At CERN 1 Plus side slice test downstairs
- Slides: 7
At CERN 1. Plus side slice test (downstairs) • Working gas mixture (Ar-CO 2 -CF 4) in system… ready for HV • Thursday will look at cosmics downstairs with layer trigger • Cooling still an issue for USC (computers, FED and TF crates) • LV still an issue… 2. CSC simulation • Attempt to compare simulation with data available with regards to timing… 13 Nov. 2007 G. Rakness (UCLA) 1
Couple of details while looking at drift times from simulation… Recall, “knobs” in CSC simulation are… 1. bunch. Timing. Offsets[chamber type] • Shifts all chambers of a given type by a constant amount (nsec) • ME 1/1 have narrower wire spacing (2. 5 mm 3. 1 mm for other chambers), so drift is different for ME 1/1/ chambers… 2. time. Bit. For. Bx. Zero • Global offset for all wire. Hits from all chambers (bx)… irrelevant… 3. tof. Offset • One correction per wiregroup (per chamber) (nsec) • Compensates for TOF for muons originating at z=0 • Remove this correction so drift times from all chambers can be combined (except ME 1/1, of course…) 4. Smearing parameter to smear arrival time from each wire (at ALCT…) • Default value = 0… 13 Nov. 2007 G. Rakness (UCLA) 2
Analysis of Cosmic Ray Data… Remember August 1998? http: //www-hep. phys. cmu. edu/cms/TALKS/DOE_98_v 3_www. ps N. Terentiev (CMU) Good fit by “semi-gaussian” = Gaussian with 2 independent widths… allowed to be different on one side of the centroid from the other • P 2 = 7. 8 nsec 13 Nov. 2007 • P 3 = 12. 7 nsec G. Rakness (UCLA) 3
Simulation with smearing… Recall, data had… • P 2 = 7. 8 nsec • P 3 = 12. 7 nsec • No tails WITH inclusion of smearing parameter of 2. 2 nsec, simulation has: • P 2 = 6. 1 nsec • P 3 = 11. 8 nsec • Long tail to high end • ME 1/1 peak = 28. 7 nsec • other CSCs’ peak = 37. 3 nsec 13 Nov. 2007 G. Rakness (UCLA) 4
Arrival times for data… N. Terentiev (CMU) With N_layers >=4, the arrival of the data from the n-th layer is… • smoothly increasing from mean of 45 57 nsec • sigma ~ 5 nsec for all hits http: //www-hep. phys. cmu. edu/cms/TALKS/emu 1_00_sep_teren. html 13 Nov. 2007 G. Rakness (UCLA) 5
Arrival times for simulation… WITH smearing of 2. 2 nsec, the simulation has… • smoothly increasing mean from 32 44 nsec • sigma ~ 4. 6 -5. 2 nsec Without smearing, the simulation has • sigma ~4. 1 -5. 1 nsec… 13 Nov. 2007 G. Rakness (UCLA) 6
To do… • Push Heavy Stable Charged Particles through simulation and see how well emulator does at creating: • • 13 Nov. 2007 CLCT ALCT LCTs matched at TF… Check to see if, in this idealized case, HSCP’s will make it through the CSC trigger… G. Rakness (UCLA) 7
