Bargain LaBr detectors

[Steven Sesselmann]

I am thinking of introducing a 38*38 mm LaBr detector in my range. LaBr crystals are the current state of the art, they have high light output and fantastic resolution and a whole bunch of other advantages, but not cheap. I recently spoke to some of the guys at ANSTO and they told me how they have just obtained several LaBr detectors for the bargain price of $25,000 each, in fact it was such a big investment they gave the detectors names.

I have been offered 38*38 mm LaBr with a 3.5% resolution guarantee at a much better price, and will be able to offer complete LaBr detectors for around US$ 7500.00, it is not likely that I will be holding these in stock, but if anyone is interested I will make them to order with selected grade PMT's.

Steven

Sample spectrum provided by my supplier

LaBr spectrum

labr.png (743.16 KiB) Viewed 2195 times

[luuk]

Hi Steve,
What is the background cts/min./cc from this crystal?
Luuk

[Steven Sesselmann]

Luuk,

According to the supplier, background due to 227Ac is less than 0.15 cps/cc

I work that out to around 12 cps for a 38*38 crystal (720 cpm)

Steven

[luuk]

Hi Steve,
That sound good but I expect that you get about 30% more background around 18 c/s.
That may look low but you need a good background subtraction if you want to use LaBr3 while measuring low activity samples.
Resolution is great if lucky you can get as low as 2.8% for 662KeV.
I have some crystals 38x38mm to test next week and shall make a background spectrum for the forum to show what to expect.
Luuk

[Steven Sesselmann]

Ac227 has a half life of 21 years, does that mean these crystals improve with age?

Maybe a good long term investment ..