Doing the calibration of the TAC using known delays allowed for a visible appearance that the minimum measured amplitude increased with each successive delay from 0ns to 2ns, showing that when taking an average, the delay time will allow for a relatively accurate measurement with the distribution due to scattering of light in the tube, and the time walk because of the differing peak voltage transmitted to the anode depending on the time walk and discriminator level in the TAC.
SJK 12:44, 4 October 2008 (EDT)
Calculating the travel time of light relative to initial LED position inside tube.
TAC Amplitudes for Different distances relative to Photocathode (Volts)
Trial #
Δd = 0.00m
Δd = 0.25m
Δd = 0.50m
Δd = 0.75m
Δd = 1.00m
1
.860
1.06
1.32
1.60
1.48
2
1.18
1.02
1.30
1.32
1.64
3
.940
1.12
1.00
1.02
1.60
4
1.08
1.60
1.68
1.52
1.28
5
.940
.780
1.32
1.12
1.52
6
1.04
1.34
1.22
1.30
1.92
7
.840
1.28
1.40
1.60
1.32
8
.820
1.14
1.56
1.48
1.46
9
.900
.920
1.44
1.56
1.24
10
1.10
1.08
1.40
1.30
2.06
11
1.36
1.42
1.48
1.36
1.28
12
.880
1.28
1.10
1.48
1.56
13
1.28
1.06
1.10
1.22
1.74
14
.920
1.32
1.60
1.50
1.38
15
.840
1.58
1.34
1.58
1.64
16
1.36
1.08
1.46
1.56
1.82
17
.760
.840
1.26
1.38
1.38
18
1.00
.860
1.40
1.66
1.34
19
1.22
1.14
1.50
1.62
1.58
20
1.24
1.34
1.22
.980
1.38
Avg:
1.028
1.163
1.355
1.408
1.529
All values calculated with measure function in Oscilloscope with margin of error +/- .02V