Difference between revisions of "Study of SHMS resolution"
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!no wire chamber smearing, no multiple scattering in material || 0.08 || 0.01 || .014 || .002 | !no wire chamber smearing, no multiple scattering in material || 0.08 || 0.01 || .014 || .002 | ||
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! wire chamber smearing, no multiple scattering in material || 0.36 || 0.26 || .038 || .084 | ! wire chamber smearing, no multiple scattering in material || 0.36 || 0.26 || .038 || .084 | ||
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! wire chamber smearing, multiple scattering in material with vacuum pipe || 1.00 || 0.94 || .072 || .12 | ! wire chamber smearing, multiple scattering in material with vacuum pipe || 1.00 || 0.94 || .072 || .12 | ||
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! wire chamber smearing, multiple scattering in material with helium bag || 1.04 || 0.96 || .092 || .14 | ! wire chamber smearing, multiple scattering in material with helium bag || 1.04 || 0.96 || .092 || .14 | ||
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Revision as of 11:47, 28 February 2012
Using the following setup for SHMS single arm MC
- 2 GeV , 20 deg scattered electrons
- Reconstruction of tracks in the focal plane assumed 200 microns resolution.
- LH2 target with 20cm length. Assume beer can with radius of 3.37cm and wall thickness in 0.005in Al.
- 16 mil Al scattering chamber window (X0=8.89cm) followed by 15 cm air (X0=30420cm)
- Spectrometer entrance window 15 mil Kevlar (X0=74.6cm) and 5 mil Mylar (X0=28.7cm)
- Spectrometer exit window spectrometer exit window, 15 mil Kevlar, 5 mil Mylar (use 20 mil,X0=53.3)
- Two options in Hut when AR/Neon Cerenkov is removed
- Vacuum pipe so the the spectrometer exit window is moved to location of Cerenkov exit window
- Helium bag. The spectrometer exit window is located in front of Cerenkov entrance, but the Cerenkov is replaced by a helium bag. Assume the entrance and exit of helium bag is aluminized mylar. Each window is 17 micron mylar and 3 micron aluminum. Filled with helium ( Radlen = 754560 cm).
- Drift through air until drift chamber 1
- Chamber 1 entrance foil, 1 mil of Mylar
- Scattering in drift chamber, for each plane
- Effective cathode plane, Be/Cu with Rad Len = 28.7cm , 0.0005 in
- Drift through Chamber gas, 50/50 ethane/argon with Rad Len = 16700.0cm
- Effective wire plane, 25 micron W+Be/Cu
- Fill hit position for plane
- Drift through Chamber gas, 50/50 ethane/argon with Rad Len = 16700.0cm
- Chamber 1 exit foil, 1 mil of Mylar
- Drift through air until drift chamber 2
- Chamber 2 entrance foil, 1 mil of Mylar
- Scattering in drift chamber, for each plane
- Effective cathode plane, Be/Cu with Rad Len = 28.7cm , 0.0005 in
- Drift through Chamber gas, 50/50 ethane/argon with Rad Len = 16700.0cm
- Effective wire plane, 25 micron W+Be/Cu
- Fill hit position for plane
- Drift through Chamber gas, 50/50 ethane/argon with Rad Len = 16700.0cm
- Chamber 2 exit foil, 1 mil of Mylar
Comparing resolutions with vaccuum pipe versus helium bag
- Table with the sigma for all events
| mc FLAGS | Xptar (mr) | Yptar (mr) | Delta % | Ytar (cm) |
|---|---|---|---|---|
| no wire chamber smearing, no multiple scattering in material | 0.08 | 0.01 | .014 | .002 |
| wire chamber smearing, no multiple scattering in material | 0.36 | 0.26 | .038 | .084 |
| wire chamber smearing, multiple scattering in material with vacuum pipe | 1.00 | 0.94 | .072 | .12 |
| wire chamber smearing, multiple scattering in material with helium bag | 1.04 | 0.96 | .092 | .14 |
