Amplifier effect on the signal

Ortec 474 timing filter amplifier amplifies the signal from the trigger output.The amplification will make a shift in the channel number compared to the same signal without application. To determine exactly the shift in channel number after the amplification, a choice for an input signal amplitude to charge the ADC just above noise, then amplifying the same input then recording the channel number (if possible). For example, generating a pulse of 0.1 V amplitude with an offset of 0.06 V using stanford research system pulse generator DG535 will hit channel 291 +_0.34 (run#4829), after the amplification it hits channel number 3767 +_0.78. Input pulse for the attenuator is 1.80V +_ 0.045, and the attenuator output pulse is 222 +_ 2.5 mV (factor of 8.1) when is set on 17.5 dB.

Amp + att. 04/26/13

Run Number	attenuation (dB)	Amplification	Average channel Number	Average channel Number - Noise (79)	calculated gain	Notes
4853	0	0	880	801	0	reference for the next two
4854	2	0	553	474	4.6
4855	4	0	304	225	11.0
4860	0	0	3399	3320	0
4861	14	0	98.46	19.46	44.6
4862	0	0	3514	3435	0
4863	14	0	133	54	36.1
4868	0	0	3903	3824	0
4869	14	0	114	35	40.8
4872	0	0	2974	2895	0
4846	24.5	yes	436	357	18.2
4848	18	yes	1720	1641	4.9
4849	20	yes	1213	1134	8.1
4850	14	yes	3210	3131	-0.7
4851	16	yes	2365	2286	2.1

Att. 04/27/13

unamplified input pulse passed through an attenuator, the attenuation is changed (without changing the input pulse offset of the input), the results are in the following table:

Run Number	attenuation (dB)	Average channel Number	Average channel Number - Noise (79)	calculated gain
4894	0	3653	3574	0
4897	8	1104	1025	10.8
4898	9	916	837	12.6
4899	6	1531	1452	7.8
4898	3	2380	2301	3.8

Amp 04/28/13

Amplified x4 level 4 fine gain

Run Number	attenuation (dB)	Average channel Number	Average channel Number - Noise (79)	calculated gain
4905	0	3779	3700	0
4906	3	2580	2501	3.4
4907	6	1776	1679	6.8
4908	9	1124	1045	10.9
4909	12	626	547	16.6
4910	15	287	208	25
4911	18	99	20	42.6

Amp and att. 05/04/13

Amplified x6 level 6 fine gain

With attenuator

According to the calibration curve above the charge collected by the ADC is determined in the table above.[https://wiki.iac.isu.edu/index.php/Neutron_TGEM_Detector_Abdel#Run_List3 ]

Att. 05/10/13 & 06/03/13

The table below shows the measurements of the charge of a square pulse that has an amplitude of -0.49 V (osc. 0.504+_ 0 V )with a zero offset and a width of 25.2us. The gate width is 70ns.

[math] Q = Q_0 10^{(L_v/20)} [/math]

Run Number	attenuation (dB)	Average channel Number	Pedestal subtracted Average channel Number	calculated gain
5120	0	3876.27	3797	0
5120	3	3057	2977
5123	6	1906	1827
5124	9	1339	1260
5125	12	940	861
5126	14	742	663
data2 06/03/13
5172	0	3818.94 +/- 0.06
5173	3	2685.03 +/- 0.05
5174	6	1889.48 +/- 0.05
5176	9	1322.00 +/- 0.03
5177	12	926.62 +/- 0.03
5178	15	647.03 +/- 0.02

Amp 06/03/13

Amplifier

An amplifier (x6 level 6) was added to amplify the signal before attenuation, a square pulse of an amplitude of (1st time-0.18V) and for (the second time 0.47V) (osc. 235 +_ 4 mV) with a zero offset and a width of 25.8us was used, the gate width was 70ns. After the amplification the signal amplitude is (first time 3.42+_ 0.29 V) (2nd time: gate integrate 4.21 +/-0 V).

