PePPO 05302012

Runlist

	Signal channel	HV dac	HV (V)	readback
Run No.	Run Time (s)	e- Current (nA)	Converter Target	Mode	DAQ Rate (Hz)	Chromox Target Position
5767	1566	1	1 mm thick W	positron		In
5768	1763	1	1 mm thick W	positron		Out
5774		1	1 mm thick W	positron	75	IN
5775		1	0.1 mm thick W	positron	75	IN
5776	1408	0.5	1 mm thick W	positron	75	In
5778	858	0.5	1 mm thick W	positron	50	Out
5779	1338	0.5	0.5 mm thick W	positron	50	In

Data Analysis

Calibration

https://positron.jlab.org/wiki/index.php/05232012_AnnihCntr_Calibration#Results

The calibration constants appear to have changed from

511/22230 for Annihlation Detector A1 to 511/29588 (ped subtracted)

511/18192 for Annihlation Detector A3 to 511/13706 (ped subtracted)

Fits to the peaks in run 5440 and 5441 gave the following results

Energy	A1 Channel	A3 Channel
0	40002	41709.5
511	69655.5	55603.8
1170	100127	71544.4
1270	104293	74165.3
1330	106243	75307.7

The high energy points overweight the linear fit for that energy region so I removed the 1179 and 1270 line from the fit. For A1 :

slope=50.1811 +/- 2.10455
y-intercept=41498.3 +/- 1894.94 
coerrelation coefficient=0.998246

For A3:

slope=25.3515 +/- 0.488128
y-intercept=42052.6 +/- 439.513 
coerrelation coefficient=0.999628

A fit biased by including three 1 MeV lines is

For A1

slope=45.8536 +/- 0.50289
y-intercept=46253.9 +/- 522.854 
coerrelation coefficient=0.999941

For A3

slope=24.3591 +/- 0.219479
y-intercept=43143.2 +/- 228.192 
coerrelation coefficient=0.999961

Target IN/OUT

Run 5767 & 5768

400 px

Run 5776 & 5778

Tight TDC cits TDC_A1-TDC_A3 < 5 nsec

Rates-vs- Converter thickness

Run No.	Run Time (s)	e- Current (nA)	Converter Target	Mode	Chromox Target Position
5774	489	1	1 mm thick W	positron	IN
5775	347	1	0.1 mm thick W	positron	IN
5776	1408	0.5	1 mm thick W	positron	In
5779	1338	0.5	0.5 mm thick W	positron	In

Run 5774 & 5775

Calibration: 60 Ch/keV

400 px

Run 5776 & 5779

Calibration: 60 Ch/keV

400 px

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