Difference between revisions of "CLAS12 R1 S1 QA"

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keep current under 10 micro amps  while moving  sense voltage up to 1400
 
keep current under 10 micro amps  while moving  sense voltage up to 1400
 +
 +
 +
=TDC cable test=
 +
 +
The following table shows the data for TDC testing input channels using the best cable (looks the other cables were tested to choose the best one) that has the range (32-63), the cable does not a signal in the three channels: 32,35,47.
 +
 +
{|border="1"  | cellpadding="20" cellspacing="0  class="wikitable"
 +
|-
 +
|Cable number range|| channels without hits
 +
|-
 +
|}
  
 
=Measured Sense wire output=
 
=Measured Sense wire output=
Line 25: Line 36:
 
==Sense Wire Scope pictures on DAQ machine==
 
==Sense Wire Scope pictures on DAQ machine==
  
 +
[[Summary of Testing Sense Wires for Scope Picture Signal]]
  
 
==Cosmic Runs==
 
==Cosmic Runs==
Line 372: Line 384:
 
{|border="1"  | cellpadding="20" cellspacing="0  class="wikitable"
 
{|border="1"  | cellpadding="20" cellspacing="0  class="wikitable"
 
|-
 
|-
|4146|| 5/29/13 || 58 mv Threshold, S:F:G=1500:-750:550 ,  everything connected back to order used in run 4142, run started at 08:12:35 on 5/29/13, ended at 07:39 on 6/10/13. 1,238,205 events , may have run low on ArC02 near the last day or two.
+
|'''4146'''|| 5/29/13 || 58 mv Threshold, S:F:G=1500:-750:550 ,  everything connected back to order used in run 4142, run started at 08:12:35 on 5/29/13, ended at 07:39 on 6/10/13. 1,238,205 events , may have run low on ArC02 near the last day or two.
 
|-
 
|-
 
|4147|| 6/10/13 || 58 mv Threshold, S:F:G=1350:-675:495 ,  run started at 10:13:23 on 6/10/13, ended at  on . Network went down and as a result DAQ failed after about 20k events.
 
|4147|| 6/10/13 || 58 mv Threshold, S:F:G=1350:-675:495 ,  run started at 10:13:23 on 6/10/13, ended at  on . Network went down and as a result DAQ failed after about 20k events.
 
