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D Acosta,
G Apollinari,
K Arisaka,
V. Barasko,
N. Bondar,
R. Breedon,
A. Bujak,
B Bylsma, N. Chester,
D Chrisman, [......],
V. Souvorov,
V. Sytnik,
B Tannenbaum,
N Terentyev,
S.M. Tripathi,
S. Villa,
A Volkov,
A Vorobyov,
V. Yarba,
G Zilizi
[show abstract]
[hide abstract]
ABSTRACT: Presented are the main design features and performance results of the cathode strip chambers (CSCs) for the CMS Endcap Muon System. The six-plane structure of these chambers yields a spatial resolution of about 80 μm, essentially uniform and independent of the strip width (up to 16 mm, which is unusually wide for the cathode-to-anode wire distance of 5 mm). In addition, the net spatial resolution of about one-tenth of the strip width at the hardware trigger level (300ns) is obtained using a simple network of comparators. The time resolution achieved at the trigger level is ∼4ns (RMS) that allows unambiguous tagging of bunch crossing occurring every 25 ns. Aging tests, including those obtained with a recirculating gas system, showed only minor aging effects. The aging studies were performed with large-scale chambers; 700 m of wire were irradiated for a dose up to 0.4 C/cm of the total accumulated charge.
Nuclear Science Symposium Conference Record, 2002 IEEE; 12/2002
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D Acosta,
G Apollinari,
K Arisaka,
N Bondar,
R Breedon,
A Bujak,
B Bylsma, N Chester,
R Clare,
D Cline, [......],
N Terentyev,
M Tripathi,
S Vavilov,
S Volkov,
A Vorobyov,
I Vorobyov,
L Wang,
V Yarba,
L Zhou,
Z Zhu
[show abstract]
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ABSTRACT: Two CMS production Cathode Strip Chambers were tested for aging effects in a high-radiation environment at the Gamma Irradiation Facility at CERN. The chambers were irradiated over a large area: in total, about 2.1 m 2 or 700 m of wire in each chamber. The 40%Ar+50%CO 2 +10%CF 4 gas mixture was provided by an open-loop gas system for one of the chambers and by a closed-loop recirculating gas system for the other. After an accumulation of 0.3-0.4 C per centimeter of a wire, equivalent to about 30 to 50 years of operation at peak LHC luminosity, no significant changes in gas gain, chamber efficiency, and wire signal noise were observed for either of the two chambers. The only consistent signs of aging were a small increase in dark current from ~2 nA to ~10 nA per plane of 600 wires and a decrease of strip-to-strip resistance from 1000 GΩ to 10-100 GΩ. Disassembly of the chambers revealed deposits on the cathode planes, while the anode wires remained fairly clean.
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D Acosta,
G Apollinari,
K Arisaka,
J Blomquist,
R Breedon,
N Bondar,
Yu Bonushkin,
E Borissov,
A Bujak,
B Bylsma, [......],
V Sytnik,
B Tannenbaum,
N Terentyev,
M Tripathi,
S Vavilov,
S Villa,
A Volkov,
A Vorobyov,
V Yarba,
G Zilizi
[show abstract]
[hide abstract]
ABSTRACT: Presented are the main design features and performance results of the Cathode Strip Chambers for the CMS Endcap Muon system. Although the strips are unusually wide (up to ) for the cathode-to-anode wire distance of , the six-plane structure of these chambers yields a spatial resolution of about , essentially uniform and independent of the strip width. In addition, the net spatial resolution of about one-tenth of the strip width at the hardware trigger level is obtained using a simple network of comparators. Time resolution achieved at the trigger level is (rms) that allows unambiguous tagging of bunch crossings which occur every . Aging test results, including those obtained with a recirculating gas system, are discussed; only minor aging affects were observed. The aging studies were performed with large-scale chambers; of wire were irradiated for a dose up to of the total accumulated charge.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
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D Acosta,
G Apollinari,
J Blomquist,
R Breedon,
N Bondar,
Yu Bonushkin,
E Borissov,
A Bujak,
B Bylsma, N Chester, [......],
C Rush,
J.-C Santiard,
S Sedov,
B Smith,
S Sobolev,
V Soulimov,
B Tannenbaum,
N Terentyev,
A Vorobyov,
V Yarba
[show abstract]
[hide abstract]
ABSTRACT: Presented are the main design features of the large Cathode Strip Chambers (CSCs) for the CMS Endcap Muon System as well as the performance results obtained with the two full-scale 3.4×1.5 m2 six-plane prototypes. The prototype performance was within the baseline requirements: (a) higher than 99% efficiency of muon track finding at the trigger level with more than 92% probability for bunch crossing identification and better than 2 mm spatial resolution, and (b) better than 150 μm spatial resolution in off-line.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
