Fusion Message Board

In this space, visitors are invited to post any comments, questions, or skeptical observations about Philo T. Farnsworth's contributions to the field of Nuclear Fusion research.

Subject: Re: Scintillator Crystals
Date: Nov 09, 9:02 am
Poster: Richard Hull

On Nov 09, 9:02 am, Richard Hull wrote:

>Does anyone know of a surplus source of NaI scintillator crystals besides OE Technologies? I have just acquired a pair of beautiful 3" PMTs that would work very well for scintillator applications. The new price for a 3" NaI crystal from Bicron is about $600, which makes the Scots half of me writhe with anguish....
> Richard Hester


Try Ebay.........search on "scintillation" and you will often snag a few scintillation counters for cheap. I have! I will give you a money back if any of them work!!! Nothing ever works out-of-box off E-bay.

However, the PMT's and Thallium activated NaI crystals are always good. I picked up a nice Harshaw 3" unit with pre-amp, meter head etc., for $28.00 a few months back. After ditching the entire electronics group, meter and case, I had a perfect preamp, PMT and mated crystal. They work fantastic!

Frankly, I have not noted a lot of difference between the NaI and BC-100 plastic scintillators.
Don at OE Tech has a yard full of the BC-100 or its equivalent for cheap. I buy his junk unpolished disks and polish one side only with Novus plastic polish. They do demand a bi-alakali PMT though. (blue sensitive)

Hanging on for just what you want is a wait and see game and requires a bit of savy to alter what you bought that doesn't work as originally built.

I haunt hamfests up and down the East coast like Capser the friendly ghost. Last weekend I found a guy with a huge open area of many instruments scattered all over the ground from a closed gov't lab. They were $5.00 each, your choice. I picked up a sulphur chemiluminesence analyzer, A UV absorption spectrometer, and two electrometers for a total of $20.00! I poured over them last night.

One electrometer needs some work, the other is perfect. The UV spectrometer yielded a 3" square diffraction grating, a short wave UV deuterium lamp (with spare lamp in head) and power supply.

The sulphur luminescent unit appears functional!!! It contained a 2kv PMT supply, PMT, preamp, 15 swagelock 1/8" fittings and three swagelock "tee" connectors, a theromcouple vacuum tube with electronics, plus a 0-5 psi regulator guage and 0-3 liter/hour flow gauge.

I called our local swagelock dealer, (who has taken a lot of my money in the past), and just one SS "tee" is $26.60.

I think it was $20.00 well spent. I took 4 hours last night and will take another 4-6 inorder to pillage the lot and disgard the shells.

I go to 13 hamfest each year, travel about three hours to the farthest and might strike gold like this at 2 of them, all the rest, I just wind up with only good deals.

There are low priced things everywhere provided one can see-at-sight and haunt the right events.

I know you will find something at a Scotsman's price.

Richard Hull