|-
 
|-
|4148|| 6/11/13 || 58 mv Threshold, S:F:G=1350:-675:495 ,  run started at 07:44:11 on 6/11/13, ended at  on .  
+
|4148|| 6/11/13 || 58 mv Threshold, S:F:G=1350:-675:495 ,  run started at 07:44:11 on 6/11/13,  DAQ crashed after about 14k events with error message ..." Can not find container_admin"...
 +
|-
 +
|4153|| 6/12/13 || 58 mv Threshold, S:F:G=1350:-675:495 ,  run started at 13:35:25 on 6/12/13, ended at 17:30:45  on 6/13/13.  Internet outage expected after 6pm today
 +
|-
 +
|4154|| 6/14/13 || 58 mv Threshold, S:F:G=1250:-625:458 ,  run started at 08:55:07 on 6/14/13, ended at 7:39:16 on 6/17/13.  The ADB crate was turned off.
 +
|-
 +
|'''4155'''|| 6/17/13 || 58 mv Threshold, S:F:G=1250:-625:458 ,  run started at 07:40:43 on 6/17/13, ended at  on 6/20/21.  ISU network is going down for maintenance, '''Guard voltage may have been 489 when I looked to set the HV for run 4157 the readback showed 489 Volts.'''
 +
|-
 +
|'''4157'''|| 6/21/13 || 58 mv Threshold, S:F:G=1300:-650:473 ,  run started at 11:34:46 on 6/21/13, ended at 13:57 on 6/24/13.
 +
|-
 +
|4158|| 6/24/13 || 58 mv Threshold, S:F:G=1400:-700:509 ,  run started at 14:04:11 on 6/24/13, ended at 11:05  on 6/25/13. Error message at 15:38:48 on 6/25/13 said ER was not responding it seemed to recover but event number -vs- TDC had gaps for TDC ch 8-> 15, it looks like all the events came out in TDC ch 11 after the ER client recovered?, starting a new run
 +
|-
 +
|4159|| 6/25/13 || 58 mv Threshold, S:F:G=1400:-700:509 ,  run started at 11:06:05 on 6/25/13, ended at  11:12:55 on 6/26/13. ROC
 +
|-
 +
|4160|| 6/26/13 || 58 mv Threshold, S:F:G=1400:-700:509 ,  run started at 13:26:51 on 6/26/13, ER failed
 +
|-
 +
|4161|| 6/26/13 || 58 mv Threshold, S:F:G=1400:-700:509 ,  run started at 21:13:27 on 6/26/13, ended at 09:16:32 on 6/27/13, TDC40->TDC43 have events that are way out of time, restart run
 +
|-
 +
|4162|| 6/27/13 || 58 mv Threshold, S:F:G=1400:-700:509 ,  run started at 09:17:02 on 6/27/13, ended at  on TDC40->TDC43 still have events that are way out of time, APlatform:ERROR Lost connection to the container = daq2.physics.isu.edu_admin. 15:39:54 06/24
 +
|-
 +
|4163|| 6/27/13 || 58 mv Threshold, S:F:G=1400:-700:509 ,  run started at 09:17:02 on 6/27/13, ended at  on
 +
|-
 +
|4165|| 7/3/13 || 58 mv Threshold, S:F:G=1400:-700:509 ,  ADB cards were swapped to see if the out of time events in TDC ch 40->43 move to the channels in the other ADC, they did not, switch the cables back and check the ADC cables.
 +
|-
 +
|4166|| 7/5/13 || 58 mv Threshold, S:F:G=1400:-700:509 ,  swapped the ADB output cables such that ADB outputs in TDC chan 32->47 are now going into TDC channels 81->96.  The problems with ut of time hits moved with the ADC output cables.  The question now; Is it the cable, the connectors, or the TDC?
 +
|-
 +
|4168|| 7/22/13 || 58 mv Threshold, S:F:G=1400:-700:509 ,  out timing on channel 15,21,31 before swapped the ADB output cables 0-31 and 64->95
 +
|-
 +
|4168|| 7/22/13 || 58 mv Threshold, S:F:G=1400:-700:509 ,  out timing on channel 15,21,31 before swapped the ADB output cables 0-31 and 64->95
 +
|-
 +
|4173|| 08/04/13 || 58 mv Threshold, S:F:G=1400:-700:509 ,  out timing on channel: 11,15,16,18,21,23,25,27,31,80,82,85,86,88,89,90,91,92,95. The highest number of events: 96. Zero events: 0,74. Events less than 300: 8,9,10,12,13,14,24,26,29,30. Over timing on a specific event number interval:28,40,42,46,59,81,84,93.
 +
|-
 +
 
 +
 
 
|}
 
|}
  
  The network will be down Thursday (6/13) night until Friday morning.  Stop the DAQ Thursday at 5pm
+
  The network will be down Thursday (6/20) night until Friday morning.  Stop the DAQ Thursday at 5pm
  
 
=Readout Map=
 
=Readout Map=
Line 733: Line 778:
 
:x=TDC2row[TDCChannelNumber%6)];
 
:x=TDC2row[TDCChannelNumber%6)];
 
:y=(TDCChannelNumber/6+1)*(1+0.25*sin(PI/3)/(1+sin(PI/6)))=(TDCChannelNumber/6+1)*(1.14434);
 
:y=(TDCChannelNumber/6+1)*(1+0.25*sin(PI/3)/(1+sin(PI/6)))=(TDCChannelNumber/6+1)*(1.14434);
 +
 +
;if the layer number (X) is even then the Y position center needs to be shifted backward in the Y direction by
 +
:y[HitNumber]-=sin(PI/3)/(1+sin(PI/6));
  
 
The uncertainty in the position is
 
The uncertainty in the position is
Line 744: Line 792:
  
