June, 7, 2007 Cf rate measurements using Photonics PMT
Cf source was placed X cm away from face of PHotonics PMT. The PMT output signal was descriminated by a Lecroy Model 821 YYY descriminator set to pass any voltage below -0.5 mV. The descriminated output was then sent to a scaler Model ####.
Configuration Definitions
1: Placed the Cf source 16.5 cm from face of Scintillator. neutrons passing through scintillator would also pass through PMT
2: Inserted a 2.5 cm thick steel shielding wall between Scintillator and Cf source. Right up against Scintillator
3: Replaced steel wall with 5 cm thick lead shielding brick
4: Replaced lead brick with 6.7 cm thick paraffin block ( Paraffin N.F. , Household wax made by Parowax. 4 cackes, total net weight 16 oz (454 g))
5: Increased thickness of paraffin block to 13.4 cm
6: No source backround
Configuration | Rate (counts/min) | Error in Rate (Counts/min) |
---|---|---|
1 | 2695 | 0 |
2 | 2176 | 0 |
3 | 855 | 0 |
4 | 2168 | 0 |
5 | 1762 | 0 |