Difference between revisions of "GEM and Mini Prototype DC Cosmics Run"
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|7 || 3 || 30 || 14(not connected) | |7 || 3 || 30 || 14(not connected) | ||
|} | |} | ||
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== Electronics== | == Electronics== | ||
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==HV Settings S:F:G=1400:-700:980== | ==HV Settings S:F:G=1400:-700:980== | ||
+ | |||
+ | {| border="1" |cellpadding="20" cellspacing="0 | ||
+ | |Discriminator Threshold On Metalica || Run Length(sec) || Metalica Sense Wire 4 # of events || M4 events/hr || P4 events/hr | ||
+ | |- | ||
+ | | Noise + 10 mV =170 mV || 108 || 107 || 3566.7 || | ||
+ | |- | ||
+ | | || 102 || 121 || 4270.6 || | ||
+ | |- | ||
+ | | || 91 || 106 || 4193.4 || | ||
+ | |- | ||
+ | | 130 mV || 10 || 110 || || | ||
+ | |- | ||
+ | | || 11 || 109 || || | ||
+ | |- | ||
+ | | || 12 || 117 ||3.68e+4 <math>\pm</math> 2000 || | ||
+ | |- | ||
+ | | 150 mV || 879 || 1626 || || | ||
+ | |- | ||
+ | | || 193 || 304 || || | ||
+ | |- | ||
+ | | || 87 || 158 || 6.3e+3 <math>\pm</math> 440 || 399 <math>\pm</math> 81 | ||
+ | |- | ||
+ | | 250 mV || 338 || 316 || || | ||
+ | |- | ||
+ | | || 88 || 91 || || | ||
+ | |- | ||
+ | | || 178 || 171 || 3.5e+3 <math>\pm</math> 151 || 433 <math>\pm</math> 44 | ||
+ | |- | ||
+ | | 350 mV || 203 || 152 || || | ||
+ | |- | ||
+ | | || 185 || 118 || || | ||
+ | |- | ||
+ | | || 182 || 154 || 2.7e+3 <math>\pm</math>306 || 394 <math>\pm</math> 71 | ||
+ | |- | ||
+ | | 450 mV || 245 || 133 || || | ||
+ | |- | ||
+ | | || 733 || 405 || || | ||
+ | |- | ||
+ | | || 360 || 181 || 1.9e+3 <math>\pm</math>76 || 470 <math>\pm</math> 89 | ||
+ | |- | ||
+ | | 550 mV || 238 || 102 || || | ||
+ | |- | ||
+ | | || 184 || 91 || || | ||
+ | |- | ||
+ | | || 175 || 89 || 1.7e+3 <math>\pm</math>126 || 382 <math>\pm</math> 75 | ||
+ | |- | ||
+ | | 650 mV || 409 || 108 || || | ||
+ | |- | ||
+ | | || 578 || 150 || || | ||
+ | |- | ||
+ | | || 313 || 95 || 9.9e+2 <math>\pm</math>71 || 300 <math>\pm</math> 81 | ||
+ | |- | ||
+ | | 750 mV || 497 || 100 || || | ||
+ | |- | ||
+ | | || 588 || 135 || || | ||
+ | |- | ||
+ | | || 394 || 82 || 7.7e+2 <math>\pm</math>43 || 285 <math>\pm</math> 24 | ||
+ | |} | ||
{| border="1" |cellpadding="20" cellspacing="0 | {| border="1" |cellpadding="20" cellspacing="0 | ||
Line 518: | Line 575: | ||
[[Image:NoiseLevelOnMetalica_HV500V.png|350px]][[Image:500Volts_DiscriminatorThreshold_vs_Rate_for_Metalica.jpg|350px]] | [[Image:NoiseLevelOnMetalica_HV500V.png|350px]][[Image:500Volts_DiscriminatorThreshold_vs_Rate_for_Metalica.jpg|350px]] | ||
− | |||
+ | |||
+ | == Plateau measurement when VPI gain = x10 and Disc thresh = 80 mV== | ||
The above plateau measurements were done using the UVA splitter. In addition to cross talk, the splitter also increased the noise level. About 70 mV out of 140 mV of noise is due to the splitter. If the DC output goes directly into the VPI post amp the noise level goes down to about 70 mV. A grounding strap to the DC preamp power supply will decrease this noise to below 40 mV. | The above plateau measurements were done using the UVA splitter. In addition to cross talk, the splitter also increased the noise level. About 70 mV out of 140 mV of noise is due to the splitter. If the DC output goes directly into the VPI post amp the noise level goes down to about 70 mV. A grounding strap to the DC preamp power supply will decrease this noise to below 40 mV. | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
