Re: 131-Iodine

From: Alfredo Ferrari <alfredo.ferrari_at_cern.ch>
Date: Wed, 23 Sep 2009 17:02:10 +0200

Hi

the emission spectra used by FLUKA for 131-I are reported below. At a
first glance I don't see anything strange, but I let you check with the
relevant databases if there is something suspicious (normally our
data are adapted from the Brookhaven database). I have a suspicion (maybe
just a suspicion) about a possible misunderstading, could you please send
me the input and explain how you scored the energy?

                   Ciao!
                  Alfredo

   A: 131 Sym.: I Z: 53 m: 0 T 1/2 6.947E+05 (s)

  Decay ch. # BR into A Sym. Z m T 1/2 (s)
    B- 1 0.9891 -> 131 Xe 54 0 1.000E+38
    B-m 2 0.0109 -> 131 Xe 54 1 1.028E+06

    15 CE lines recorded:
    Energy: 0.003 MeV, BR: 7.230 %
    Energy: 0.025 MeV, BR: 0.830 %
    Energy: 0.046 MeV, BR: 4.250 %
    Energy: 0.075 MeV, BR: 0.564 %
    Energy: 0.079 MeV, BR: 0.115 %
    Energy: 0.129 MeV, BR: 0.818 %
    Energy: 0.143 MeV, BR: 0.062 %
    Energy: 0.158 MeV, BR: 0.382 %
    Energy: 0.163 MeV, BR: 0.088 %
    Energy: 0.250 MeV, BR: 0.306 %
    Energy: 0.279 MeV, BR: 0.054 %
    Energy: 0.330 MeV, BR: 1.910 %
    Energy: 0.359 MeV, BR: 0.299 %
    Energy: 0.363 MeV, BR: 0.062 %
    Energy: 0.602 MeV, BR: 0.035 %

    18 gamma lines recorded:
    Energy: 0.004 MeV, BR: 0.780 %
    Energy: 0.029 MeV, BR: 1.880 %
    Energy: 0.030 MeV, BR: 3.450 %
    Energy: 0.034 MeV, BR: 0.323 %
    Energy: 0.034 MeV, BR: 0.624 %
    Energy: 0.034 MeV, BR: 0.189 %
    Energy: 0.080 MeV, BR: 2.620 %
    Energy: 0.177 MeV, BR: 0.269 %
    Energy: 0.272 MeV, BR: 0.058 %
    Energy: 0.284 MeV, BR: 6.120 %
    Energy: 0.318 MeV, BR: 0.077 %
    Energy: 0.326 MeV, BR: 0.273 %
    Energy: 0.364 MeV, BR: 81.500 %
    Energy: 0.405 MeV, BR: 0.055 %
    Energy: 0.503 MeV, BR: 0.359 %
    Energy: 0.637 MeV, BR: 7.160 %
    Energy: 0.643 MeV, BR: 0.217 %
    Energy: 0.723 MeV, BR: 1.770 %

     6 beta+/beta- emissions recorded:
    B- end point (<E>): 0.248 ( 0.069) MeV, BR: 2.080 %
    B- end point (<E>): 0.304 ( 0.087) MeV, BR: 0.645 %
    B- end point (<E>): 0.334 ( 0.097) MeV, BR: 7.230 %
    B- end point (<E>): 0.606 ( 0.192) MeV, BR: 89.600 %
    B- end point (<E>): 0.630 ( 0.200) MeV, BR: 0.050 %
    B- end point (<E>): 0.807 ( 0.283) MeV, BR: 0.390 %

+----------------------------------------------------------------------+
| Alfredo Ferrari || Tel.: +41.22.76.76119 |
| CERN-EN/STI || Fax.: +41.22.76.69474 |
| 1211 Geneva 23 || e-mail: Alfredo.Ferrari_at_cern.ch |
| Switzerland || |
+----------------------------------------------------------------------+

On Wed, 23 Sep 2009, Ernesto Amato wrote:

> Dear all,
> thanks to the support received in this mailing-list, we succeeded in
> calculating the average energy deposition per disintegration for some
> radionuclides, uniformly distributed in cubic voxels of soft tissue.
>
> The results for Yttrium-90 and Phosporus-32 are in very good agreement
> with our results obtained with other MC codes, and with published data.
>
> We find a rough disagreement for Iodine-131 isotope, obtaining results
> approximately double with respect to the expected ones.
> In fact, we obtain <Edep> = 335 keV instead of about 178 keV for
> 6mm-side voxel, and 315 instead of about 161 keV for 3 mm voxel.
>
> Is it possible that some mistake is contained in the 131-I emission
> spectrum?
>
> Best regards,
>
> Ernesto Amato
>
>
> --
> Dr. Ernesto Amato, PhD
> EP - Physicist
> University of Messina - Italy
> Department of Radiological Sciences
> Nuclear Medicine Unit
> email: ernesto.amato_at_unime.it
> tel: +39 090 221 2942/3789
> fax: +39 090 221 2843
>
Received on Wed Sep 23 2009 - 17:53:00 CEST

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