 
<pre>
 
<pre>
Col(X)    Row(Y)      Time
+
Layer(X)    Wire(Y)      Time
 
3(3)    6(7.26221)    1415
 
3(3)    6(7.26221)    1415
 
1(1)    6(7.26221)    1368
 
1(1)    6(7.26221)    1368
6(6)    6(7.26221)    1308
+
6(6)    6(6.42074)    1308
4(4)    6(7.26221)    1311
+
4(4)    6(6.42074)    1311
2(2)    6(7.26221)    1332
+
2(2)    6(6.42074)    1332
 
5(5)    7(8.47257)    1419
 
5(5)    7(8.47257)    1419
 
</pre>
 
</pre>
Line 756: Line 804:
 
A linear fit is performed assuming that the ionization event occurs in the center of the cell.  Later a drift time function should be used to offset each hit from the center according to the drift time function that uses the TDC measurement as an input.
 
A linear fit is performed assuming that the ionization event occurs in the center of the cell.  Later a drift time function should be used to offset each hit from the center according to the drift time function that uses the TDC measurement as an input.
  
Below is another event
 
  
[[File:A61113_TrackHit.png| 400 px]]
+
Below is the incident cosmic ray angle when only 6 hits occur in the chamber for run [[CLAS12_r4135]]
 +
 
 +
[[File:R4135_Angle_6hits.png | 200 px]]
 +
 
 +
 
 +
=Efficiency measurement=
 +
 
  
 +
[[Clas12_Carlos_eff]]
  
  
 
[[ CLAS12_R1]]
 
[[ CLAS12_R1]]

Latest revision as of 16:01, 14 December 2013

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


TDC cable test

The following table shows the data for TDC testing input channels using the best cable (looks the other cables were tested to choose the best one) that has the range (32-63), the cable does not a signal in the three channels: 32,35,47.

Cable number range channels without hits

Measured Sense wire output

CLAS12_R1_S1_QA_wireOut


Sense Wire Scope pictures on DAQ machine

Summary of Testing Sense Wires for Scope Picture Signal

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)


CLAS6 DCrawTDCspectrum.gif R3811 TDC51 Time.png R3831 3833TDC51 TimeL1W9.png JLabR1Chambr4.png
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

DChitDisplay 3831.png

R3811_TDCspectra

3833

R3833_TDCspectra

R3833_Efficiency1

3834

R3834_TDCspectra

Cosmic measurements

CLAS6 Drift Chamber NIM paper

File:NIM A 449 2000 pg81.pdf


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

Using ADB crate

(TDC1190[106]-TDC1190[104] = 3 ns) => PMT F1 - PMT I2 = Two PMTs that are on separate paddles and adjacent.

(TDC1190[106]-TDC1190[107] = 40 +/- 10 ns) => PMT F1 - PMT F2 = Two PMTs that are on the SAME paddle. Not sure why there is a 40 ns offset but the 10 ns wide range is because the paddles are about 70 cm long ( see CLAS12R1_CosmicTestStand#Scintillator_Timing_Studies)