HV settings on Metalica are following S:F:G = 1300:-650:910 | HV settings on Metalica are following S:F:G = 1300:-650:910 | ||
Line 538: | Line 590: | ||
| || 30 || 92 || || 31 || 2967 | | || 30 || 92 || || 31 || 2967 | ||
|- | |- | ||
− | | || 34 || 99 || | + | | || 34 || 99 || 10825<math> \pm</math> 245 || 32 || 3096 |
|- | |- | ||
| 1300:-650:910 || 110 || 100 || || 108 || 925 | | 1300:-650:910 || 110 || 100 || || 108 || 925 | ||
Line 544: | Line 596: | ||
| || 140 || 109 || || 170 || 641 | | || 140 || 109 || || 170 || 641 | ||
|- | |- | ||
− | | || 145 || 102 || || 139 || 774 | + | | || 145 || 102 || 2869 <math>\pm</math> 306 || 139 || 774 |
|- | |- | ||
| 1200:-600:840 || 929 || 121 || || 972 || 124 | | 1200:-600:840 || 929 || 121 || || 972 || 124 | ||
Line 550: | Line 602: | ||
| || 722 || 114 || || 819 || 139 | | || 722 || 114 || || 819 || 139 | ||
|- | |- | ||
− | | || 950 || 102 || || 967 || 106 | + | | || 950 || 102 || 475 <math>\pm</math> 74 || 967 || 106 |
|- | |- | ||
− | | 1100:-550:770 || 2142 || 29 || | + | | 1100:-550:770 || 2142 || 29 || 49 <math>\pm</math> 0.2 || 2252 || 13 |
|- | |- | ||
− | | || || || || | + | | 700:-350:490 || 73329 || 1572 || 77 <math>\pm</math> 0.02 || 74782 || 21 |
+ | |- | ||
+ | | 500:-250:350 || 217503 || 4231 || 70 <math>\pm</math> 0.02 || 467034 || 9 | ||
+ | |} | ||
+ | |||
+ | |||
+ | I am confident that below 1200 Volts there is just noise, | ||
+ | If there is a pulse the rate cant be approximately 7 events/hr. | ||
+ | |||
+ | [[Image:HighVoltageonSenseWire_vs_Rate_for_Plastika.jpg|400px]] | ||
+ | |||
+ | ==Scint coinc Plateau measurement using 1 DC== | ||
+ | |||
+ | Now that we may have our cross talk problems gone and the noise reduced lets try to measure the plateaus again using 2 scintillators in coincidence . | ||
+ | |||
+ | |||
+ | ===Connector Tables=== | ||
+ | |||
+ | ====For Metalica==== | ||
+ | |||
+ | {| border="1" |cellpadding="20" cellspacing="0 | ||
+ | | Metalica Sense Wire # || VPI PostAmplifier Output(ADC && TDC) || ADC Channel# (VME) || TDC Channel# (VME) | ||
+ | |- | ||
+ | |1 || 8 || 12 || 14 | ||
+ | |- | ||
+ | |2 || 7 || || 8 | ||
+ | |- | ||
+ | |3 || 6 || || 9 | ||
+ | |- | ||
+ | |4 || 5 || 1 || 10 | ||
|- | |- | ||
− | | | + | |5 || 4 || || 12 |
|- | |- | ||
− | | | + | |6 || 3 || || 11(not used) |
|- | |- | ||
− | | || || || | + | |7 || 1 || || 13 |
+ | |} | ||
+ | |||
+ | ====For Plastika==== | ||
+ | |||
+ | {| border="1" |cellpadding="20" cellspacing="0 | ||
+ | | Plastika Sense Wire # || VPI PostAmplifier Output(ADC && TDC) || ADC Channel# (VME) ???? || TDC Channel# (VME) | ||
|- | |- | ||
− | | | + | |1 || 16 || 18 || 1 |
|- | |- | ||
− | | | + | |2 || 15 || 20 || 2 |
|- | |- | ||
− | | | + | |3 || 14 || 22 || 3 |
|- | |- | ||
− | | | + | |4 || 13 || 24 || 4 |
|- | |- | ||
− | | | + | |5 || 12 || 26 || 5 |
|- | |- | ||
− | | | + | |6 || 11 || 28 || 7(not used) |