[math] Q = Q_0 10^{(L_v/20)} [/math]

Run Number	attenuation (dB)	Average channel Number	Average channel Number - Noise (79)	charge collected (nC)	calculated attenuation	expected attenuation	V(mV)
5134	14	3952	3873	1.6552	0		647+_32
5135	15	3503	3424	1.4756	0.997		576+_27
5136	18	2474	2395	1.064	20*log(3952/2472) = 4.2	4	416+_16
5137	21	1752	1673	0.7752	6.589		235+_ 32
5138	24	1206	1127	0.5568	20*log(3873/1127) = 10.7	10	222 +_7
Data2	06/03/13 Pedestal 63
5180	14	2872.76 +/- 0.09					872
5181	15	2477.22 +/- 0.08					782
5182	18	1823.29 +/- 0.08					546
5183	21	1306.90 +/- 0.04					392
5184	24	933.94 +/- 0.03					271

Bat. 05/24/13

ADC calibration using a battery

Using a 1.5V battery connected to to 5 kohm resistor, then 25 ohm terminated ADC. The oscilloscope measures 15 mV DC voltage for the battery as it is 50 ohm terminated.

Run Number	channel Number	Channel Number - padestal	Gate width (ns)	Charge (nC)
62	851	771	500	0.015*(Gate width)/25 = 0.3
63	1263	1184	750	0.45
64	1702	1623	1000	0.6
65	1250	2072	2151	0.75
66	2500	3897	3976	1.5

Bat 05/30/13

ADC calibration using a battery

Using a 1.5V battery with a grounded positive terminal connected to to 5 kohm resistor, then 50 ohm terminated ADC. The oscilloscope measured 14.4 mV DC voltage of the battery when it is 50 ohm terminated.

Run Number	channel Number +_ error	Gate width (ns)	charge (nC)
97	865 +_ 0.04	500	=0.0144*(Gate width=500)/50=0.144
98	493+_0.03	250	0.072
101	1283 +_0.03	750	0.216
102		1000
104	2105 +_ 0.04	1250	0.36
106	3317 +_ 0.02	2000	0.576
107	overcharge	2500

Measurements Notes

1- The slope of the calibration curve as the ADC is connected to the battery with the positive terminal grounded is 178 pC.

2- The ADC manual manual mentioned 100pC gain/count, does count = channel? Also it is measures max. tolerate voltage >25 mV with +_ 2 mV as maximum voltage offset, the battery provides 14.4 mV offset, Does the ADC measure that the battery voltage or consider it more that the offset limit and measure only within the offset limit?

Today 05/31 the equipment moved to the LDS to start our measurements but I am still thinking how to improve our calibration curve measurements to get the right slope.

Bat. grounded 6/2/13

Measuring the grounded positive terminal battery output again in the LDS, V= 14.7 mV measured by the oscilloscope. (R= 5kohm, V=1.5, I= 1.5/5kohm = 0.3 mA, oscilloscope channel 2 is 46 ohm terminated, then V = 46*0.3mA = 13.8 mV). The ADC noise level in channel 5 (signal channel) is 63 (run #5162) which is 42.1 ohm terminated.

Run Number	channel Number +_ error	channel Number - Pedestal	Gate width width (ns)	charge (pC)
5161	356.14 +/- 0.01	293	178	= 14.7*(Gate width)/42.1 = 62.2
5163	712.09 [math]\pm[/math] 0.02	649	398	139.0
5164	1368.60 +_ 0.02	1305	798	278.6
5165	2662.70 +_ 0.02	2600	1592	555.9
5157	3670 +_ 0.01	3607	2216	773.8

Amp 06/04/13

Amplified x6 level 6 fine gain

stanford pulse generator is used as source for a negative pulse of width of 11.8us +/- 3, and the gate width is 32.94 ns +/- 0.02 . all the voltage measurement is recorded by using oscilloscope 46 ohm terminated. So the amplifier input current is (input signal amplitude/46)

