ORTEC 473 - Nai Mode Walk Test; Fig. 7.2. Test Setup for Scintillation Mode Walk Test

17
HP 8004A
Rep Rate
1K(CW)
Pulse Width
lOnsiCCW)
Pulse Del.
O(CCW)
Amplitude
5 V
Amp. Vernier -
CW
Pulse Polarity -
Neg.
DC Offset
Off
Output
ThruSig. In \
Trigger Output
TEK.
CT 3
TIME PICK OFF
1
TE
50
ATTENU
K
ATOR
Pick Off
Stop
473
Shaping Mode - Scint
Disc. Mode - C.F.
Disc, level - O.OSOV(CCW)
457
TIME to PULSE HEIGHT
CONVERTER
Range
-
.05
CG
-
10
Multi
-
1
FG
- (Adjust)
Bias
-
(Adjust)
Gate
-
Anti
Strobe
-
Int.
Pos. Output
RG/62 -
(1 Meg) 1 p
100
'—wv—I
NOTE: Alt cables are SOU coax (RG/58) unless otherwise specified.
TEK.485
SCOPE
Ext. Trigger
Fig. 7.2. Test Setup for Scintillation Mode Walk Test.
8. Change the attenuator in the following sequence while observing the oscilloscope: X5X10, X10, XI.
Adjust R32 as necessary so that the 457 output amplitude changes no more than 400 ps (2 divisions) for the attenuator
changes in step 8.
10. Set the attenuator at X2X5X10 and observe the peak spread of the 457 output. If the spread exceeds 400 ps, adjust R32
to reduce it. Repeat steps 8 and 9. If R32 cannot be adjusted to satisfy both conditions, replace the MC10116 integrated
circuit, 101.
7.5. Nal MODE WALK TEST
1. Set up the system as shown in Fig. 7.3. Adjust the HP8004A output pulse width to 25 ns.
2. Use X2X5 on the attenuator.
3. Adjust the 457 bias so its output pulse shows about 6 V of amplitude as seen on the oscilloscope.
4. Set the vertical gain of the oscilloscope for 1 V/division.
5. Adjust the 457 bias and Fine Gain until a change of 1 ns corresponds to a IV (1 -division) change on the oscilloscope.
6. Change the oscilloscope vertical gain to 0.5V/division.