TDC-CH# WIRE
104 PMT I2
106 PMT F1
107 PMT F2
00 U1 L2W1
01 U2 L4W1
02 U3 L6W1
03 U4 L1W1
04 U5 L3W1
05 U6 L5W1
06 U7 L2W2
07 U8 L4W2
08 U9 L6W2
09 U10 L1W2
10 U11 L3W2
11 U12 L5W3
12 U13 L2W3
13 U14 L4W3
14 U15 L6W3
15 U16 L1W3
16 U17 L3W3
17 U18 L5W3
18? U19 L2W4
19 U20 L4W4
20 U21 L6W4
21 U22 L1W4
22 U23 L3W4
23 U24 L5W4
24 U25 L2W5
25 U26 L4W5
26 U27 L6W5
27 U28 L1W5
28 U29 L3W5
29 U30 L5W5
30 U31 L2W6
31 U32 L4W6
32 U33 L6W6
33 U34 L1W6
34 U35 L3W6
35 U36 L5W6
36 U37 L2W7
37 U38 L4W7
38 U39 L6W7
39 U40 L1W7
40 U41 L3W7
41 U42 L5W7
42 U43 L2W8
43 U44 L4W8
44 U45 L6W8
45 U46 L1W8
46 U47 L3W8
47 U48 L5W8
48 U49 L2W9
49 U50 L4W9
50 U51 L6W9
51 U52 L1W9
52 U53 L3W9
53 U54 L5W9
54 U55 L2W10
55 U56 L4W10
56 U57 L6W10
57 U58 L1W10
58 U59 L3W10
59 U60 L5W10
60 U61 L2W11
61 U62 L4W11
62 U63 L6W11
63 U64 L1W11
64 U65 L3W11
65 U66 L5W11
66 U67 L2W12
67 U68 L4W12
68 U69 L6W12
69 U70 L1W12
70 U71 L3W12
71 U72 L5W12
72 U73 L2W13
73 U74 L4W13
74 U75 L6W13
75 U76 L1W13
76 U77 L3W13
77 U78 L5W13
78 U79 L2W14
79 U80 L4W14
80 U81 L6W14
81 U82 L1W14
82 U83 L3W14
83 U84 L5W14
84 U85 L2W15
85 U86 L4W15
86 U87 L6W15
87 U88 L1W15
88 U89 L3W15
89 U90 L5W15
90 U91 L2W16
91 U92 L4W16
92 U93 L6W16
93 U94 L1W16
94 U95 L3W16
95 U96 L5W16

Runlist Disc=100 mv

Run # Date Description
4008 4/11/13 set ADB threshold to 100 , installed all 6 STB connectors, key was on the left as you face the ADC crate. Two top PMTs and one bottom PMT were in coincidence. The rate was about 0.5 Hz. at 9:41 on 4/12/13 I observed no voltage coming out of the discriminator monitor, the fuses were NOT blown. Hits seemed to disappear in the data. I recycled the ADB crate power and saw 100 mV on the discriminator monitor. Start a new run 40009
4009 4/12/13 ADC threshold at 100 mV
4014 4/16/13 Removed cable from J10 connector on ADB crate and becan a cosmic run, the ROC & EB1 segfaulted after 57702 events
4082 4/17/13 first run with fully installed ADC crate & known map; ROC crashed after 5522 event around 20:53
4099 4/17/13 ROC & EB crash after 4702 events, restarted all processes prior to taking this data
4127 4/24/13 100 mv Threshold, S:F:G=1500:-750:550 ROC crashed because there was not enough memory for all the data, increased memory in the readoutlist R4127Histos
4128 4/24/13 run ended on 4/29 at 10:43,100 mv Threshold, S:F:G=1500:-750:550 re-centered scintillator based on occupancy plot from 4127, the event rate dropped after 2 hrs (event 5000) , TDC chan 32 -> 63 dropped out between event number 5000 and 360000, why did they start working?
4129 4/29/13 100 mv Threshold, S:F:G=1500:-750:550 , lost hits after 50000 events
4130 4/30/13 100 mv Threshold, S:F:G=1500:-750:550 , only 3, 16 channel ADB inputs are working (TDC channels 16->31, 64->95)
4131 5/1/13 100 mv Threshold, S:F:G=1500:-750:550 , Moved DC output connectors so the channels centered on the scintillator are on the working ADB inputs (ribbon cable 3 is on ADB input 2, cable 4 is on input 5, and cable 5 is on ADB input 6); Only ADB input 6 shows hits
4132 5/2/13 100 mv Threshold, S:F:G=1500:-750:550 , Moved DC output connectors so ribbon cable 2 is on ADB input 1, cable 5 is on input 4, and cable 6 is on ADB input 6, all others are unplugged
4134 5/3/13 100 mv Threshold, S:F:G=1500:-750:550 , Moved DC output connectors so ribbon cable 2 is on ADB input 3, cable 5 is on input 5, and cable 6 is on ADB input 6, all others are unplugged
4135 5/4/13 100 mv Threshold, S:F:G=1500:-750:550 , replaced preamp power supply, CLAS12_r4135
4136 5/6/13 100 mv Threshold, S:F:G=1500:-750:550 , CLAS12_r4136
4138 5/8/13 100 mv Threshold, S:F:G=1500:-750:550 , CLAS12_r4138,internet failed and lost connection to rocdaq1 after 479752 events on 5/13/13 at 6:11 am

