Test beam 2001 Results M.C. Fouz Muon Week, CERN Nov 01

 Few comments about T0´s  Results with CAEN TDCs and with the final ROB  Drift velocity  Resolution  Efficiency  A first look at the 25ns LHC beam-like data All results are preliminary

SL  1 C27 SL  2 C26 SL  C20 336ns 335ns 333.3ns 335.8ns335ns 336.9ns 338.8ns343.8ns 342.5ns In SL  : Differences of ~6ns between L1,L3 and L2,L4 ?

SL  1 C27 SL  C20 The 6ns T0r difference for SL  between L1,L3 and L2,L4 is not “real”. It must be related with the TP system. (1 TP connector for L2,L4 the other one for L1,L3) A global T0 per Layer required

SL  Vd (  m/ns) Resol (  m) SL  Vd (  m/ns) Resol (  m) ROB

11  22 SL’s  1 and  2 : All values inside of + 1ns SL  : ~ difference of ~5ns between left and right Resolution (left or right) = ~200  m Global shift between L1,L3 and L2,L4 ~ 140  m

( x ) = 42.3 mm Nominal Value: 42 mm Shift respect to nominal ~ 300  m (inside tolerances)

Eff=4L/(3L+4L) (For the central part of the cell) L1 L2 L3 L4    L1 L2 L3 L4    ROB Efficiency > 99.5 %

Selection of events with good track (4L) on  and  And looking for track (3 or 4 L) on . Beam postion on  : Eff= 97 %Eff= 92 % There is about 5 % of events lost on CAEN data

L1 L2 L3 L4       ’s ABS:10) Efficiency : Resolution: not   217  m (217  m)  258  m (254  m)  229  m (217  m) Not degradation on resolution

 25ns LHC beam-like) In a first look the values of resolution, drift velocity and efficiency (computed as L4/(L4+L3)) Are compatibles with the previous one.

Time Hits Trig2 Trig 1 Trig 2 Overlaping of events: Overlaping of events: The TDC is recording hits all the time. Trigger time is recorded in an dedicate TDC channel When a trigger arrives a window is open looking for hits. Time window is bigger than the maximum drift velocity and therefore bigger than the time between triggers. For each muon trigger given by the scintillators, we will have ALL the hits associated to this muon, and perhaps SEVERAL hits associated to the Previous/next muon Hits Trig1  25ns LHC beam-like)

 25ns) Event N: Trigger chan: 2 hits found: Time1=280ns Time2=430 Hits Found: Cell Time Tim- Time- -T0G RAW TC40L1 -Ttrigger C40L C40L C40L C40L C42L C42L C41L C41L Trigger chan: 2 hits found: Time1=130ns Time2=280 Hits Found: Cell Time Tim- Time- -T0G RAW TC40L1 -Ttrigger C40L C40L C40L C40L C42L C42L C41L C41L C42L Event N+1: (T1+T2+T3+T4)/2 = 373 (T1+T2+T3+T4)/2 = 686 (T1+T2+T3+T4)/2 = 72 (T1+T2+T3+T4)/2 = 386  passing through Cells 40 must correspond to the event N  passing through Cells must correspond to the event N+1 The additional hit on C42L4 appears on the event N+2 correspond to the next trigger

Chan (1/0.2)Hz NO  ABS100  ABS5 RPC OFF No  : 50Hz 0.05 Hz/cm 2 (~2xISR value)  ABS100: 2.5 Hz/cm 2  ABS5 : 45 Hz/cm 2

Preliminary results from the analysis of the test beam data shows a good performance of the MB2 chamber at GIF. ROB electronics has been tested and validated