Difference between revisions of "Sampling Calorimeter"

Revision as of 13:33, 12 February 2013

Links

• pages from HERA-B Technical Design Report
• HERA-B Calorimeter NIM article by G. Avoni et al .Nucl.Instrum.Meth. A580 (2007) 1209-1226. DESY server version
• Conference contribution describing the calorimeter electronics.
• NIM article on the PHENIX EmCal. Phenix Thesis which has sections on the EMCal.
• NIM article on IHEP prototype EmCal for PANDA.
• Test facilities
  • ESTB at SLAC (2.5-15GeV electron)
    • news
    • user meeting 2012
    • workshop 2011
  • Fermilab (32 - 1 GeV: Pions, electrons, kaons, or broadband muons)
  • Idaho (<48MeV electron)
• Directory of calorimeter papers collected by Zhiwen Zhao.
• SBS Meeting 06/02/2013 presentation of Carlos Ayerbe

Test setup

Nomenclature of the modules (could be changed)

In order to identify the different modules, the following structure is used:

X-YY-Z

with:

• X = O (outer) or M (middle)
• YY= 01, 02, 03, 04 ...
• Z (only Middle modules) = A, B, C, D

HV control

HV modules were tested by running -2000V across a 5 Megaohm resistor. we measured the voltage out and current out. The histogram below is the percent error in expected current values. The PDF is the charts holding the data taken during the test. Once the HV mosules are back in the TEDF another (more accurate) test may or may not be performed.

File:HV TEST2.pdf

Histogram

Light Leaks sealing

The modules were sealed from light leaks with the use of black tape. To check the sealing, the output of the PMT was measured with an micro-amperimeter, before and after the cover with tape. In top of the pipe, where the PMT is allocated, a gum stopper with slits for the cables, are placed. After many checks it was found that:

• the main light leak come for the joint of the module with the PMT allocation pipe. (Covering it, reduce the current drain from PMT aproximatly in 1-2 orders of magnitude)
• covering the cap of the pipe, doesn't show significant improve.
• covering with tape the side corners of the module, the joint of the top and bottom plastic caps and the union of the pipe with the module reduce the current drain from PMT in 4-5 orders of magnitude.

Outer Modules

For the outer modules, the same PMT was used, with a voltage of 1000 V (max 1900 V) to avoid damage to the PMT.

Middle Modules

For the middle modules, the same PMT was used, with a voltage of 1000 V (max 1900 V) to avoid damage to the PMT.

Trigger

This is the flow chart for the current trigger logic. We are using 3 scintillators; 1 double sided (2PMTs) on top, and 2 separate scintillators on bottom. The difference between threshold voltages is to match gains, this was not done by adjusting HV since presently using HV units with dual outputs for one HV setting.

Trigger Logic Chart

Scheme of cables

Scheme of the HERA-B modules. The orientation is as follows: top view with the rack modules at its left. Each module is indicated by its nomenclature (explained above), the DAQ and HV cable number (in red) and the signal cable (sgn).

Red: the number of the channel (for DAQ and HV label). Sgn: cable signal label.

Cosmic Test

• Initial cosmic test could not have the entire calorimeter with HV since Jack has borrowed the Lecroy HV Crate.
• Replay data
  • login as gep5, cd Desktop/eel122
  • to create root tree:
    • analyzer
    • at analyzer prompt type: decodeEel(Run number)
    • Create root tree in file eeltestrun#.root
    • then quit analyzer with: .q
• Analyzer root tree
  • type: root eeltestrun#.root
• Calo HV on O-01,O-02,O-03,O-04 in ADC channels 0,1,2,3
• Scint HV on Top left, Top right, Bot 1, Bot 2 in ADC channels 24,21,23,22 for run 33 . After run 33 adc channels 8,5,7,6
• Trigger shown above.
• Run sheet: