Abdehait at 00:28, 8 June 2013

2013-06-08T00:28:07Z

Abdehait: /* THGEM#9 counting experiment */

2013-06-08T00:27:46Z

THGEM#9 counting experiment

Abdehait: /* THGEM#9 counting experiment */

2013-06-08T00:27:09Z

THGEM#9 counting experiment

Abdehait: Created page with "=THGEM#9 counting experiment= The same setup above for THGEM#9 is used for a counting experiment. The aim is to compare the number of counts in an hour for three different case…"

2013-06-08T00:25:44Z

Created page with "=THGEM#9 counting experiment= The same setup above for THGEM#9 is used for a counting experiment. The aim is to compare the number of counts in an hour for three different case…"

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=THGEM#9 counting experiment=

The same setup above for THGEM#9 is used for a counting experiment.

The aim is to compare the number of counts in an hour for three different cases:

case 1-The alpha source's shutter is closed.

case 2- The alpha source's shutter is closed and a gamma source (Co-60) placed on the detector's entrance window.

case 3-The alpha source's shutter is open the gamma source is removed

case 4-The alpha source's shutter is open and a gamma source (Co-60) is placed on the detector's entrance window.

{| border="1" cellpadding="4"
|-
|V_cathode || THGEM_1T || THGEM_1B || <math>\Delta V1 </math>|| THGEM_2T || THGEM_2B || <math>\Delta V2 </math>|| THGEM_3T || THGEM_3B || <math>\Delta V3 </math>
|-
| 4200 || 2950 || 2450 || 500|| 1950 || 1200 || 750 || 950 || 100 || 850
|}

;Experimental Setup

Trigout-> 474 ortec timing filter amp. -> EGG&G ESN CF4000-01 discriminator (5 mV threshold) -> tennelec TC534 counter and timer.

{| border="1" cellpadding="4"
|-
| case # ||case 1 || case 2 || case 3
|-
| counts/hr || 462 || 2400 || 2759
|}

According to the number of counts in each case:

1- The detector detects cosmic rays (noise). (assuming the shutter stops all the alpha particles without any ionization)

2- The detector is sensitive to gamma rays (2400-462 = 1938)

3- The detector is sensitive to alpha particles (2759-462 = 2297) considering the same assumption above.

= Discriminator level-count level relationship =

{| border="1" cellpadding="4"
|-
|V_cathode || THGEM_1T || THGEM_1B || <math>\Delta V1 </math>|| THGEM_2T || THGEM_2B || <math>\Delta V2 </math>|| THGEM_3T || THGEM_3B || <math>\Delta V3 </math>
|-
| 4359 || 2950 || 2450 || 500|| 1950 || 1200 || 750 || 985 || 100 || 850
|}

The following table represent the discriminator level and the count rate that is measured in 10 minute time interval with the shutter '''OPEN''' and 474 ortec timing filter amp. amplification is '''x6'''.

{| border="1" cellpadding="4"
|-
| discriminator level
! colspan="6" | Counts/min
|-
| (mv) || Trial 1 || trial 2 || Trial 3 || Trial 4 || trial 5 || Ave <math>\pm</math> err
|-
| 5 || 80.7 || 104.2 || 67.4 || 64.5 || 72.8
|-
| 7 || 96.6
|-
|8 ||
|-
|9 || 36.8
|-
|10 ||
|-
|12 || 11.2
|-
|13 ||
|-
| 15 || 5.1
|-
|18 || 3.7
|-
|20 || 3.2
|-
|50 ||0
|-
| 75 || 0.1
|-
| 100||0
|}

=Counting Experiment using Leading Edge discriminator (Lecroy 623b)=

The same setup above for THGEM#9 is used for a counting experiment.

The aim is to compare the number of counts for three different cases:

case 1-The alpha source's shutter is closed.

case 2- The alpha source's shutter is closed and a gamma source (Co-60) placed on the detector's entrance window.

case 3-The alpha source's shutter is open the gamma source is removed

case 4-The alpha source's shutter is open and a gamma source (Co-60) is placed on the detector's entrance window.

{| border="1" cellpadding="4"
|-
|V_cathode || THGEM_1T || THGEM_1B || <math>\Delta V1 </math>|| THGEM_2T || THGEM_2B || <math>\Delta V2 </math>|| THGEM_3T || THGEM_3B || <math>\Delta V3 </math>
|-
| 4200 || 2950 || 2450 || 500|| 1950 || 1200 || 750 || 950 || 100 || 850
|}

The amplifier amplification affect the count rate, the follwing table shows the effect as the discrimination level is 1.19V :

{| border="1" cellpadding="4"
|-
| Amplification || Count rate (Count/min)
|-
| x10 || 1.37x10^7
|-
| X6 || 1151
|-
| x4 || 9
|-
| x2 ||1
|-
| x1 || 1
|}

based on the above table, the amplification is chosen to be '''x6''' for the measurement below.

{| border="1" cellpadding="4"
|-
| case # || case 1 || case 2 || case 3 || case 4 || Notes
|-
| counts/min || 1.55 x 10^7 || || || || disc. level = 0.30V (700 mV sq.p-p)
|-
| counts/min || 2.08 x10^6 || || || || disc. level = 0.53 mV (1.8V sq.p-p)
|-
| counts/min || 6902 || || || || disc. level = 1.1 V (3V sq.p-p)
|-
| counts/min || 3222 || || || || disc. level = 1.2 V
|-
| counts/min || 1469 || || || || disc. level = 1.3 V
|-
| counts/min || 680 || || || || disc. level = 1.4 V
|-
| counts/min || 113 || || || || disc. level = 1.5 V
|-
| counts/min || 64 || 84 || || || disc. level = 1.62 V (4V sq.p-p)
|-
| counts/min || 10 || 11 || || || disc. level = 1.7 V
|-
| counts/min || || || || || disc. level = 1.8 V
|-
| counts/min || 10 || 9 || || || disc. level = 1.9 V
|-
| counts/min || 7 || 9 || || || disc. level = 2 V
|}

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	\| counts/min \|\| 7 \|\| 9 \|\| \|\| \|\| disc. level = 2 V		\| counts/min \|\| 7 \|\| 9 \|\| \|\| \|\| disc. level = 2 V
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		+	Go Back [https://wiki.iac.isu.edu/index.php/Neutron_TGEM_Detector_Abdel#THGEM.239_Counting_Experiment__test_1.2F4.2F13]

← Older revision		Revision as of 00:27, 8 June 2013
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	3- The detector is sensitive to alpha particles (2759-462 = 2297) considering the same assumption above.		3- The detector is sensitive to alpha particles (2759-462 = 2297) considering the same assumption above.
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−	~~Go Back [https://wiki.iac.isu.edu/index.php/Neutron_TGEM_Detector_Abdel#THGEM.239_Counting_Experiment__test_1.2F4.2F13]~~

	= Discriminator level-count level relationship =		= Discriminator level-count level relationship =

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 -  The detector is sensitive to alpha particles (2759-462 = 2297) considering the same assumption above.
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 = Discriminator level-count level relationship =

THGEM - Revision history

Abdehait at 00:28, 8 June 2013

Abdehait: /* THGEM#9 counting experiment */

Abdehait: /* THGEM#9 counting experiment */

Abdehait: Created page with "=THGEM#9 counting experiment= The same setup above for THGEM#9 is used for a counting experiment. The aim is to compare the number of counts in an hour for three different case…"