Re: <no subject>

[Steven.Rima@DOEGJPO.COM (Steven Rima)]

     Joel,
     
     There is a chart on page 160 of the old Radiological Health Handbook 
     entitled mR/mAs vs filtration at 40 inches for various kVp x rays. It goes 
     from 40 kVp to 150 kVp and from less than 1 mm up to about 4.5 mm Al 
     filtration. It won't work for all types of machines, but it is good for 
     many common applications.
     
     Steven D. Rima, CHP
     Manager, Health Physics and Industrial Hygiene
     MACTEC-ERS, LLC
     steven.rima@doegjpo.com

______________________________ Reply Separator _________________________________
Subject: <no subject>
Author:  Joel Baumbaugh <baumbaug@nosc.mil> at Internet
Date:    5/18/98 10:59 AM


        Radsafers,
     
        Hopefully someone can help me with this,
     
        I occasionally get phone calls from people (not necessarily from my
work) who have x-ray generating machines (of various/sundry natures - full-wave 
rectification/single/three phase filtered [various thickness Al plus inherent], 
etc., etc.) and they want to know if there is a way to figure out what the 
dosage rate (in air) their machines are producing at a specific distance (I also
get calls about other machines/devices generating other various/sundry products 
but we'll save that topic for another day...just x-rays today...!)
     
        Of course I would and "do" suggest measuring the darn things (with a
properly calibrated instrument, etc.) and then you'll know for sure what you're 
getting - isotopically - however I seem to remember (casting my mind "WAY back" 
that I've seen rule-of-thumb nomograms for just this sort of thing.
     
        Question(s):
     
        Do such nomograms still exist?
     
        Am I "dating" my self? - are there any "free" software packages I (or
any RADSAFER's who want to know) can download?  Can you give me a WWW address 
that I can click on?
     
        What limitations am I looking at with a "formula" for dose rates
(besides shielding of/from the machine itself - tube type [i.e. 
tungsten/copper/iron, etc.], scatter...)?
     
        Any suggestions/warnings?  Hey, why re-invent the wheel/ignore history? 
If any of you have tried this and its worthless - I want to know so I'm not 
wasting my time either...  If I find something that seems to work, then I'll do 
the calculations and then double-check it with a meter to see how close it 
is...Simple pleasures for simple minds I guess...
     
     
        Anyway, thanks (ahead of time) for your help,
     
     
     
        Joel Baumbaugh
        baumbaug@nosc.mil       
     
Joel T. Baumbaugh, MPH, MHP
baumbaug@nosc.mil
Radiation Safety Officer
SSC San Diego, CA
     
     
        NOTE:   The contents of this message have not been reviewed, nor
approved by
the Federal Government, the U.S. Navy, my bosses or my wife...
     
        How times change - how everthing remains the same:
     
2000 B.C.     "Eat this root."
1000 A.D.     "That root is heathen.  Say this prayer."
1850 A.D.     "That prayer isn't medicine.  Drink this potion." 
1940 A.D.     "That potion is snake oil.  Swallow this pill." 
1985 A.D.     "That pill is ineffective.  Take this antibiotic." 
2000 A.D.     "That anibiotic is ineffective.  Eat this root."