Difference between revisions of "Total Absorption Counter"
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(→CLAS Total absorption counter used for PrimEx) |
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| Radiation Length of material (Web) || align=center | ~25mm | | Radiation Length of material (Web) || align=center | ~25mm | ||
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+ | | Critical Energy (Web) || align=center | 15.8 MeV | ||
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| Refractive index (Web) || align=center | 1.67270 | | Refractive index (Web) || align=center | 1.67270 |
Revision as of 15:42, 9 March 2017
CLAS Total absorption counter used for PrimEx
The table below summarizes the information I obtained from various sources about the TAC counter that GlueX borrowed from CLAS.
Property (source) | Value |
---|---|
Material (from Mahbub) | SF-5 Lead Glass |
Composition by weigth (Web) | 55% PbO, 38% SiO2, 5% K2O, 1% Na2O |
Length (from Mahbub) | 40cm |
Height (from Mahbub) | 20cm |
Width (from Mahbub) | 20cm |
Weight of lead-glass block | 65 kg |
Density (Web) | 4.08 g/cm^3 |
Radiation Length of material (Web) | ~25mm |
Critical Energy (Web) | 15.8 MeV |
Refractive index (Web) | 1.67270 |
PMT (from Mahbub) | 5 inch Hamamatsu R1250 PMT |
options considered earlier
- lead-glass counter array:
- efficiency ~100%
- to avoid radiation damage: rate < 100kHz using radiator of 10-5 X0 and ~100 pA beam
- Cerenkov counter (higher current - but probably lower efficiency)