Difference between revisions of "10-30-08 GEM HRRL Photon Runs"
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| + | The Goal today is to observe the GEM detector output when hit with MeV photons | ||
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=14 MeV photons= | =14 MeV photons= | ||
We are sending 14 MeV phtoton through a 4" thick brick wall collimator. A 4" Al brick in front of the HRRL exit port is used as a FC. | We are sending 14 MeV phtoton through a 4" thick brick wall collimator. A 4" Al brick in front of the HRRL exit port is used as a FC. | ||
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| + | FC: 223B2 | ||
| + | NaI: 223B5 | ||
| + | Acc Gate: 223B8 | ||
| + | GEMtrig: 223B3 | ||
Vdrift= 3700 Volt | Vdrift= 3700 Volt | ||
VGem=3400 | VGem=3400 | ||
| + | IGem=815 microA | ||
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| + | |||
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| + | The scope trace below shows output when electron beam current is 9 mA. | ||
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| + | [[Image:10-30-08_14MeV9mAHRRL_GEM_strip8.png | 200 px]] | ||
The scope trace below shows output when electron beam current is 18 mA. | The scope trace below shows output when electron beam current is 18 mA. | ||
[[Image:10-30-08_18mAHRRL_GEM_strip8.png | 200 px]] | [[Image:10-30-08_18mAHRRL_GEM_strip8.png | 200 px]] | ||
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| + | The scope trace below shows output when electron beam current is 36 mA. | ||
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| + | [[Image:10-30-08_14MeV36mAHRRL_GEM_strip8.png | 200 px]] | ||
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| + | The scope trace below shows output when electron beam current is 55 mA. | ||
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| + | [[Image:10-30-08_14MeV55mAHRRL_GEM_strip8.png | 200 px]] | ||
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| + | Now Max Gain on GEM | ||
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| + | Vdrift= 3800 Volt | ||
| + | |||
| + | VGem=3500 | ||
| + | IGem=841 microA | ||
| + | |||
| + | The scope trace below shows output when electron beam current is 9 mA. | ||
| + | |||
| + | [[Image:10-30-08_14MeV9mAHRRL_GEM_strip8_Vd3800.png | 200 px]] | ||
| + | |||
| + | The scope trace below shows output when electron beam current is 4 mA. | ||
| + | |||
| + | [[Image:10-30-08_14MeV4mAHRRL_GEM_strip8_Vd3800.png | 200 px]] | ||
| + | |||
| + | =10 MeV photons= | ||
| + | |||
| + | The scope trace below shows output when electron beam current is 20 mA. | ||
| + | |||
| + | [[Image:10-30-08_10MeV20mAHRRL_GEM_strip8_Vd3800.png | 200 px]] | ||
| + | |||
| + | Peak amplitude is same but rate is much lower | ||
Latest revision as of 23:04, 30 October 2008
The Goal today is to observe the GEM detector output when hit with MeV photons
14 MeV photons
We are sending 14 MeV phtoton through a 4" thick brick wall collimator. A 4" Al brick in front of the HRRL exit port is used as a FC.
FC: 223B2
NaI: 223B5
Acc Gate: 223B8
GEMtrig: 223B3
Vdrift= 3700 Volt
VGem=3400 IGem=815 microA
The scope trace below shows output when electron beam current is 9 mA.
The scope trace below shows output when electron beam current is 18 mA.
The scope trace below shows output when electron beam current is 36 mA.
The scope trace below shows output when electron beam current is 55 mA.
Now Max Gain on GEM
Vdrift= 3800 Volt
VGem=3500 IGem=841 microA
The scope trace below shows output when electron beam current is 9 mA.
The scope trace below shows output when electron beam current is 4 mA.
10 MeV photons
The scope trace below shows output when electron beam current is 20 mA.
Peak amplitude is same but rate is much lower