some of that. To have our modules put into the their supporting structure, we need to make a mounting.

bench test

• The bench test will be held at Jlab. We will use cosmic rays to do gain matching and to study basic properties such as timing response. A stand-alone DAQ will be used and two scintillator bars placed one above and one below the modules will be used for triggering.

beam test

• the g2p/gep in HallA has target coil and septa blocking forward angle up to 30 degree, this makes it impossible to have elastic electrons with good rate for test.

• the plan is to have it in HallB under the CLAS photon tagger. After passing through a photon radiator and swept by the tagger magnet, electrons with 5-95% of beam energy will pass the photon tagger and hit the floor. We will place the calorimeter module on the floor aligned with electrons at various locations for test.

refer to the plot at [1]

Other test going on under the CLAS photon tagger

• HallD Forward Calorimeter (FCAL) test. Currently, Matthew Shepherd's group at Indiana University is doing a HallD lead glass FCAL test there. They have 25 4x4cm modules in a 5x5 array mounted on a rail. Two sets of 5 scintillator bars on top of each others are used as trigger in a box above the calorimeter modules. Another small scintillator is mounted directly under the tagger counter to work as a veto at the offline stage. Their readout is FADC-based. see their setup at [2] and [3]. More info is at HallD FCAL test wiki [4]. Their writeup, OSP and talk are also collected here [5] in case you have no access to GlueX DocDB.

• HallB Forward Tagger Calorimeter test. The prototype consists of a 3x3 matrix of PbWo crystals 15 mm x 15 mm x 200 mm in size with an APD-based readout. The measurement goal is to determine the timing resolution vs. incident electron energy in the range from roughly 500 MeV to 2 GeV. The test will continue through the first part of next year (May end in Feb or Mar)