Run Number	input signal (mV)	amplified pulse amp. (mV) +/- SD	Charge (pC)	Average channel Number	Average channel Number - Noise (63)
5205	51 +/- 1	676.702	945 +/- 8	2415.57 +/- 0.13	2352.57
5207	56 +/- 1	744.730	1040 +/- 8	2644.05+/- 0.10	2581.05
5208	60 +/- 1	809.178	1130 +/- 10	2840.40+/- 0.15	2777.40
5209	65 +/- 1	859.304	1200 +/- 8	3066.89+/- 0.18	3003.89
5210	70 +/- 1	916.591	1280 +/- 8	3293.51+/- 0.21	3230.51
5214	80 +/- 1	1045.49	1460 +/- 8	3744.33+/- 0.15	3681.33

Two Amp's 06/06/13

Amplified x6 level 6 fine gain and P.S. gain amplifier 777

stanford pulse generator is used as source for a negative pulse of width of 892 ns +/- 4, and the gate width is 32.7 ns +/- 0.6 . all the voltage measurement is recorded by using oscilloscope's CH2 which is 46 ohm terminated. So the amplifier input current is (input signal amplitude/46)

Run Number	input signal (mV)	amplified pulse amp. (V) +/- SD	Charge (pC)	Average channel Number	Average channel Number - Noise (63)
5253	21.6 +/- 0.3	0.79 +/- 0.01		1847.32 +/- 0.13
5254	23.6 +/- 0.3	0.86 +/- 0.01		2305.25 +/- 0.14
5255	25.6 +/- 0.3	0.94 +/- 0.01		2501.55 +/- 0.12
5256	27.6 +/- 0.3	1.02 +/- 0.01		2696.81 +/- 0.18
5257	29.6 +/- 0.3	1.09 +/- 0.01		2899.58 +/- 0.16
5258	37.3 +/- 0.3	1.40 +/- 0.01		3695.65 +/- 0.14

2 Amp's +Att11 06/06/13

Amplified x6 level 6 fine gain, P.S. 777 and attenuated 11 dB

Stanford pulse generator is used as source for a negative pulse of width of 892 ns +/- 4, and the gate width is 34.4 ns +/- 0.6 . all the voltage measurement is recorded by using oscilloscope CH2 which is 46 ohm terminated. So the amplifier input current is (input signal amplitude/46)

Run Number	input signal (mV)	ADC pulse (V)	Charge (pC)	Average channel Number	Average channel Number - Noise (63)
5278	0.1, 21.6 +/- 0.3	0.204 +/- 0.004		767.25 +/- 0.05
5281	0.15, 32.6 +/- 0.6	0.336 +/- 0.008		950.58 +/- 0.05
5282	0.20, 42.4 +/- 0.6	0.440 +/- 0.004		1235.08 +/- 0.06
5283	0.25, 52.0 +/- 0.6	0.544 +/- 0.004		1521.28 +/- 0.05
5286	0.5, 103 +/- 1	1.12 +/- 0.02		3133.79 +/- 0.08

2 Amp's +Att17 06/09/13

Amplified x6 level 6 fine gain, P.S. 777 and attenuated 17 dB

Stanford pulse generator is used as source for a negative pulse of width of 892 ns +/- 4, and the gate width is 73.4 ns +/- 0.6 . all the voltage measurement is recorded by using oscilloscope CH2 which is 46 ohm terminated. So the amplifier input current is (input signal amplitude/46)

Run Number	input signal (mV)	ADC pulse (V)	Charge (pC)	Average channel Number	Average channel Number - Noise (63)
5294	0.1, 21 +/- 1	0.204 +/- 0.004		747.63 +/- 0.07
5295	0.15, 32 +/- 1	0.336 +/- 0.008		948.89 +/- 0.05
5296	0.20, 41 +/- 1	0.440 +/- 0.004		1237.31 +/- 0.05
5297	0.25, 51 +/- 1	0.544 +/- 0.004		1539.09 +/- 0.05
5298	0.5, 102 +/- 1	1.12 +/- 0.02		3184.43 +/- 0.06

2 Amp's +Att15 06/09/13

Amplified x6 level 6 fine gain, P.S. 777 and attenuated 15 dB