Calibration in energy

Calibration

file = /star/data03/daq/2005/049/st_physics_6049030_raw_1020001.daq
cuProductionMinBias
- Here is a link to my previous study for the calibration : files from where I took the calibration values, and the first attempts are shown

For all Ladders

ladder 1 without calibration	ladder 1 with calibration : 16/16 calibration values

ladder 2 without calibration	ladder 2 with calibration no calibration

ladder 3 without calibration	ladder 3 with calibration 13/16 calibration values

ladder 4 without calibration	ladder 4 with calibration 15/16 calibration values

ladder 5 without calibration	ladder 5 with calibration 15/16 calibration values

ladder 6 without calibration	ladder 6 with calibration 16/16 calibration values

ladder 7 without calibration	ladder 7 with calibration no calibration

ladder 8 without calibration	ladder 8 with calibration no calibration

ladder 9 without calibration	ladder 9 with calibration 15/16 calibration values

ladder 10 without calibration	ladder 10 with calibration 12/16 calibration values

ladder 11 without calibration	ladder 11 with calibration 15/16 calibration values

ladder 12 without calibration	ladder 12 with calibration 16/16 calibration values

ladder 13 without calibration	ladder 13 with calibration 14/16 calibration values

ladder 14 without calibration	ladder 14 with calibration 16/16 calibration values

ladder 15 without calibration	ladder 15 with calibration 14/16 calibration values

ladder 16 without calibration	ladder 16 with calibration 9/16 calibration values

ladder 17 without calibration	ladder 17 with calibration 16/16 calibration values

ladder 18 without calibration	ladder 18 with calibration 15/16 calibration values

ladder 19 without calibration	ladder 19 with calibration 11/16 calibration values

ladder 20 without calibration	ladder 20 with calibration 14/16 calibration values

I indicate in blue the number of calibration values we have for each ladders, as there is 16 wafers per ladders. It may explain the difference in the efficiency in the calibration
For exemple, ladder 3 has 3 wafers which don't have calibrations values and ladder 4 has only 1 : the difference in the efficiency between these two ladders :

ladder 3 : before the calibration , deviation : < pulseN - pulseP > = - 10.95 ADC
ladder 3 : after the calibration , deviation : < pulseN - pulseP > = - 3.062 ADC
ladder 4 : before the calibration , deviation : < pulseN - pulseP > = - 4.966 ADC
ladder 4 : after the calibration , deviation : < pulseN - pulseP > = - 0.230 ADC

But even we don't reach a deviation equal to 0 for the ladder 3, the calibration is quite efficient because we correct this ladder by almost 7 ADC.
There are still point to improve and investigate :

Obtain the calibration values for all the wafers
Obtain the calibration values for ladder 1,7 and 8
Understand ladder 14 where the calibration don't improve the matching and makes it in the opposite way
Understand the behaviour of ladder 20

Results for 1 wafer especially

The black lign shows the perfect matching between the two sides : one can see that the calibration, for one wafer particularly, seems to be efficient.


Picture 1 : without calibration	Picture 2 : with calibration

Consequences of the Calibration

When the geometrical overlap of the clusters leads to ambiguous hits, the charge matching (same quantities of charges is collected on bothsides of the wafer) is used : (- Star note 0427 : Silicon Strip Detector Reconstruction Chain for the STAR Experiment.
Ambiguities arise for the package 2-2B so with the calibration, we hope to better reconstruct those cases .

Case	1-1	(1-2)A	(1-2)AS	(1-3)A	(1-3)AS	(2-2)A	(2-2)AP	(2-2)B	(2-3)A	(2-3)AP	(3-3)A
Case	0	1	2	3	4	5	6	7	8	9	10	total
Number of hits without the calibration	76075	3392	3040	1620	492	746	780	3052	1331	592	1224	92344
Number of hits with the calibration	76035	3402	3024	1641	486	748	782	3080	1295	624	1230	92347
Diff	-40	+10	-16	+21	-6	+2	+2	+28	-36	+32	+6	+3

Jonathan Bouchet

Last modified: febuar, 10