Radiochemical studies related to the development of new production routes of some diagnostic and therapeutic radionuclides

Spahn, Ingo

Radiochemical studies related to the development of new production routes of some diagnostic and therapeutic radionuclides

Authors: Ingo Spahn
Publication date: 1 January 2006
Publisher: Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag

Abstract

Nuclear reaction cross section measurements were done in connection with the development of new production routes of the therapeutic and diagnostic radionuclides

^{32}P, ^{71}As, ^{72}As, ^{73}As, ^{74}As, ^{82}Sr, ^{90}Y, ^{153}Sm and ^{169}

Yb. Investigations on the production of n.c.a.

^{73}

Se using novel targetry were also performed. Integral cross sections were measured for the

^{nat}

S(n,p)

^{32}

P,

^{nat}

Zr(n,p)

^{90}

Y and

^{nat}

Eu(n,p)

^{153}

Sm reactions using a 14 MeV d(Be) neutron field. The neutron spectrum was characterised using multiple foil activation and the code SULSA. Existing cross section data were validated within 10 - 15 %, thereby substantiating earlier evaluated and recommended excitation functions of the investigated reactions. It is inferred that for production of radionuclides via the (n,p) reaction, a fast neutron spectral source (e.g. spallation or fusion) would be better suited than a fission reactor. Proton and a-particle induced reactions were investigated in the high-mass area for the production of

^{153}

Sm and

^{169}

Yb via alternative routes. Measurements were done for the first time on the

^{nat}

Nd(

\alpha

,n)

^{153}

Sm process over the energy range of 10 to 26.5 MeV and the possible production yield of

^{153}

Sm amounts to 2 GBq. The excitation function of the

^{169}

Tm(p,n)

^{169}

Yb reaction was determined over the energy range from threshold to 45 MeV and compared with the results of nuclear model calculation based on the ALICE-IPPE code. A good agreement was found. The calculated possible production yields are lower than those via the conventional (n,

\gamma

) production route, but the produced

^{153}

Sm and

^{169}

Yb are in no-carrier-added form. Cross sections were also measured with regard to the production of

^{71}As, ^{72}As, ^{73}As and ^{74}

As via the

^{nat}

Ge(p,xn) processes and the results were compared with those from the ALICE-IPPE calculations. Possible yields were calculated together with potential impurities. The various processes contributing to the formation of

^{71}

As in the irradiation of

^{nat}

Ge were analysed by performing some additional measurements on enriched

^{72}

Ge. For the standardisation and validation of data for the production of

^{82}

Sr via the

^{nat}

Rb(p,xn) process, cross section measurements on the formation of the long-lived impurity

^{85}

Sr were done over the energy range of 25 to 45 MeV, a range where a gap still existed. Integral yields were calculated, allowing for an evaluation of the best production conditions of

^{82}

Sr. Preliminary studies on the production of n.c.a.

^{73}

Se via the

^{75}

As(p,xn) reaction using AIAs as a novel target material were also carried out. Thick target yields were determined and first tests on the radiochemical separation of n.c.a. radioselenium from the target were performed