Difference between revisions of "Start Counter Material Study"
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| − | We have estimated the effect of the carbon fiber lining for the start counter support structure on the efficiency for detection for protons. Four reactions were studied: | + | We have estimated the effect of the carbon fiber lining for the start counter support structure on the efficiency for detection for protons. Four reactions of the form <math>\gamma p \rightarrow p X</math>were studied: |
| − | + | {| border | |
| − | + | |- | |
| − | + | ! reaction name || generator || photon energy range (GeV) || t-slope (1/GeV) || m<sub>X</sub> (GeV) || Γ (MeV) | |
| − | + | |- | |
| − | + | | b1pi || genr8 || 9.0 || 5.0 || 2.0 || 100 | |
| − | + | |- | |
| − | + | | bggen1 || bggen || ? || 7.0 || 0.5 || 0 | |
| − | + | |- | |
| − | + | | bggen2 || bggen || ? || 7.0 || 1.5 || 0 | |
| + | |- | ||
| + | | bggen3 || bggen || ? || ? || ? || 0 | ||
| + | |} | ||
The material budget is summarized as follows: | The material budget is summarized as follows: | ||
| − | + | [[Image: start counter material.png]] | |
| + | |||
| + | For each reaction, two detector conditions were considered: | ||
# no carbon fiber support | # no carbon fiber support | ||
# nominal (three layer) carbon fiber support | # nominal (three layer) carbon fiber support | ||
| − | Range and energy loss were calculated using the | + | For each reaction, two definitions of "detected" were considered: |
| + | |||
| + | # proton emerges from the start counter, with no requirement on momentum ("appeared") | ||
| + | # proton emerges from the start counter with at least 200 MeV/c of total momentum ("tracked") | ||
| + | |||
| + | Range and energy loss were calculated using the [http://www.calel.org/range.html Range] package. All relevant polar angles were considered. The effect of the magnetic field was not included in this estimate. | ||
Two plots are shown for each reaction: | Two plots are shown for each reaction: | ||
| Line 25: | Line 35: | ||
# "detection" efficiency with the corresponding angular distribution of events in arbitrary units | # "detection" efficiency with the corresponding angular distribution of events in arbitrary units | ||
| − | The colors indicate the definition of "detected" and the absence | + | The colors indicate the definition of "detected" and the absence/presence of the carbon fiber: |
* appeared, no carbon fiber (blue) | * appeared, no carbon fiber (blue) | ||
* appeared, with carbon fiber (red) | * appeared, with carbon fiber (red) | ||
* tracked, no carbon fiber (green) | * tracked, no carbon fiber (green) | ||
* tracked, with carbon fiber (black) | * tracked, with carbon fiber (black) | ||
| + | |||
| + | {| border | ||
| + | |- | ||
| + | ! reaction || p vs. theta || efficiency | ||
| + | |- | ||
| + | | b1pi | ||
| + | | [[Image: B1 pi cut.png|thumb|momentum vs. polar angle, b1pi]] | ||
| + | | [[Image: B1 pi eff.png|thumb|detection efficiency, b1pi]] | ||
| + | |- | ||
| + | | bggen1 | ||
| + | | [[Image: Bggen recoil tst 1 cut.png|thumb|momentum vs. polar angle, bggen1]] | ||
| + | | [[Image: Bggen recoil tst 1 eff.png|thumb|detection efficiency, bggen1]] | ||
| + | |- | ||
| + | | bggen2 | ||
| + | | [[Image: Bggen recoil tst 2 cut.png|thumb|momentum vs. polar angle, bggen2]] | ||
| + | | [[Image: Bggen recoil tst 2 eff.png|thumb|detection efficiency, bggen2]] | ||
| + | |- | ||
| + | | bggen3 | ||
| + | | [[Image: Bggen recoil tst 3 cut.png|thumb|momentum vs. polar angle, bggen3]] | ||
| + | | [[Image: Bggen recoil tst 3 eff.png|thumb|detection efficiency, bggen3]] | ||
| + | |} | ||
Integrated over all angles, the various definitions of detection and detector configurations give: | Integrated over all angles, the various definitions of detection and detector configurations give: | ||
Latest revision as of 01:21, 21 January 2014
We have estimated the effect of the carbon fiber lining for the start counter support structure on the efficiency for detection for protons. Four reactions of the form 
were studied:
| reaction name | generator | photon energy range (GeV) | t-slope (1/GeV) | mX (GeV) | Γ (MeV) |
|---|---|---|---|---|---|
| b1pi | genr8 | 9.0 | 5.0 | 2.0 | 100 |
| bggen1 | bggen | ? | 7.0 | 0.5 | 0 |
| bggen2 | bggen | ? | 7.0 | 1.5 | 0 |
| bggen3 | bggen | ? | ? | ? | 0 |
The material budget is summarized as follows:
For each reaction, two detector conditions were considered:
- no carbon fiber support
- nominal (three layer) carbon fiber support
For each reaction, two definitions of "detected" were considered:
- proton emerges from the start counter, with no requirement on momentum ("appeared")
- proton emerges from the start counter with at least 200 MeV/c of total momentum ("tracked")
Range and energy loss were calculated using the Range package. All relevant polar angles were considered. The effect of the magnetic field was not included in this estimate.
Two plots are shown for each reaction:
- momentum vs. polar angle, with the angle dependent cut for each of the following conditions
- "detection" efficiency with the corresponding angular distribution of events in arbitrary units
The colors indicate the definition of "detected" and the absence/presence of the carbon fiber:
- appeared, no carbon fiber (blue)
- appeared, with carbon fiber (red)
- tracked, no carbon fiber (green)
- tracked, with carbon fiber (black)
| reaction | p vs. theta | efficiency |
|---|---|---|
| b1pi | ||
| bggen1 | ||
| bggen2 | ||
| bggen3 |
Integrated over all angles, the various definitions of detection and detector configurations give:
| reaction | appeared, no carbon fiber (blue) | appeared, with carbon fiber (red) | tracked, no carbon fiber (green) | tracked, with carbon fiber (black) |
|---|---|---|---|---|
| b1pi | 0.9386 | 0.9252 | 0.92285 | 0.90845 |
| bggen1 | 0.7429 | 0.725 | 0.6724 | 0.6589 |
| bggen2 | 0.7925 | 0.7749 | 0.73 | 0.7138 |
| bggen3 | 1 | 1 | 1 | 1 |
