DRAFT version Oct. 15, 2004 Hauser/Mey UCLA 1 Analysis of Oct. 04 Test Beam RPC Data Jay Hauser,...
-
date post
21-Dec-2015 -
Category
Documents
-
view
213 -
download
0
Transcript of DRAFT version Oct. 15, 2004 Hauser/Mey UCLA 1 Analysis of Oct. 04 Test Beam RPC Data Jay Hauser,...
1DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
Analysis of Oct. 04 Test Beam RPC Data
Jay Hauser, Martin von der MeyJay Hauser, Martin von der Mey
University of California Los AngelesUniversity of California Los Angeles
2DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
RPCs in Test Beam• 1 RE1/2 (call it RE1)• 2 free-standing (call
them RE2, RE3)• Readout info for
experts only:• RPC0 RE1• RPC3 RE2• RPC2 RE3
ME1/1
RE1 on ME1/2
ME2/2ME3/2
RE2, RE3 behind
3DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
Link Board to RAT Board Setup
• RAT receives 4 cables, one from each RPC chamber
• Cables 0, 1, 2 were connected
• Appears that phasing RAT-TMB incorrect, so that 0 2 and 13 in readout
• N.B. RE1 seems the healthiest chamber
4DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
RPC-RAT Interface• RAT receives 4 cables with 20 pairs each (3
cables active at test beam)• For each cable/RPC chamber implemented:
• 4 bits of bunch crossing
• 12 bits of RPC pad data
• 1 clock
• (FYI CMS specification is 16 pads, 2 bx, 1 clock, 1 GND)
• New full-size backplane was used
5DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
Data Conditions• Run conditions:
• Link boards arrived Saturday p.m., run ended Sunday evening
• Runs 535-548 have RPC data.
• Data triggered by Sector Processor, not scintillators
• Beam spot roughly 30 cm each dimension
• RAT latches bits on falling edge of 40 MHz clock where they are stable
• Analysis conditions:• Comparison CSC chamber always ME3/2 - part of SP trigger
(ALCT&CLCT required)
• Run 548 taken Sunday.
• Corrupted RPC events not included– Seen at 1% level
– Symptom: as if no RPC cables connected to RAT (?)
6DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
TMB Bunch Crossings - Data• Flat Distribution seen 0-15 (4 bits):
• N.B. no ALCT or TMB data transmission errors (CRC check) seen in these runs
7DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
RPC Bunch Crossings - Expectations
•Emu electronics used orbit=924 bx, RPC used orbit=3564 bx
•These are incommensurate.
•What are lowest 4 bits if synch is perfect?Orbit Emu BX RPC BX Emu starts
(mod16)RPC starts
(mod16)Difference (mod16)
1 0-923 0-923 0 0 0
2 0-923 924-1847 0 12 12
3 0-923 1848-2771 0 8 8
4 0-791, 792-923
2772-3563, 0-131
0, 8 4, 0 4, 8
•Therefore, expect various differences in jumps of 4 bx
•In general, there can also be an offset due to time delay of BX0
8DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
RPC Bunch Crossings - Data• TMB vs RPC see perfect agreement with
expectations.• At least, ALCT/CLCT bx reset/bx0 protocol =
Link board protocol
9DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
RPC BX from different RPC Chambers?
• Nice diagonals, but offsets (2, 7 bx) due either to TTCrx offset or reset timing at Link board
10DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
Beam Spot Size• Data triggered by SP covers roughly 30x30 cm• (Scintillators are 10x10 cm)
Key ½-Strip
Key
½-S
trip
Key Wire Group
11DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
RE1 Pad Data Quality• Compare ME3/2 (rear chamber) CLCT key half-strips (not strips)
to RE1 pad (vertical dimension)• Good position agreement (one dead pad)• Modest RPC efficiency within readout region• Fiducial region for RE1 select half-strips 65-100
RPC Pad
Key
½-S
trip
12DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
RE1 Efficiency Within Fiducial Region• Unsure exactly where pads are, so plot
efficiency versus CSC wire group• This RPC chamber fairly efficient
Key Wire Group
13DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
RE2 Pad Data Quality• Same comparison• Active part of chamber appears far from beam centerlow statistics• Fiducial region: select half-strips 10-50
Key
½-S
trip
RPC Pad
14DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
RE2 Efficiency Within Fiducial Region• This RPC chamber not so efficient
Key Wire Group
15DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
RE3 Pad Data Quality• Same comparisons• Fiducial region: select half-strips 80-115
Key
½-S
trip
RPC Pad
16DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
RE3 Efficiency Within Fiducial Region• RE3 efficiency reaches a high value, but is not
flat with wire number
Key Wire Group
17DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
RPC versus ALCT Timing• First RPC hit per chamber:• RE1, RE2 all in one BX• RE3 not as good• Note RE1 later by 1 BX
RE1RE2
RE3
18DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
RPC Afterpulsing?• Number of time bins per chamber per event• RE1 and RE2 good, RE3 shows considerable
after-pulsing:
RE1RE2
RE3
19DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
RPC Pads Hit• Pads hit per event (summed over time bins)• All look okay (RE1 slightly more pads)
RE1
RE2RE3
20DRAFT version Oct. 15, 2004 Hauser/Mey UCLA
Summary• RPC Link Board to RAT-TMB data
transmission worked well• RPC pads well correlated to CSC position• Timing looks strange on one RPC chamber• RPC efficiency hard to study
• Instrumented region was small
• Gas was not optimal due to safety concerns
• Will be useful to do simultaneous analysis of RPC data taken through Link board readout – is it possible to double-check?
• N.B. time for doing tests was way too short. Is there some way to set up a cosmic ray test bench for a longer time?