|- | |- | ||
− | | | + | |7 || 10 || 30 || 6 |
|} | |} | ||
+ | |||
+ | |||
+ | ===24-04-2009=== | ||
+ | |||
+ | The HV settings on Metalica and Plastika are following: S:F:G=1350:-675:945. Metalica is placed between two scintillators. As a trigger and gate the coincidence pulse from PMTs is used. Only sense wire # 1 and # 4 of metalica are connected to the ADC and TDC of VME crator. | ||
=Experimental Setup for tracking tests= | =Experimental Setup for tracking tests= | ||
Line 587: | Line 679: | ||
[http://wiki.iac.isu.edu/index.php/Mini-prototype] Go back | [http://wiki.iac.isu.edu/index.php/Mini-prototype] Go back | ||
[[Mini-prototype]] | [[Mini-prototype]] | ||
+ | |||
+ | [http://wiki.iac.isu.edu/index.php/User_talk:Didbtama Go Back] |
Latest revision as of 05:06, 8 December 2012
Experimental Setup for efficiency tests
Connector Tables
For Metalica
Metalica Sense Wire # | VPI PostAmplifier Output(ADC && TDC) | ADC Channel# (VME) | TDC Channel# (VME) |
1 | 16 | 17 | 1 |
2 | 14 | 19 | 3 |
3 | 12 | 21 | 5 |
4 | 10 | 23 | 7 |
5 | 8 | 25 | 9 |
6 | 6 | 27 | 11 |
7 | 4 | 29 | 13(no cable) |
For Plastika
Plastika Sense Wire # | VPI PostAmplifier Output(ADC && TDC) | ADC Channel# (VME) | TDC Channel# (VME) |
1 | 15 | 18 | 2 |
2 | 13 | 20 | 4 |
3 | 11 | 22 | 6 |
4 | 9 | 24 | 8 |
5 | 7 | 26 | 10 |
6 | 5 | 28 | 12 |
7 | 3 | 30 | 14(not connected) |
Electronics
VPI postamp range
The VPI postamp has an adjustable gain on the TDC output. The peak to peak pulse amplification ranges approximately from x2 to x10. The ratio of the area under the pulse in case of minimum amplification is about 8.96 and in case of maximum it is ~ 650.
Noise
Timing
Using The Stanford Pulse Generator, Model DG535, four identical pulses were injected into the GEM(I mean output),, two PMTs and DC(first Metalica and then Plastika).
Data taking
(12/23/08)
Mini DCs and GEM detectors are sandwiched between the two PMTs. The top scintillator is operated at 1050 Volts and bottom one-1000 Volts.
HV settings on GEM detector:
HV settings on DCs: Sense=1450 Volts, Field=-725 Volts && Guard=724 Volts.
The coincidence pulse from two PMTs is used as a trigger and gate for GEM and DCs.
The PreAmp voltage on DCs is set to 6.4 Volts, the pulse form DC is amplified using PostAmplifier(amplification is on maximum). The TDC output of the amplified pulse is discriminated using the Leading Edge Discriminator and putted to the NIM-ECL converter, which than goes to the TDC(VME). The ADC output of the PostAmp was used for ADC(VME).
Run Number is r685
(1/5/08)
The GEM ADC measurements from the last cosmic run do not show a GEM signal while the DC has a clear ADC signal. Is the GEM output in time with the ADC gate?
I only saw one GEM signal from Trig out when triggering the scope on the bottom scintillator. It looked like
Some drift chamber signals start hat before the gate suggesting there is too much delay on the gate line.
I observed more DC signals from channel 7 than GEM trigger signals when I triggered the scope on the bottom scintilator. Could the GEM gain/efficiency be substantially lower than the DC?
- When running with HRRL electrons we should probably set the HV for each detector so they have the same rate.
