WG: [ RadSafe ] Mistake on the UMRC web site

[Rainer.Facius at dlr.de]

Dear Keith,

thank you for pointing out this typo.

Regarding your other remarks, I interpreted the alpha decay energies given in

http://atom.kaeri.re.kr/ton/index.html

as their kinetic energies. With the corrected alpha energy for U-238 the table would be as below.

Of course, the main - or rather sole - reason for my comment was to point out the problems in using absorbed dose for high-LET particles at low fluences as a measure of exposure. This remains unaltered by my error.

Thank you once more and best regards, Rainer

A    |     B     |      J       |   C    |       D       |   E
238  |   4.270   |  6.84129E-13 |  24.43 |   8.60385E-12 | 0.07951
235  |   4.679   |  7.49658E-13 |  27.97 |   1.29122E-11 | 0.05806
234  |   4.859   |  7.78498E-13 |  29.61 |   1.53193E-11 | 0.05082
with the column headers:
A: U-isotope; B: alpha energy/ MeV; J: alpha energy / J;
C: range/micro-m tissue equivalent plastic A-150
D: irradiated spherical mass / kg; E: dose in Gy per decay



________________________________

Von: Bradshaw, Keith [mailto:keith.bradshaw at niras.co.uk]
Gesendet: Mo 13.03.2006 17:18
An: Facius, Rainer
Betreff: RE: [ RadSafe ] Mistake on the UMRC web site



Dear Rainer, I think there is a typo in column B, the alpha energy of U-238
is wrong?  

In fact the others appear wrong also, but to a lesser degree. Have you used
the Q value or the main alpha energy?  Or have I got this hopelessly mixed
up?

Keith Bradshaw
Laboratory Technical Manager
NIRAS Analytical Services
The Renaissance Centre
601 Faraday St
Birchwood Park
WARRINGTON
WA3 6GN
UK

Tel: 01925 675643 or 01925 675366
Fax: 01925 850830

web:  www.niras.co.uk


-----Original Message-----
From: Rainer.Facius at dlr.de [mailto:Rainer.Facius at dlr.de]
Sent: 13 March 2006 12:03
To: rhelbig at california.com; radsafe at radlab.nl
Cc: theveteran2 at yahoogroups.com
Subject: AW: [ RadSafe ] Mistake on the UMRC web site
<CUT>

A    |    B      |      J       |   C    |       D       |   E
238  |   6.47915 |  1.03807E-12 |  46.25 |   5.83791E-11 | 0.01778
235  |   4.679   |  7.49658E-13 |  27.97 |   1.29122E-11 | 0.05806
234  |   4.859   |  7.78498E-13 |  29.61 |   1.53193E-11 | 0.05082
with the column headers:
A: U-isotope; B: alpha energy/ MeV; J: alpha energy / J;
C: range/micro-m tissue equivalent plastic A-150
D: irradiated spherical mass / kg; E: dose in Gy per decay

With the claimed numbers of decays per year (which are in the same ball park
where my numbers for a plain uranium pellet of the specified size lie)
substantial doses will be absorbed by those cells which actually were
affected by the radiation.

<CUT>