e. běták institute of ph ysics sas, bratislava, slovakia

Final RCM on Therapeutic Radionuclides, IAEA, May/June 20061

Production cross sections for (nreactions on 88Sr, 102Pd, 124Xe, 130Te, 152Sm, 165Ho and 191Ir leading

to therapeutic isotopes

E. Běták

Institute of Physics SAS, Bratislava, Slovakia

IAEA Research Contract No. 12425


Gamma emission in pre-equilibrium reactions:

Single-particle radiative mechanism (Běták & Dobeš, Akkermans & Gruppelaar)

Probability of emission (E1 transitions)

Spin variables (Obložinský & Chadwick)

),(/),(),()(2,

2 EnEmmbnnm

GDR

2,0 n


Computer codes with pre-equilibrium emission and released to public

PEQGM (1983) (spin-independent version, obsolete already)GNASH (1992, 1995) (also spin variables and discrete levels) (recent versions strongly improved and enlarged, but not available anymore)PEQAG (1989) (update of PEQGM)PEGAS (1993) (also spin variables) & DEGAS (plus discrete levels)

“Do-all” nuclear reactions codes with pre-eq. EMPIRE-II version 2.18 Mondovi (2002) version 2.19 Lodi (2005)TALYS (2005)


Results calculated and prepared as ENDF files. (One file received from Choi). But:


Unsolved EMPIRE problems: What is the origin of the differences between TALYS

and EMPIRE, if they are so similar?

GCASC does not work (spectra with GCASC=1 are identical to those =0)

DEGAS not used for gammas. Why (and how to correct it?)

Why the nonphysical sharp decrease above 18 MeV?


CONCLUSIONS

Pre-eq. emission useful to describe cross sections and spectra, if one is not just in double-magic region. Therein, DSD (or CDSD) model is more reliable. Physically both describe the same situation with emphasis on different aspects of the reality.

Two released “do-all” nuclear codes TALYS and EMPIRE give similar results away of closed shells. In their vicinity, there is no clear preference of either of the codes which might be universally valid.


Related publications: Běták et al.: Neutron radiative capture (pre-equilibrium

approach). NEMEA (2003) Proceedings, p. 41 Běták et al.: Activation cross sections for reactions

induced by 14 MeV neutrons on natural tin … Radiochim. Acta 93 (2005), 311

Běták et al.: Possibilities of production of diagnostic isotope 111In using neutron- and proton-induced reactions … NEMEA-2 (2004) Proceedings, p. 69

Běták: Model calculations of radiative capture … CGS-12 (2005) Proceedings, p. 226

Běták et al.: New generator method of pure 111In production in the proton-induced … (submitted, 2006)


Thank you


Sr-88 Koehler (2000) 5320 points up to 350 keV

isolated points in the Koehler’s region

Hughes (1950) 1 point at 1 MeV (2.1 mb)

Pd-102 no usable data point

Xe-124 no usable data point

Te-130 many points up to 10 keV

about 40 points 10 keV to 20 MeV (60 mb to 0.6 mb)

about 25 points 10 keV to 6 MeV (20 b to 2 b (!))

Sm-152 two sets (plus isolated points) 3 keV to 3 MeV (1.5 b to 50 mb)

one set (4 points) 25 keV to 1 MeV (600 b to 120 b (!))

Ho-165 several sets of data up to 20 MeV (10 b to 0.7 mb)

one set (5 points) 20 keV to 1 MeV (1500 b to 100 b (!))

Ir-191 several sets up to 20 (25) MeV

(EXFOR v. 1.62 – June 2004)

e. běták institute of ph ysics sas, bratislava, slovakia

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