Changed integrate gate from 150 ns to 300ns
Increased GEM HV 25 volts from 3325/2925 to 3350/2950
(1/6/09)
starting cosmic run # 686 on Jan 6 17:54.
- Next week let's do plateau measurements, change HV and measurements cosmics for 1 day to plot rate -vs- voltage
- Mac will double check his calculations for the correct sense wire HV.
Plateau measurement when S:F:G=2:-1:1
Voltage is changing only on Metalica. The HV setting for Plastika are set to the fixed values:
The Sense, Field, and Guard (S:F:G) wire HV ratios are 2:-1:1
HV settings on Sense Wire (Volts) | Run Number | Run Period (minutes) | ADC23 Signal Counts/scint trigger (bin 70:4000)" | ADC24 Signal Counts/scint trigger (bin 70:4000)" | Cosmic Coincidence Rate (Counts/min) | ADC23 Rate (Counts/min) | ADC24 Rate (Counts/min) |
1600 | r695 | 1774 | 1376/1842 = 0.747 | 1404/1842 = 0.762 | 1.028185 | 0.775648253 | 0.791431793 |
r708 | 1034.69 | 1099/1103=0.996 | 1099/1103=0.996 | 1.06602 | 1.0621538 | 1.0621538 | |
1550 | r693 | 635.3 | 557/746 = 0.747 | 562/746 = 0.753 | 1.174248 | 0.876751141 | 0.884621439 |
1500 | r691 | 1459.7 | 1201/1502 = 0.800 | 1168/1502 = 0.778 | 1.028978 | 0.822771802 | 0.800164417 |
1450 | r692 | 1007.85 | 796/1049 = 0.759 | 793/1049 = 0.756 | 1.040829 | 0.789800069 | 0.786823436 |
1400 | r696 | 2874.25 | 2124/2867 = 0.741 | 2146/2867 = 0.749 | 0.997477 | 0.738975385 | 0.746629556 |
1350 | r710 | 872.25 | 668/791=0.8445 | 653/791=0.825 | 0.9068 | 0.765835 | 0.764835483 |
The efficiency for Plastika (ADC24) seemed to track with Metalik's efficiency even though the HV on Metalika was changing while Plastica's HV stayed constant. We believe we are still in the plateau region and should make measurements with a sense wire voltage less than 1350 Volts.
- Histograms for Each ADC
(1/14/09)
Comparison of two runs: r685_vsr691
The HV for Sense wire in run 685 was set to 1450 Volts and for 691 - 1500 Volts
Plateau Measurements when S:F:G=1:-0.5:0.7
The previous efficiency measurements seems to all be still on the plateau. We need to change the Guard voltage to be 70% of the Sense wire voltage instead of 50%.
Mac's prediction is that the BABY chamber voltages need to be (sense,field,guard) = 1340,-670,940 for the BABY chamber to have a gas gain similar to the present CLAS chambers (which I think is about 1.7*10^4).
Let's set Plastika to those voltages as a control and change Metalika's voltage maintaining the S:F:G=1:-0.5:0.7. Let's try going to lower voltage first.
