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.

The VPI PostAmp is set to minimum gain

The VPI PostAmp is set to maximum gain

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: [math]V_{Drift}=3300[/math] Volts and [math]V_{GEM}=3000[/math] Volts
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: [math]V_Sense=1450[/math] V, [math]V_F=-725[/math] V and [math]V_G=725[/math] V.

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

HV settings on Sense Wire (Volts)

Run Number

ADC17_tot

ADC17_peak

ADC17_gaussian_fit

ADC18_tot

ADC18_peak

ADC18_gaussian_fit

ADC19_tot

ADC19_peak

ADC19_gaussian_fit

ADC20_tot

ADC20_peak

ADC20_gaussian_fit

ADC21_tot

ADC21_peak

ADC21_gaussian_fit

ADC22_tot

ADC22_peak

ADC22_gaussian_fit

ADC23_tot

ADC23_peak

ADC23_gaussian_fit

ADC24_tot

ADC24_peak

ADC24_gaussian_fit

ADC25_tot

ADC25_peak

ADC25_gaussian_fit

ADC26_tot

ADC26_peak

ADC26_gaussian_fit

ADC27_tot

ADC27_peak

ADC27_gaussian_fit

ADC28_tot

ADC28_peak

ADC28_gaussian_fit

ADC29_tot

ADC29_peak

ADC29_gaussian_fit

ADC30_tot

ADC30_peak

ADC30_gaussian_fit

1600

r695

1550

r693

1500

r691

1450

r692

1400

r696

1089/1477 = 0.737

(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 [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

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

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 [math]\pm[/math] 1495	291 [math]\pm[/math] 153
200 mV	9422	1566
	7396	1477	658 [math]\pm[/math] 60	286 [math]\pm[/math] 6
250 mV	3375	112
	2745	66
	4315	123	103 [math]\pm[/math] 13	396 [math]\pm[/math] 14
300 mV	19605	242
	22791	294	45 [math]\pm[/math] 1	379 [math]\pm[/math] 11
350 mV	8812	84
	13023	115
	13706	112	32 [math]\pm[/math] 2	393 [math]\pm[/math] 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 [math]\pm[/math] 329
130 mV	1422	166
	1645	62	278 [math]\pm[/math] 142
150 mV	16426	138
	23339	227	33 [math]\pm[/math] 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 [math]\pm[/math] 81
130 mV	1019	45
	1429	48	140 [math]\pm[/math] 19
140 mV	10719	108	36
150 mV	91588	981	39	245
200 mV	69663	375
	129673	705	20 [math]\pm[/math] 1	292 [math]\pm[/math] 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

350px

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 [math]\pm[/math] 1	639 [math]\pm[/math] 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 [math]10^3[/math]
1400:-700:980	95	289		100	2890
	30	92		31	2967
	34	99	10825[math] \pm[/math] 245	32	3096
1300:-650:910	110	100		108	925
	140	109		170	641
	145	102	2869 [math]\pm[/math] 306	139	774
1200:-600:840	929	121		972	124
	722	114		819	139
	950	102	475 [math]\pm[/math] 74	967	106
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.

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

[1] Go back Mini-prototype

Go Back

@@ Line 45: / Line 45: @@
 |7 || 3 || 30 || 14(not connected)
 |}
 == Electronics==
@@ Line 613: / Line 612: @@
-   I am confident that below 1200 Volts there is just noise, If there is a pulse the rate cant be approximately 70 events/hr.
+   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=
@@ Line 627: / Line 679: @@
 [http://wiki.iac.isu.edu/index.php/Mini-prototype] Go back
 [[Mini-prototype]]
+[http://wiki.iac.isu.edu/index.php/User_talk:Didbtama Go Back]

Difference between revisions of "GEM and Mini Prototype DC Cosmics Run"

Latest revision as of 05:06, 8 December 2012

Contents

Experimental Setup for efficiency tests

Connector Tables

For Metalica

For Plastika

Electronics

VPI postamp range

Noise

Timing

Data taking

(12/23/08)

(1/5/08)

(1/6/09)

Plateau measurement when S:F:G=2:-1:1

(1/14/09)

Plateau Measurements when S:F:G=1:-0.5:0.7

Plateau Measurements of Wire 4 using scaler

HV Settings S:F:G=1400:-700:980

HV Settings S:F:G=1300:-650:910

HV Settings S:F:G=1200:-600:840

HV Settings S:F:G=1100:-550:770

HV Settings S:F:G=1000:-500:700

HV Settings S:F:G=700:-350:490

HV Settings S:F:G=500:-250:350

Plateau measurement when VPI gain = x10 and Disc thresh = 80 mV

Scint coinc Plateau measurement using 1 DC

Connector Tables

For Metalica

For Plastika

24-04-2009

Experimental Setup for tracking tests

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