Re[2]: Technical Question (Thanks)

[tdc@ehssun.lbl.gov]

>The above is correct. However, if you are using a multiple element 
>TLD, the low energy x-ray should not have a problem being detected. 
>and, a response determined based on calibration data to "that" 
>spectra being assessed. If it is a single element TLD, the above 
>calibration becomes crucial, since you are now making an assumption 
>as to what the energy is, and, what calibration and correction 
>factors will be used.  In the multi-element dosimeter, the 
>approximate energy as well as the response is easily determined. 
>DOELAP and NVLAP both test down to 20 keV (NIST M30 Category), and 
>the various elemental ratios can easily pinpoint the approximate 
>energy spectra, as well as type of radiation field being detected.

True enough Sandy!  I was making my comments on the assumption that for
this kind of measurement one would prefer to use a single TLD chip - and
NOT a dosimeter that has a covering over the TLD or a multi-element
dosimeter.  A multi element dosimeter almost brings us back to the same
place this whole thread started since to use such would require some sort
of beam assessment for uniformity.

Also - for analytical x-ray units - NIST L20 is high and M30 is WAY high!
keV effective is somewhere around 5 or 6 for W anode and lower for Cu.