Plastika is set to the following voltages: (Sense,Field,Guard) = 1340,-670,940
HV settings on Sense:Field:Guard (Volts) | Run Number | Run Length (minutes) | Metalica Sense Wire 4 (ADC23) Signal Counts/scint trigger (bin 70:4000)" | Plastika Sense Wire 4 (ADC24) Signal Counts/scint trigger (bin 70:4000)" | Cosmic Coincidence Rate (Counts/min) | Metalica Sense Wire 4 Rate (Counts/min) | Plastika Sense Wire 4 Rate (Counts/min) |
1500:-750:1050 | r715 | ||||||
1300:-650:910 | r716 | 1844.37 | 1525/1907=0.799685 | 1544/1907=0.809649 | 1.033957 | 0.8268406 | 0.83714222 |
1250:-625:875 | r718 | 984.79 | 824/1031=0.79922405 | 830/1031=0.80504365 | 1.04692371 | 0.8367266 | 0.84281928 |
1200:-600:840 | r719 | 1271.3 | 1067/1331=0.8016529 | 1075/1331=0.8076634 | 1.0469598 | 0.839298 | 0.84559113 |
1150:-575:805 | r734 | 1257.3 | 845/1145=0.7379913 | 867/1145=0.75720524 | 0.91068165 | 0.672075082 | 0.68957289 |
1050:-525:735 | r735 | 462.97 | 277/378=0.7328042 | 279/378=0.738095 | 0.81646759 | 0.5983109 | 0.60263084 |
HV settings on Sense:Field:Guard (Volts) | Metalica Sense Wire 4 ADC23(bin 70:4000) | Plastika Sense Wire 4 ADC24(bin 70:4000) | Metalica Sense Wire 4 (ADC23) Gaussian fit | Plastika Sense Wire 4 (ADC24) Gaussian fit |
1500:-750:1050 | 150px | 150px | ||
1300:-650:910 | ||||
1250:-625:875 | ||||
1200:-600:840 | ||||
1150:-575:805 | ||||
1050:-525:735 |
HV settings on Sense:Field:Guard (Volts) | Run Number | Metalica Sense Wire 4 ADC Mean Value | Plastika Sense Wire 4 ADC Mean Value |
1300:-650:910 | r716 | 277 +/- 3.1 | 276.1 +/- 2.7 |
1250:-625:875 | r718 | 277.2 +/- 6.8 | 278.9 +/- 6.7 |
1200:-600:840 | r719 | 281.6 +/- 5.1 | 274.5 +/- 4.2 |
1150:-575:805 | r734 | 283.9 +/- 14.5 | 285.4 +/- 14.1 |
1050:-525:735 | r735 | 272.5 +/- 44.9 | 286 +/- 58.8 |
Plateau Measurements of Wire 4 using scaler
For these measurements, the high voltage on Plastika was fixed to (S:F:G=1400:-700:980) and the HV on Metalica was changed preserving the HV ratio (S:F:G=1:-0.5:0.7). The output from sense wire 4 was measured for these plateau measurements. The signal from the DCs(Plastika and Metalica Sense Wire 4) was sent to the UVA 122B Signal Splitter on channels 2(Metalica) and 15(Plastika), after that the output is sent to the VPI PostAmp. The Amplified pulse(amplification for Plastika and Metalica is about x10), from channel # 16 for Metalica and channel # 3 for Plastika, is discriminated using LeCroy Octal Discriminator Model 623B. The discriminator threshold was changed only for Metalica, for Plastika it was set to 300 mV, for whole run.
We would expect to see a plateau curve which looks like
We had the following observations for the Baby chambers
Does this mean we have not entered the Geiger Muller region or is noise impacting the low HV measurements?
on different scales:
HV Settings S:F:G=1400:-700:980
Discriminator Threshold On Metalica | Run Length(sec) | Metalica Sense Wire 4 # of events | M4 events/hr | P4 events/hr |
Noise + 10 mV =170 mV | 108 | 107 | 3566.7 | |
102 | 121 | 4270.6 | ||
91 | 106 | 4193.4 | ||
130 mV | 10 | 110 | ||
11 | 109 | |||
12 | 117 | 3.68e+4 | 2000||
150 mV | 879 | 1626 | ||
193 | 304 | |||
