Difference between revisions of "June, 7, 2007 Cf rate measurements using Photonics PMT"
| Line 1: | Line 1: | ||
| − | Cf source was placed X cm away from face of PHotonics PMT. The PMT output signal was descriminated by a Lecroy Model | + | 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 = | = Configuration Definitions = | ||
| − | 1: Placed the Cf source | + | 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: Inserted a 2.5 cm thick steel shielding wall between Scintillator and Cf source. Right up against Scintillator |
| − | 3: Replaced steel wall with | + | 3: Replaced steel wall with 5 cm thick lead shielding brick |
| − | 4: Replaced lead brick with | + | 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 | + | 5: Increased thickness of paraffin block to 13.4 cm |
| + | 6: No source backround | ||
{| border="5" | {| border="5" | ||
! Configuration || Rate (counts/min) || Error in Rate (Counts/min) | ! Configuration || Rate (counts/min) || Error in Rate (Counts/min) | ||
|- | |- | ||
| − | | 1 || | + | | 1 || 2695 || 0 |
|- | |- | ||
| − | | 2 || | + | | 2 || 2176 || 0 |
|- | |- | ||
| − | | 3 || | + | | 3 || 855 || 0 |
|- | |- | ||
| − | | 4 || | + | | 4 || 2168 || 0 |
|- | |- | ||
| − | | 5 || | + | | 5 || 1762 || 0 |
|} | |} | ||
Revision as of 00:39, 8 June 2007
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 |