[ RadSafe ] TLD Sensitivity

[Cary Renquist]

It seems that discrepancies in reported dose could
largely be due to how the x-ray beam hit the badge...

If the beam doesn't pass through the badge-filtration
(e.g. it hits the badge edge-on), then it will look
like the badge got exposed to high-E gammas and thus
may look like a higher dose.

Cary

> 
> -----Original Message-----
> From: radsafe-bounces at radlab.nl
> [mailto:radsafe-bounces at radlab.nl] On
> Behalf Of Sandy Perle
> Sent: Wednesday, 26 April, 2006 16:19
> To: Marvin M. Turkanis; radsafe at radlab.nl
> Subject: Re: [ RadSafe ] TLD Sensitivity
> 
> On 25 Apr 2006 at 17:04, Marvin M. Turkanis wrote:
> 
> > Is there a basis for a difference in sensitivity
> of whole body and
> wrist TLDs to X-rays from the security systems for
> checked airline
> luggage?
> 
> Your question is confusing. Similar TLD material, be
> it Lithium 
> Fluoride (Li-100 or Li-700 for example), Lithium
> Borate, etc., is the 
> same, whether it's in a whole body or an extremity
> dosimeter. The 
> only difference is that the algorithm will be
> different, based on 
> which depth dose you're measuring; i.e., 1 cm., 0.3
> cm., or 0.007 cm. 
> The phantom used for calibration is also different.
> But the 
> sensitivity is not going to be a significant
> variable, if all else is 
> the same.
> 
> As mentioned by others, the exposure to a badge, no
> matter what type 
> of badge, is significantly higher in a checked bag
> X-ray unit as 
> compared to a carry-on bag X-ray unit. This has
> nothing to do with TL 
> material sensitivity.
> 
>  
> -------------------------------------
> Sandy Perle
> Senior Vice President, Technical Operations
> Global Dosimetry Solutions, Inc.
> 2652 McGaw Avenue
> Irvine, CA 92614