87 | 158 | 6.3e+3 | 440399 | 81|
250 mV | 338 | 316 | ||
88 | 91 | |||
178 | 171 | 3.5e+3 | 151433 | 44|
350 mV | 203 | 152 | ||
185 | 118 | |||
182 | 154 | 2.7e+3 | 306394 | 71|
450 mV | 245 | 133 | ||
733 | 405 | |||
360 | 181 | 1.9e+3 | 76470 | 89|
550 mV | 238 | 102 | ||
184 | 91 | |||
175 | 89 | 1.7e+3 | 126382 | 75|
650 mV | 409 | 108 | ||
578 | 150 | |||
313 | 95 | 9.9e+2 | 71300 | 81|
750 mV | 497 | 100 | ||
588 | 135 | |||
394 | 82 | 7.7e+2 | 43285 | 24
Discriminator Threshold On Metalica | Run Length(sec) | Metalica Sense Wire 4 # of events | M4 events/hr | P4 events/hr |
Noise + 10 mV =170 mV | 108 | 107 | 3566.7 | |
102 | 121 | 4270.6 | ||
91 | 106 | 4193.4 | ||
130 mV | 10 | 110 | ||
11 | 109 | |||
12 | 117 | 3.68e+4 | 2000||
150 mV | 879 | 1626 | ||
193 | 304 | |||
87 | 158 | 6.3e+3 | 440399 | 81|
250 mV | 338 | 316 | ||
88 | 91 | |||
178 | 171 | 3.5e+3 | 151433 | 44|
350 mV | 203 | 152 | ||
185 | 118 | |||
182 | 154 | 2.7e+3 | 306394 | 71|
450 mV | 245 | 133 | ||
733 | 405 | |||
360 | 181 | 1.9e+3 | 76470 | 89|
550 mV | 238 | 102 | ||
184 | 91 | |||
175 | 89 | 1.7e+3 | 126382 | 75|
650 mV | 409 | 108 | ||
578 | 150 | |||
313 | 95 | 9.9e+2 | 71300 | 81|
750 mV | 497 | 100 | ||
588 | 135 | |||
394 | 82 | 7.7e+2 | 43285 | 24
HV Settings S:F:G=1300:-650:910
Discriminator Threshold On Metalica | Run Length(sec) | Metalica Sense Wire 4 # of events | M4 events/hr | P4 events/hr |
Noise + 10 mV = 180 mV | 4351 | 233 | 192.8 | 608 |
2611 | 155 | 213.7 | 360 | |
1671 | 109 | 234.8 | 213 | |
150 mV | 51 | 162 | ||
45 | 108 | |||
466 | 1034 | 9.4e+3 | 1495291 | 153|
200 mV | 9422 | 1566 | ||
7396 | 1477 | 658 | 60286 | 6|
250 mV | 3375 | 112 | ||
2745 | 66 | |||
4315 | 123 | 103 | 13396 | 14|
300 mV | 19605 | 242 | ||
22791 | 294 | 45 | 1379 | 11|
350 mV | 8812 | 84 | ||
13023 | 115 | |||
13706 | 112 | 32 | 2393 | 12|
450 mV | 50365 | 263 | 19 | 330 |
550 mV | 8868 | 12 | 5 | 545 |
650 mV | 43949 | 48 | 6620 |
HV Settings S:F:G=1200:-600:840
Discriminator Threshold On Metalica | Run Length(sec) | Metalica Sense Wire 4 # of events | M4 events/hr | P4 events/hr |
Noise + 10 mv = 180 mV | 25492 | 206 | 3170 | |
120 mV | 58 | 129 | ||
121 | 247 | 7.7e+3 | 329||
130 mV | 1422 | 166 | ||
1645 | 62 | 278 | 142||
150 mV | 16426 | 138 | ||
23339 | 227 | 33 | 2||
200 mV | 15686 | 122 | 28 | |
300 mV | 58303 | 137 | 12373 | |
400 mV | 79553 | 42 |
HV Settings S:F:G=1100:-550:770
Discriminator Threshold On Metalica | Run Length(sec) | Metalica Sense Wire 4 # of events | M4 events/hr | P4 events/hr |
Noise + 10 mv = 70 mV | 2006 | 46 | 82.6 | 1368 |
7245 | 139 | 69.1 | 4901 | |
7245 | 96 | 47.7 | 2536 | |
120 mV | 551 | 237 | ||
589 | 280 | 1630 | 81||
130 mV | 1019 | 45 | ||
1429 | 48 | 140 | 19||
140 mV | 10719 | 108 | 36 | |
150 mV | 91588 | 981 | 39 | 245 |
200 mV | 69663 | 375 | ||
129673 | 705 | 20 | 1292 | 12|
300 mV | 47273 | 41 | 6112 | |
400 mV | 46857 | 37 | 4034 |
HV Settings S:F:G=1000:-500:700
Discriminator Threshold On Metalica | Run Length(sec) | Metalica Sense Wire 4 # of events | M4 events/hr | P4 events/hr |
Noise + 10 mv = | ||||
150 mV | 33285 | 240 | 26 | 440 |
200 mV | 52659 | 441 | 30 | 365 |
