-- ChristopheClement - 19 Mar 2006

Response to electrons vs tile number (beam at 90 degrees)

Here we want to see if the electron response Cem is higher when shooting for example in the tile in the middle of a cell, or if a general pattern can be seen, that would be the result of vaying shower containment and varying light attenuation depending on the tile location, size and fiber length...

• Cem vs tile no. in module JINR01 @ 20 Gev:
  

• Cem vs tile no. in module JINR01 @ 180 Gev:
  

• Cem vs tile no. in module JINR34 @ 20 Gev:
  

• Cem vstile no. in module JINR34 @ 180 Gev:
  

Shower profiles

The goal here is to see if we can translate the Cem electron calibration constants b/w the numbers obtained at 20 degrees and at 90 degrees in the A10 cells at the corner of the module. Still ongoing...

Using Geant 4 simulation of standalone Tile Cal test beam I extract the following shower profiles for 20 degrees beam, into the middle of A10 cells.

	20 Gev	100 Gev	180 Gev
tile row 1		15.4+/-0.3
tile row 2		47.7+/-0.3
tile row 3		28.7+/-0.3
tile row 4		8.6+/-0.2
tile row 5		<0.5 %

For more details (like 'display' of the shower) and plots of energy deposited per tile row, look at ShowerProfiles

(in progress: extract shower shapes at 20/90 degrees and 20/180GeV and see if we can go from Cem @20degrees <-> Cem @90 degrees from electron data and shower shapes...) Note: obtained on tilecal standalone simulated with G4, test electron beam entering from the left. Coordinates: z is parallelle to the page (and parallelle to the LHC beam) x is radial outward from LHC beam (and to the right of the page) and y upward wrt to the module and to the page. Each point shows corresponds to some energy deposition in the sensitive material ie the tiles, that is why one can see the tile structure on these plots. Amount of leakage into B cells increases for higher energy.

• 180 Gev electrons @ 0 degrees in A -10 cell

• 180 Gev electron @ 20 degrees in A -10 cell

• 20 Gev electron @ 0 degrees in A -10 cell

• 20 Gev electron @ 20 degrees in A -10 cell

Correlation of electron response at 20, 100 and 180 GeV

We can plot the average per module electron response Cem obtained with 20 GeV electrons versus Cem in the same cell, but at another energy. The plots below show the correlations, which give an idea of the systematic effects that might affect Cem. (eg. different energies means different shower containment in the cell, systematic in the extraction procedure for Cem,...).

• Cem Correlations module JINR01:
  

• Cem Correlations module JINR34:
  

As a rule of thumb I estimate the systematic error on Cem as the largest RMS of

Cem(energy1,angle) -Cem(energy2,same angle)

where for some modules there are 3 energies available while 2 for others and sometimes 2, and either 1 or 2 angles.

module	syst error on Cem
JINR01	0.0162252
JINR34	0.0110144
JINR27	0.0107714
IFA15	0.000887328
IFA24	0.00217961
ANL08	0.0135542
IFA59	0.0134887
ANL27	0.00648002
IFA09	0.0170213

Correlation b/w Cesium response in modules and Cem

20 degree test beam data and A-cells

• Distributions of cesium responses in various modules: The cesium runs used here were taken during testbeam periods. The final Cesium runs are used here (ie after final setting of HV)

There are 3 tile rows per cell, 2 pmts per cell so we have 6 entries cell. In LB modules there are 10 cells--> 60 entries and 5 cells per EB module so 30 entries. For the moment I have only Cem for both LB+ and LB- together (I would need LB+ and LB- separately) while the Cs runs are per half LB module. So I chose B- for LB, but there is no significant difference use B+.

From these distributions I can extract the per-module mean Cs response and the RMS of the response.

• From the plot above we have the mean Cs response and RMS of Cs response and we can plot them as function of the mean electron calibration constant per module.

• Deviation of the average per-module electron response (20 GeV) from mean response (1.154 pC/GeV) versus per-module RMS of Cs response:

• Average per-module electron response (@ 20 GeV) versus the per-module RMS of Cs response:
  

• Deviation of the average per-module electron response (@ 20 GeV) versus the per-module mean Cs response:
  

• Average per-module electron response (@ 20 GeV) versus the per-module mean of Cs response: