RPC status D Piccolo LNF INFN 1 Muon

RPC status D. Piccolo – LNF INFN 1 Muon Barrel Workshop - July 5/7 2010

Overview �RPC Hardware status �RPC Barrel detector Efficiency from collisions data �RPC cluster size �RPC timing synch �Conclusions 2 Muon Barrel Workshop - July 5/7 2010

RPC Detector status �Barrel: �Dead channels (including Dead chambers): ~0. 6/0. 8 % �Masked channels: ~0. 6/0. 8 % 3 For Analysis we marked the following rolls as problematic �Dead: 11 rolls �Masked: 8 rolls with at least one full chip Muon Barrel Workshop - July 5/7 2010 masked � Noise rate and Masked strips: �Noise rate is monitored RUN by RUN. �Strips exceeding predefined threshold rates are masked �Part of them can be recovered increasing electronic threshold �Threshold to define a strip noisy has been changed in different periods

Masking procedures �Several studies to mask nosiy strips: �Intial Conservative approach: mask all channels exceeding 10 hz/cm 2 (total number of masked channels 2. 7 %) �Increasing electronic threshold and total unmasking (total number of masked channels 0. 2 %) �Very high noise rate �Mask all channels exceeding 1 khz/cm 2 (total number of masked strips 0. 4 %) �Still few chambers with high noise �At moment masked all channels exceeding 100 hz/cm 2 (total number of masked channel 0. 8 %) 4 Muon Barrel Workshop - July 5/7 2010

RPC Detector Performance: Data selection � RPC efficiency calculation is based since CRAFT period on the extrapolation of DT/CSC segments on the RPC plane. � For each extrapolation on a given RPC Roll (2 or 3 rolls per chamber) Efficiency, Cluster size, BX is computed looking at RPCRec. Hits in a range of +/- 2 strips. � From RUN 135808 our staring point is the Mu. Monitor PD � We run a skim to select tracker and global muons � Lumi sections with conditions (by mean of JSON file) GOOD and ON for the following detectors: CSC, DT, RPC, Tracker � L 1 Technical trigger bits configuration: 40 OR 41 AND NOT (36 OR 37 OR 38 OR 39) � Request on HLT_Min. Bias. BSC (seeded by L 1 Technical Trigger bits configuration (32 OR 33 OR 40 OR 41)) � Filtering on good vertexes (ndof>4, |z|<15, d 0<2) and removing tracker scraping events � At least one tracker muon within |eta| < 1. 6 with TM Last Station Ang Tight ID OR � At least one global muon within |eta| < 1. 6 with at least one valid hit in the outer (muon) track 5 Muon Barrel Workshop - July 5/7 2010

RPC Detector Performance: the method Extrapolate segments used in the muon Reconstruction on the RPC plane For each extrapolation on a given chamber Check if a RPC hit is present at a distance below 2 strips from the impact point 6 Muon Barrel Workshop - July 5/7 2010

Number of extrapolated segments per roll In the Analysis exclude rolls with less than 16 extrapolated RUN 135808 - 138751 segments Statistics is increasing: At moment 57 RB 4 Roll with low statistics 7 Muon Barrel Workshop - July 5/7 2010

A single wheel rolls with less than 16 Extrapolated segments 8 Muon Barrel Workshop - July 5/7 2010

Efficiency Distribution 9 Muon Barrel Workshop - July 5/7 2010

Efficiency Distribution Good rolls 10 Muon Barrel Workshop - July 5/7 2010

Average Cluster size distribution Average cluster size Larger than in CRAFT 08: 9. 2 k. V Collisions 10: HV 9. 3 k. V Effect of segment slope: Segments with large slopes in internal layers (wrok in progress) 11 Muon Barrel Workshop - July 5/7 2010

RPC Timing Initial synch Based on cosmic And cable length Data selection Method A: Events selection: • RPC trigger present in event Important: signal extension on TB (ORing over 3 BX) Chambers selection: • Tracker track points to the RPC chamber and RPC trigger Mainly Endcap OR Method B: Events selection: • global. Muon present in event Chambers selection: • global. Muon points to the RPC chamber Timing correction have been applied in different perio According to the statistc increase: The hits are synchronized i. e. assigned to the clock period (BX). One of the synchronization parameters is a position of the synchronization window, which can be adjusted in 0. 102 ns steps. 12 Muon Barrel Workshop - July 5/7 2010

RPC Timing 13 Muon Barrel Workshop - July 5/7 2010

Conclusions � Commissioning phase for barrel system is almost done � Timing synch in good shape (less than 0. 2 % of hits not in BX 0) � Noise is under control we reached a compromise between number of masked channels and noise rate (1. 6 % masked+dead channels) �Still details to be studied on the effect of particular noisy region on trigger � Efficiency for chamber without hardware problems is 14 around 95 % (good agreement with CRAFT 09 results and laboratory test) � Cluster size- to better investigated Muon Barrel Workshop Julybe 5/7 2010 �Correlation with other parameters to spot overvoltaged