Re: FW:

[mem122a@lanl.gov (Milton McLain)]

Richard,

The CR-39 alpha track detector should work.  Had you considered "ordinary"
photographic emulsions as the detector?  Need darkroom, of course, but less
complex than the chemical etching of CR-39 in many ways.  Image analysis
migiht well be applied to your problem.  You have the options of analyzing
an image from a common microscope, or performing scanning electron
microscopy (SEM) followed by image analysis of the SEM photo image/print.
If available, the use of the SEM coupled with non-dispersive X-ray analysis,
or use of an electron microprobe unit, can provide you with elemental
identification and size data, if you are lucky.   Of course, the
particle-of-interest should not be obscured or buried in the collected dust
for the best results.

Dr. James Mazzullo, Professor of Geology at Texas A&M Univ., should be a
useful source of information re applications of image analysis on such
particles.  He uses this technology extensively in measuring size and shape
parameters of individual sand grains.  His phone no. is (409)845-2441.  A
viable e-mail address may be:  mazz@tamu.edu   If this does not get to him,
let me know and I can get a valid address from the university pH database.  OK?


Milton McLain


>
>
>
>HOT DUST
>
>Personal air samplers(PAS) or static air monitors are used by workers where 
>there is the potential to inhale actinide particulates.  We are being asked 
>to develop the capabilities and establish a procedure to make retrospective 
>particle size measurements on particles collected on filter papers shown to 
>be contaminated by alpha spectroscopy.
>This is a two part problem.  We need a method of locating the active 
>particles and determine their relative activity among the non-active 
>particles, perhaps using CR39.  Once the hot particles have been located it 
>is important to know the size because the size will have a significant 
>impact on dose.   One possibility being looked into is image analysis.  This 
>is a new project for us, so any advice on this topic would be appreciated.
>
>
>Please contact Richard Richardson;
>Radiation Biology and Health Physics,
>AECL, Chalk River Research Laboratories, Chalk River, Ontario, K0J 1J0.
>
>Telephone  613-584-3311 extension 4755
>
>Fax  613-584-1713
>
>email  RICHARSON@CRL.AECL.CA
>            OR
>         RICHARDR@CRL5.CRL.AECL.CA
>
>Note:  If you reply within the next 2 weeks please forward e-mail messages 
>to Mike Wood (woodm@crl5.aecl.ca).  Mike will forward your messages to other 
>members of our internal dosimetry team.  If you would like to make contact 
>by phone please call Shelly Starling @ 613-584-8811 (4745 or 4528)
>
>
>
>