Re: BF3 neutron detectors

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

Well ......

When I got to LBL in 1974 out BF3 tubes were N. Woods, Lionel and Anton.

A lot has changed since then.

First off - I don't know what you refer to as delivery problems.

BF3 tubes aren't toasters!  They are not usually available off the shelf so 
delivery times are usually 90 days or so;  Unless you happen to be ordering 
their most popular configuration.  They seem to be even less off the shelf 
now than a few years ago.

Fortunately since is seems ALL BF3 tubes are made on order - there is no 
price or time penalty for custom - thus the number of configurations 
proliferates BUT we get exactly what we want.

My experience has been as follows:

Of course you cannot get Lionel or Anton any more.  When I needed to replace 
some of those LND was the only company that would make that size tube, 12 
inch by 2 inch active area.

At some time I needed to replace an N. Woods 1 inch by 5 inch 120 cm 
enriched BF3 tube.  The one I was replacing was an N. Woods - so that is 
were I went to get one.  I was told over the phone that they would not sell 
me a tube filled more than 60 cm.  I thought there was some confusion and 
stated that it was an N. Woods tube I was replacing.  They replied they 
understood - but would not sell a 120 cm tube.  I asked why - they said 
because!

That was the last time I called N. Woods.

I then went to LND.  I got a 150 cm tube made to specification.

So - for some time we have gotten LND tubes and the quoted delivery time has 
always been 90 days.

A couple of years ago I was shopping around and called  Reuter-Stokes.  They 
told me they didn't make BF3 and that I wanted He3 anyhow.  I hate it when 
someone tells me what I want.

We bought LND.

Recently we had a bunch of our new extended energy range Hankins modified 
Andersson Braun moderated BF3 detectors made by HPI (energy range extended 
to 3 gev!!).  I highly recommend this unit for your consideration.  Anyhow 
HPI checked with TGM and found the price to be fully 3 times the price of a 
BF3 tube from LND.  I had suggested LND anyhow (big surprise).

Well - LND had problems!  Their BF3 system somehow got contaminated and 
appearently it is a time consuming process to clean and test such a system - 
so the 90 delivery period became more like about 135 days.  This caused HPI 
to missed their promised delivery date and had the bean counters here 
hopping mad (even though the facilities they were to go into were also even 
more delayed).

Anyhow - after the initial grief all 20 units are here.  I am checking them 
all out right now and so far they look excellent!

I always prefer to have an item right as opposed to on time.  Although I 
will admit that 90 day delivery times ARE a pain - I DO understand what is 
involved.

So - I guess the long and short is that I have had some problem with any BF3 
tube vendor.  But LND has always made me exactly what I want and custom is 
essentially the same price and delivery time as "stock".  So - that is still 
my preference.

BTW - since the aluminum tubes are terrible for low level measurements we 
ALWAYS order the stainless tubes now.