CLAS12 R1 S1 QA

HV burn in

Begin burn in after at least 3 volume changes.

File:High Voltage Region 1 Sector 1 data.xls

Step 1: Set Voltage to 50 volts on all channels. Probe HVB to be sure that all sense, field, and guard wires have a voltage. (You should set current threshold to 10 microAmps on the HV supply)

Step 2: While monitoring the current, ramp the HV to the following

G:F:S= 525,-700,700

Step 3: Begin to take data recording the time and sense wire current as you ramp up the sense wire HV to 1400 volts while restricting the current draw to less than 10 micraAmps.

keep current under 10 micro amps while moving sense voltage up to 1400

Measured Sense wire output

CLAS12_R1_S1_QA_wireOut

Cosmic Runs

CLAS12R1_CosmicTestStand

3811

Cosmic rays were used to measure drift chamber time spectra with respect to scintillators placed above and below the drift chambers (more details are at the wiki location CLAS12R1_CosmicTestStand)

Fig 23 from "The CLAS drift chamber system", M. Mestayer, et. al., NIM A, Volume 449, Issues 1–2, 11 July 2000, Pages 81–111	cosmic run from 1/10 - 1/14. Signal cable 4 (ch. 48-63). 16 channels with leading edge discriminators (-80 mV, 100 ns pulse width).	Cosmics runs with lower discriminator thresholds	Chamber 4 at JLab

R3811_TDCspectra

3833

R3833_TDCspectra

R3833_Efficiency1

3834

R3834_TDCspectra

Cosmic measurements

Run #	Date	Description
3806	1/10/13	3 hour cosmic run, 16 channels with leading edge discriminators (-80 mV, 100 ns pulse width)
3809	1/10/13	cosmic run on 1/10. Signal cable 4 (ch. 48-63). 16 channels with leading edge discriminators (-80 mV, 100 ns pulse width).
3810	1/10/13	cosmic run from 1/10 - 1/14. Signal cable 4 (ch. 48-63). 16 channels with leading edge discriminators (-80 mV, 100 ns pulse width). Scintillator paddle F1/F2 on table above Sector 1, paddle I1/I2 below.
3811	1/10/13
3831	2/1/13	Changed disciminator from 80 mV to 60 mV, We improved the window, installed HV & STB boards, purged and started taking cosmic data again, DC is sandwhiched between 2 scints with PMTs aligned (PMT on only one end of Scint is turned on)
3833	2/4/13	Changed disciminator from 60 mV to 30 mV
3834	2/11/13	Changed disciminator from 30 mV to 60 mV
3835	2/19/13	Changed disciminator from 60 mV to 20 mV

Readout Map

Wire		PostAmpOut (CH 1-96)	TDC Channel
L	W
5	1	1	1
3	1	2	2
1	1	3	3
6	1	4	4
4	1	5	5
2	1	6	6
5	2	7	7
3	2	8	8
1	2	9	9
6	2	10	10
4	2	11	11
2	2	12	12
5	3	13	13
3	3	14	14
1	3	15	15
6	3	16	16
4	3	17	17
2	3	18	18
5	4	19	19
3	4	20	20
1	4	21	21
6	4	22	22
4	4	23	23
2	4	24	24
5	5	25	25
3	5	26	26
1	5	27	27
6	5	28	28
4	5	29	29
2	5	30	30
5	6	31	31
3	6	32	32
1	6	33	33
6	6	34	34
4	6	35	35
2	6	36	36
5	7	37	37
3	7	38	38
1	7	39	39
6	7	40	40
4	7	41	41
2	7	42	42
5	8	43	43
3	8	44	44
1	8	45	45
6	8	46	46
4	8	47	47
2	8	48	48
5	9	49	49
3	9	50	50
1	9	51	51
6	9	52	52
4	9	53	53
2	9	54	54
5	10	55	55
3	10	56	56
1	10	57	57
6	10	58	58
4	10	59	59
2	10	60	60
5	11	61	61
3	11	62	62
1	11	63	63
6	11	64	64
4	11	65	65
2	11	66	66
5	12	67	67
3	12	68	68
1	12	69	69
6	12	70	70
4	12	71	71
2	12	72	72
5	13	73	73
3	13	74	74
1	13	75	75
6	13	76	76
4	13	77	77
2	13	78	78
5	14	79	79
3	14	80	80
1	14	81	81
6	14	82	82
4	14	83	83
2	14	84	84
5	15	85	85
3	15	86	86
1	15	87	87
6	15	88	88
4	15	89	89
2	15	90	90
5	16	91	91
3	16	92	92
1	16	93	93
6	16	94	94
4	16	95	95
2	16	96	96

Measurements with source

4/20/12 1hour counts:

SL2 HVB1 Column 18 Row 5

-With source 14459 pulses/1502 sec

4/23/12 SL1 HVB7 column 203 row 4

-With source 50681 pulses/3760 sec.

4/25/12 1 hour counts:

SL2 HVB4 Column 118 row 5

- Without source: 33145 pulses/3610 Sec.

- With source(CS-137):38262 pulses/3600 Sec.

- Without source: 37548 pulses/3715 Sec.

Preamp voltage:5V

Background measurements

HV off 4/5/12 Background counts:

27 pulses/61806 Sec.

SL2 Column 132 row 2

Preamp voltage 6.3V

Discriminator threshold 46mV

Preamp on= 6.3

4/9/12: Back ground count measurements

4531 counts/69564 seconds

2044 counts/24620 seconds

4/10/12 Background counts:

3 pulses/ 74500 sec.

SL1 HVB7 Column 196 Row 2

Preamp voltage 6.3 V

Discriminator threshold 46mV

4/16/12 Background counts:

280 pulses/245850 sec

SL1 HVB7 column 226 row 2

preamp voltage 5V

Discriminator threshold 46mV

4/17/12 Background counts:

6 pulses/62407 sec

SL2 HVB7 column 226 row 8

preamp voltage 5V

discriminator threshold 46mV

4/20/12 Background counts:

63 pulses/ 71724 Sec.

SL1 HVB7 column 226 row 8

Preamp voltage 5V

Discriminator threshold 46mV

4/23/12 Background counts:

41078 pulse/ 245104 sec.

SL1 HVB7 Column 203 Row 4

Preamp voltage 5V

Discriminator threshold 46mV

Cosmic measurements

4/24/12 Cosmic count:

SL1 HVB1 Column 3 Row 10

14534 pulses/11547 sec.

Preamp voltage 5V

4/26/12 Overnight Cosmic pulse count:

SL2 HVB4 Column 118 Row 5

53122 pulses/49793 Sec.

Preamp voltage 5V

CLAS12_R1