05/11/2011: Difference between revisions
Jump to navigation
Jump to search
No edit summary |
No edit summary |
||
| (2 intermediate revisions by the same user not shown) | |||
| Line 10: | Line 10: | ||
So it looks like my previous threshold value (-500 | So it looks like my previous threshold value (-500 mV) was not good. Let's set it up the -200 mV. And let's see does the n's detector sensitive to the source. The same set up and distances as before. | ||
{| border="1" cellspacing="0" style="text-align: center; width: 800px; height: 100px;" | {| border="1" cellspacing="0" style="text-align: center; width: 800px; height: 100px;" | ||
! scope="col" width="50" | | ! scope="col" width="50" | | ||
| Line 17: | Line 17: | ||
|- | |- | ||
!n's | !n's | ||
|19.89<math>\pm</math>0.26 (5966 cnts) || 58.84<math>\pm</math>0.29 (17652 cnts) | |19.89<math>\pm</math>0.26 (total 5966 cnts) || 58.84<math>\pm</math>0.29 (total 17652 cnts) | ||
|} | |} | ||
So now we see the source. The ratio are: | So now we see the source. The ratio are: | ||
<math>\frac{Rate_{source}}{Rate_{w/source}} = \frac{58.84}{19.89} = 2.96<math> | <math>\frac{Rate_{source}}{Rate_{w/source}} = \frac{58.84}{19.89} = 2.96 </math> | ||
Latest revision as of 04:59, 12 May 2011
Because is something wrong I decided to measure the counts rate as function of threshold energy. Maybe my threshold was incorrect.
Below are my results for n's detector with HAMAMATSU PMT (-1500 V):
So it looks like my previous threshold value (-500 mV) was not good. Let's set it up the -200 mV. And let's see does the n's detector sensitive to the source. The same set up and distances as before.
| counts/sec (5 min test), no source | counts/sec (5 min test), with source on the top of PS1 | |
|---|---|---|
| n's | 19.89[math]\displaystyle{ \pm }[/math]0.26 (total 5966 cnts) | 58.84[math]\displaystyle{ \pm }[/math]0.29 (total 17652 cnts) |
So now we see the source. The ratio are:
[math]\displaystyle{ \frac{Rate_{source}}{Rate_{w/source}} = \frac{58.84}{19.89} = 2.96 }[/math]