[ RadSafe ] Subsurface Gamma Spec Detector (drifting off topic!)

Tue Jul 19 13:00:11 CDT 2011

Joe: you are right in that a few detectors did go out, but generally, as you
mentioned, to certain companies working with NASA. And various detectors
have been all over space (including landing on certain solid bodies....)
doing valuable scientific work.

As for the good 'ol Minitron: you are right. They are a lot more robust
these days and enclosed in (fairly rugged) ceramic housings. That they are
more rugged and reliable than the early ones is attested by their use in
Logging while drilling tools, where they encounter shock levels that would
have caused instantaneous failure of the early ones and run without failure
for >500 hours drilling.....

As for glass minitrons, I well remember running early TDT logs (in the
'60s!) in Brazil. We had to run a rotary 600V converter off the old 110V
Onan to power the tool (we sent 600v downhole on the logging cable, which
powered the HV supply to the Minitron - you had to have your cable
insulation in good shape!)....... and were lucky to get 50 hours out of
them.

Cheers
Doug

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of JPreisig at aol.com
Sent: Tuesday, July 19, 2011 11:52 AM
To: radsafe at health.phys.iit.edu
Subject: Re: [ RadSafe ] Subsurface Gamma Spec Detector

Doug and Radsafe,

      Hmmmmm.  Not all EMR tubes are internal  use only.  Back in the day, I
remember the Engineers and/or Technicians used to SELECT some of the better
EMR photodetectors, and direct them to Santa Barbara (Hughes Corporation???)
California.  They used  to call them the Santa
Barbara tubes and they were always very pleased when sent one out.   
Perhaps they were used
in satellites or other industry well logging.  My Minitrons (a neutron
generator tube) cost $5K back then (1978 dollars).  My friend Jerome (an
electronics  technician) dropped one Minitron tube (that had tested well and
was ready to be shipped!!!!) on the ground and because of the glass used in
the Minitron back then, the tube broke into many pieces.  A  dumb kid
production engineer named Joe Preisig was called in to clean up the mess.
Fortunately the tritium is absorbed into the tube storage filament(s), so
the mess wasn't too bad.

      I think Minitrons have ceramic  envelopes(instead of glass) these
days.  Joanie, a QC technician commonly referred to Minitrons as
Bit__itrons.  What a cool tube to  build and work on.

     Regards,   Joseph R. (Joe) Preisig,  PhD

In a message dated 7/19/2011 12:24:57 P.M. Eastern Daylight Time,
jdaitken at sugar-land.oilfield.slb.com writes:

Joe: you  are correct that EMR (now Schlumberger's Princeton Technology
Center) makes  these detectors, but these are generally only for
Schlumberger's internal  use. And many of the integrated detectors use
commercial crystals from  Bicron/St Gobain.

They can be contacted in the States  at:
Saint-gobain Crystals
17900 Great Lakes Parkway
Hiram, OH  44234
Tel: (440) 834-5600

Regards
Doug

Doug Aitken
QHSE  Advisor, Schlumberger D&M Operations Support Cell Phone:  713-562-8585
(alternate e-mail: doug.aitken at slb.com )
Mail: c/o Therese  Wigzell,
Schlumberger,
Drilling & Measurements HQ,
300  Schlumberger Drive, MD15,
Sugar Land, Texas  77478

-----Original Message-----
From:  radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu]  On Behalf Of JPreisig at aol.com
Sent: Tuesday, July 19, 2011 11:00 AM
To:  radsafe at health.phys.iit.edu
Subject: Re: [ RadSafe ] Subsurface Gamma Spec  Detector

Hi,

_jpreisig at aol.com_  (mailto:jpreisig at aol.com) 

This is expensive  and probably a bit too much  technology for your project,
but EMR  Photoelectric/Schlumberger Technologies makes gamma detectors  for
oil  well logging.  These gamma detectors are mechanically and thermally
stable and might fit in your  geoprobe borehole.  Such a  gamma detector
used to cost  $2K (1978 dollars).
Don't know what  they go for now.

Their address is:   44  Wallace  Road, Princeton Junction, New Jersey

I expect EMR Photoelectric/Schlumberger  Technologies has a  website.  
Google it.

Such a detector  would work well with a  portable MultiChannel Analyzer and
PC.

Perhaps one could even power such a  system  in the field with a portable AC
electricity generator.

Have fun.

Joe Preisig

In a message dated 7/18/2011 10:41:32 P.M. Eastern Daylight  Time,
dgmiller at enercon.com writes:

My  internet search skills  are failing me today.  Does anyone know where to
rent or  purchase a gamma spec unit with a detector that has   dimensions
capable of logging a geoprobe boring?  I have found  the  detector in the
link below, but I don't know where to purchase  and/or   rent.

http://www.detectors.saint-gobain.com/SlimLine.aspx   

Thank you,

Dustin G.  Miller

RSO/Health   Physicist

_______________________________________________
You   are currently subscribed to the RadSafe mailing list

Before posting  a  message to RadSafe be sure to have read and understood
the RadSafe  rules.  These can be found at:  
http://health.phys.iit.edu/radsaferules.html

For  information  on how to subscribe or unsubscribe and other settings 
visit:   http://health.phys.iit.edu

_______________________________________________
You  are currently subscribed to the RadSafe mailing list

Before posting a  message to RadSafe be sure to have read and understood the
RadSafe rules.  These can be found  at:
http://health.phys.iit.edu/radsaferules.html

For information on  how to subscribe or unsubscribe and other settings
visit:
http://health.phys.iit.edu

_______________________________________________
You  are currently subscribed to the RadSafe mailing list

Before posting a  message to RadSafe be sure to have read and understood the
RadSafe rules.  These can be found at: 
http://health.phys.iit.edu/radsaferules.html

For  information on how to subscribe or unsubscribe and other settings
visit:  http://health.phys.iit.edu

_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood the
RadSafe rules. These can be found at:
http://health.phys.iit.edu/radsaferules.html

For information on how to subscribe or unsubscribe and other settings visit:
http://health.phys.iit.edu