Re: BF3 Neutron Detectors

[tdc@ehssun.lbl.gov (Ted M. de Castro)]

>>If you're going to use BF3 (vs He3) the stainless steel tubes from LND (I
>>think) seem to be among the best we've tried.  We have not had great 
>>results
>>from the N. Wood tubes.  Stainless tubes are of course more expensive.


Actually from LND the stainless is only SLIGHTLY more expensive.

We also recently ordered a He3 tube from LND and had I have had a chance to 
check it out.  The results are VERY encouraging!!  The He tube is 3.5 times 
more sensitive and just as good at gamma rejection - the BEST part is that 
it operates 225 volts lower (1225 instead od 1450!!).  I am planning on 
switching entirely to He3 as soon as I can get the $ to do so!

I was originally concerned because of conflicting information on gamma 
rejection - but it is simply no problem!

I'd also like to order one with internal an internal alpha source of around 
500 dpm.  I'd use this for constancy checks/evaluation of the electronics.