Testing Monazite using high resolution scintillators

This area is for discussions involving any fusion related radiation metrology issues. Neutrons are the key signature of fusion, but other radiations are of interest to the amateur fusioneer as well.
Post Reply
Sean-Wiseman
Posts: 7
Joined: Wed Nov 28, 2018 3:24 am
Real name: Sean Wiseman

Testing Monazite using high resolution scintillators

Post by Sean-Wiseman »

monazite-(Ce), (Ce, La, Nd, Th)PO4 (the most common member)
~
~
独居石-解谱small.jpg
~
~
who need LaBr?
~
viewtopic.php?f=20&t=12537
John Futter
Posts: 1848
Joined: Wed Apr 21, 2004 10:29 pm
Real name: John Futter
Contact:

Re: Testing Monazite using high resolution scintillators

Post by John Futter »

Sean
deadtime!!!!
or are you using "FAST" ADC's
Sean-Wiseman
Posts: 7
Joined: Wed Nov 28, 2018 3:24 am
Real name: Sean Wiseman

Re: Testing Monazite using high resolution scintillators

Post by Sean-Wiseman »

John Futter wrote: Tue Dec 04, 2018 4:33 am Sean
deadtime!!!!
or are you using "FAST" ADC's
~
sorry
what is your means?
I do not understand ^_^
John Futter
Posts: 1848
Joined: Wed Apr 21, 2004 10:29 pm
Real name: John Futter
Contact:

Re: Testing Monazite using high resolution scintillators

Post by John Futter »

Sean
The slewing of the spectra for the NaTl seem to be either too much dead time ie MCA not ready for next pulse or a damaged NaTl scintillator

I check sometime next week on the one i use (ortec 2"x2" Natl with a similar spectra
Sean-Wiseman
Posts: 7
Joined: Wed Nov 28, 2018 3:24 am
Real name: Sean Wiseman

Re: Testing Monazite using high resolution scintillators

Post by Sean-Wiseman »

John Futter wrote: Thu Dec 06, 2018 1:04 am Sean
The slewing of the spectra for the NaTl seem to be either too much dead time ie MCA not ready for next pulse or a damaged NaTl scintillator

I check sometime next week on the one i use (ortec 2"x2" Natl with a similar spectra
John
.
NaI's decay time ~250ns
presume dead time~250x5=1250ns
it can get 80,000 pulses every second.
80000cps is very big. so dead time is not a big problem if your MCA is fast enough.

My LaBr decay time about 20~25ns. ^_^
I also can sell it.
John Futter
Posts: 1848
Joined: Wed Apr 21, 2004 10:29 pm
Real name: John Futter
Contact:

Re: Testing Monazite using high resolution scintillators

Post by John Futter »

80,000 pulaes per sec could incurr 10% deadtime or more with NaTl which will slew spectra and seriously widen FHHW response hiding the rest of the spectra
as for FAST ADC's this is what I use
https://www.fastcomtec.com/?id=409
Sean-Wiseman
Posts: 7
Joined: Wed Nov 28, 2018 3:24 am
Real name: Sean Wiseman

Re: Testing Monazite using high resolution scintillators

Post by Sean-Wiseman »

John Futter wrote: Wed Dec 12, 2018 1:46 am 80,000 pulaes per sec could incurr 10% deadtime or more with NaTl which will slew spectra and seriously widen FHHW response hiding the rest of the spectra
as for FAST ADC's this is what I use
https://www.fastcomtec.com/?id=409
so you need LaBr.
LaBr decay time about 20~25ns.
NaI's decay time ~250ns
.
and 80000cps is very dangerous for man.
CZT will be better.
User avatar
vince_Darmancier
Posts: 42
Joined: Mon Dec 10, 2018 11:04 am
Real name: Vince Darmancier

Re: Testing Monazite using high resolution scintillators

Post by vince_Darmancier »

I have used a 3" X 3" standart NaI scintillation probe for almost 10 years with decent resolution...I dont feel the need for a LaBr
calibration with Co60,
Image
Monazite
Image
Uranium ore
Image
Ba133
Image
Sean-Wiseman
Posts: 7
Joined: Wed Nov 28, 2018 3:24 am
Real name: Sean Wiseman

Re: Testing Monazite using high resolution scintillators

Post by Sean-Wiseman »

vince_Darmancier wrote: Wed Jan 02, 2019 2:04 pm I have used a 3" X 3" standart NaI scintillation probe for almost 10 years with decent resolution...I dont feel the need for a LaBr
calibration with Co60,
Image
Monazite
Image
Uranium ore
Image
Ba133
Image

Image

LaBr have Higher resolution and P/C than NEW Saint-Gobain NaI Crystals.
Whether this is needed is a comprehensive result. ^_^
Attachments
new-nai&labr1.jpg
Post Reply

Return to “Neutrons, Radiation, and Detection (& FAQs)”