Monte Carlo simulations of the rates in the forward endcap.

Performed with DPM at 15 GeV/c momentum for 10^7 antiprotons per second.

Done by Torsten Schroeder October 2012.

Crystal position no threshold above 0 MeV above 1 MeV above 3 MeV above 10 MeV
  rate/s <E> rate/s <E> rate/s <E> rate/s <E> rate/s <E>
2nd xtal next to hole (VPTT) 10^7 4.2 MeV 1.1 10^6 35.8 MeV 533 10^3 77 MeV 330 10^3 123 MeV 210 10^3 188 MeV
highest rate APD 10^7 0.5 MeV 410 10^3 12.9 MeV 160 10^3 33 MeV 88 10^3 58 MeV 48 10^3 102 MeV

-- FritzHerbertHeinsius - 29 Aug 2014

Monte Carlo simulations of the radiation dose of APDs for the forward endcap.

Done by Bernhard Roth (RUB) Oktober 2012. Assumptions: APD of 200 um Si behind the crystals. Beam momentum of 15 GeV/c. Luminosity of 2*10^32 cm^-2s^-1. 10 half years data taking. Please note, that this is the peak luminosity. The average luminosity is a factor of 2 lower. So all values of the table below have to be divided by 2.

Theta [deg] Rate [mGy/h] Dose [Gy] APD hits [1E10]
5.78 10.48 459.02 131.86
7.13 7.17 314.04 83.54
8.46 4.69 205.44 56.61
9.80 3.34 146.49 40.77
11.11 2.16 94.72 29.42
12.44 1.85 81.14 22.55
13.72 1.31 57.50 16.91
15.03 1.02 44.88 13.82
16.29 0.81 35.65 10.53
17.58 0.73 31.81 8.91
18.80 0.50 22.09 6.75
20.07 0.39 17.03 5.18
21.26 0.29 12.60 3.55
22.50 0.18 8.05 2.23

APDs are used up to theta of 14.4 degree. In the inner regions VPTT are foreseen.

Taking into account the average luminosity of 1*10^32 cm^-2s^-1 and the range of APDs from 22.5 to 14.4 degrees results in a lifetime dose of 4 Gy to 26 Gy.

For more details please check this document: bernhardDoseStudy.pdf (Radiation study by Bernhard Roth (RUB))

Monte Carlo simulations of the dose in the forward endcap (page 17), indico login required:

https://indico.gsi.de/getFile.py/access?contribId=5&sessionId=0&resId=0&materialId=slides&confId=4582

-- FritzHerbertHeinsius - 08 Jan 2021
Topic revision: r5 - 2021-01-08, FritzHerbertHeinsius
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