Runlist Disc=30 mv

4139 5/13/13 30 mv Threshold, S:F:G=1500:-750:550 CLAS12_r4139, run started at 9:05:57 on 5/13 and ended at 12:52:44 on 5/20


Runlist Disc=58 mv

4140 5/20/13 58 mv Threshold, S:F:G=1280:-750:550 CLAS12_r4140, run started at 13:57:34 on 5/20 and ended at 16:43:39 on 5/20
4141 5/20/13 58 mv Threshold, S:F:G=1500:-750:550 CLAS12_r4141, run started at 16:47:48 on 5/20 and ended , TDC channels 62->76 were failing after event 80000 and then seemed to turn on and off for a while
4142 5/20/13 58 mv Threshold, S:F:G=1500:-750:550 , run started at , TDC channels 62->76 were failing they seemed to turn on and off for a while
4143 5/27/13 58 mv Threshold, S:F:G=1500:-750:550 , swapped last two inputs to ADB board for channels 64->96. Check if hits start failing on ch 80->96
4145 5/28/13 58 mv Threshold, S:F:G=1500:-750:550 , swapped middle inputs between two ADC boards (ch 17->32 echanged with ch 64->80), all channels were working??? lets switch it back, perhaps connector had bad connection?
4146 5/29/13 58 mv Threshold, S:F:G=1500:-750:550 , everything connected back to order used in run 4142, run started at 08:12:35 on 5/29/13, ended at 07:39 on 6/10/13. 1,238,205 events , may have run low on ArC02 near the last day or two.


HV-vs- Efficiency

Keep the discriminator constant and change the HV.

The HV should stay at the ratios of S:F:G=1:0.5:4/11

4146 5/29/13 58 mv Threshold, S:F:G=1500:-750:550 , everything connected back to order used in run 4142, run started at 08:12:35 on 5/29/13, ended at 07:39 on 6/10/13. 1,238,205 events , may have run low on ArC02 near the last day or two.
4147 6/10/13 58 mv Threshold, S:F:G=1350:-675:495 , run started at 10:13:23 on 6/10/13, ended at on . Network went down and as a result DAQ failed after about 20k events.
4148 6/11/13 58 mv Threshold, S:F:G=1350:-675:495 , run started at 07:44:11 on 6/11/13, DAQ crashed after about 14k events with error message ..." Can not find container_admin"...
4153 6/12/13 58 mv Threshold, S:F:G=1350:-675:495 , run started at 13:35:25 on 6/12/13, ended at 17:30:45 on 6/13/13. Internet outage expected after 6pm today
4154 6/14/13 58 mv Threshold, S:F:G=1250:-625:458 , run started at 08:55:07 on 6/14/13, ended at 7:39:16 on 6/17/13. The ADB crate was turned off.
4155 6/17/13 58 mv Threshold, S:F:G=1250:-625:458 , run started at 07:40:43 on 6/17/13, ended at on 6/20/21. ISU network is going down for maintenance, Guard voltage may have been 489 when I looked to set the HV for run 4157 the readback showed 489 Volts.
4157 6/21/13 58 mv Threshold, S:F:G=1300:-650:473 , run started at 11:34:46 on 6/21/13, ended at 13:57 on 6/24/13.
4158 6/24/13 58 mv Threshold, S:F:G=1400:-700:509 , run started at 14:04:11 on 6/24/13, ended at 11:05 on 6/25/13. Error message at 15:38:48 on 6/25/13 said ER was not responding it seemed to recover but event number -vs- TDC had gaps for TDC ch 8-> 15, it looks like all the events came out in TDC ch 11 after the ER client recovered?, starting a new run
4159 6/25/13 58 mv Threshold, S:F:G=1400:-700:509 , run started at 11:06:05 on 6/25/13, ended at 11:12:55 on 6/26/13. ROC
4160 6/26/13 58 mv Threshold, S:F:G=1400:-700:509 , run started at 13:26:51 on 6/26/13, ER failed
4161 6/26/13 58 mv Threshold, S:F:G=1400:-700:509 , run started at 21:13:27 on 6/26/13, ended at 09:16:32 on 6/27/13, TDC40->TDC43 have events that are way out of time, restart run
4162 6/27/13 58 mv Threshold, S:F:G=1400:-700:509 , run started at 09:17:02 on 6/27/13, ended at on TDC40->TDC43 still have events that are way out of time, APlatform:ERROR Lost connection to the container = daq2.physics.isu.edu_admin. 15:39:54 06/24
4163 6/27/13 58 mv Threshold, S:F:G=1400:-700:509 , run started at 09:17:02 on 6/27/13, ended at on
4165 7/3/13 58 mv Threshold, S:F:G=1400:-700:509 , ADB cards were swapped to see if the out of time events in TDC ch 40->43 move to the channels in the other ADC, they did not, switch the cables back and check the ADC cables.
4166 7/5/13 58 mv Threshold, S:F:G=1400:-700:509 , swapped the ADB output cables such that ADB outputs in TDC chan 32->47 are now going into TDC channels 81->96. The problems with ut of time hits moved with the ADC output cables. The question now; Is it the cable, the connectors, or the TDC?
4168 7/22/13 58 mv Threshold, S:F:G=1400:-700:509 , out timing on channel 15,21,31 before swapped the ADB output cables 0-31 and 64->95
4168 7/22/13 58 mv Threshold, S:F:G=1400:-700:509 , out timing on channel 15,21,31 before swapped the ADB output cables 0-31 and 64->95
4173 08/04/13 58 mv Threshold, S:F:G=1400:-700:509 , out timing on channel: 11,15,16,18,21,23,25,27,31,80,82,85,86,88,89,90,91,92,95. The highest number of events: 96. Zero events: 0,74. Events less than 300: 8,9,10,12,13,14,24,26,29,30. Over timing on a specific event number interval:28,40,42,46,59,81,84,93.
The network will be down Thursday (6/20) night until Friday morning.  Stop the DAQ Thursday at 5pm