250 mV | 8390 | 48 | 21 | 962 |
350 mV | 147583 | 198 | 95232 | |
450 mV | 73359 | 15 | 59700 |
HV Settings S:F:G=700:-350:490
Discriminator Threshold On Metalica | Run Length(sec) | Metalica Sense Wire 4 # of events | M4 events/hr | P4 events/hr |
Noise + 10 mv =80 mV(can be 70) | 3995 | 2 | 3787 | |
4359 | 5 | 3946 | ||
581 | 0 | 516 | ||
200 mV | 15201 | 98 | 23 | 614 |
300 mV | 48725 | 235 | 17 | 580 |
400 mV | 3850 | 4 | 4 | 635 |
5373 | 4 | 3 | 1639 | 4|
300 mV(3/03/2009) | 51701 | 14 | 43904 | |
200 mV (4/03/2009) | 44469 | 153 | 38953 |
HV Settings S:F:G=500:-250:350
Discriminator Threshold On Metalica | Run Length(sec) | Metalica Sense Wire 4 # of events | M4 events/hr | P4 events/hr |
Noise + 10 mv = | ||||
140 mV | 3809 | 48 | 45 | 651 |
200 mV | 11713 | 33 | 10 | 680 |
250 mV | 56322 | 181 | 11 | 727 |
300 mV | 4225 | 0 | 0 | 694 |
Plateau measurement when VPI gain = x10 and Disc thresh = 80 mV
The above plateau measurements were done using the UVA splitter. In addition to cross talk, the splitter also increased the noise level. About 70 mV out of 140 mV of noise is due to the splitter. If the DC output goes directly into the VPI post amp the noise level goes down to about 70 mV. A grounding strap to the DC preamp power supply will decrease this noise to below 40 mV.
HV settings on Metalica are following S:F:G = 1300:-650:910
HV Settings S:F:G | Run Length(sec) (ch # 01) | Plastika Sense Wire 4 # of events(ch # 09) | P4 events/hr | M4 (ch # 15) events/hr | ratio X |
1400:-700:980 | 95 | 289 | 100 | 2890 | |
30 | 92 | 31 | 2967 | ||
34 | 99 | 10825 | 24532 | 3096 | |
1300:-650:910 | 110 | 100 | 108 | 925 | |
140 | 109 | 170 | 641 | ||
145 | 102 | 2869 | 306139 | 774 | |
1200:-600:840 | 929 | 121 | 972 | 124 | |
722 | 114 | 819 | 139 | ||
950 | 102 | 475 | 74967 | 106 | |
1100:-550:770 | 2142 | 29 | 49 | 0.22252 | 13 |
700:-350:490 | 73329 | 1572 | 77 | 0.0274782 | 21 |
500:-250:350 | 217503 | 4231 | 70 | 0.02467034 | 9 |
I am confident that below 1200 Volts there is just noise, If there is a pulse the rate cant be approximately 7 events/hr.
Scint coinc Plateau measurement using 1 DC
Now that we may have our cross talk problems gone and the noise reduced lets try to measure the plateaus again using 2 scintillators in coincidence .
Connector Tables
For Metalica
Metalica Sense Wire # | VPI PostAmplifier Output(ADC && TDC) | ADC Channel# (VME) | TDC Channel# (VME) |
1 | 8 | 12 | 14 |
2 | 7 | 8 | |
3 | 6 | 9 | |
4 | 5 | 1 | 10 |
5 | 4 | 12 | |
6 | 3 | 11(not used) | |
7 | 1 | 13 |
For Plastika
Plastika Sense Wire # | VPI PostAmplifier Output(ADC && TDC) | ADC Channel# (VME) ???? | TDC Channel# (VME) |
1 | 16 | 18 | 1 |
2 | 15 | 20 | 2 |
3 | 14 | 22 | 3 |
4 | 13 | 24 | 4 |
5 | 12 | 26 | 5 |
6 | 11 | 28 | 7(not used) |
7 | 10 | 30 | 6 |
24-04-2009
The HV settings on Metalica and Plastika are following: S:F:G=1350:-675:945. Metalica is placed between two scintillators. As a trigger and gate the coincidence pulse from PMTs is used. Only sense wire # 1 and # 4 of metalica are connected to the ADC and TDC of VME crator.
Experimental Setup for tracking tests
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Mini-prototype