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


Primitive Tracking

Linfit to layer -vs- y distance

The staggered layering of the cells in a single drift chamber super layer results in cells that are offset from each other by 30 degrees (PI/6). Below is a event illustrating the observation of ionization signals observed by 6 of the 96 instrumented wires caused by the passage of a cosmic ray.

A coordinate system is established which defines the X-direction along the depth of the superlayer and the Y-direction along the endplate of the chamber. The chamber is facing towards the sky so cosmic rays may enter the front face of a chamber. The location of the cells, with this coordinate system, may be determined using the equations below along with the row and column of the hit.

TDC2row[]={5,3,1,6,4,2};
x=TDC2row[TDCChannelNumber%6)];
y=(TDCChannelNumber/6+1)*(1+0.25*sin(PI/3)/(1+sin(PI/6)))=(TDCChannelNumber/6+1)*(1.14434);
if the layer number (X) is even then the Y position center needs to be shifted backward in the Y direction by
y[HitNumber]-=sin(PI/3)/(1+sin(PI/6));

The uncertainty in the position is

DeltaX=1/sqrt(12);
DeltaY=sin(PI/3)/(1+sin(PI/6))/sqrt(3);

TDCChannelNumber is used to locate the row and column of the wire that saw an ionization signal.

61113 TrackHit.png

Layer(X)    Wire(Y)      Time
3(3)    6(7.26221)    1415
1(1)    6(7.26221)    1368
6(6)    6(6.42074)    1308
4(4)    6(6.42074)    1311
2(2)    6(6.42074)    1332
5(5)    7(8.47257)    1419


A linear fit is performed assuming that the ionization event occurs in the center of the cell. Later a drift time function should be used to offset each hit from the center according to the drift time function that uses the TDC measurement as an input.


Below is the incident cosmic ray angle when only 6 hits occur in the chamber for run CLAS12_r4135

R4135 Angle 6hits.png


Efficiency measurement

Clas12_Carlos_eff


CLAS12_R1