Final RCM on Therapeutic Radionuclides, IAEA, May/June Production cross sections for (n reactions on 88 Sr, 102 Pd, 124 Xe, 130 Te, 152 Sm, 165 Ho and 191 Ir leading to therapeutic isotopes E. Běták Institute of Physics SAS, Bratislava, Slovakia IAEA Research Contract No
Final RCM on Therapeutic Radionuclides, IAEA, May/June Gamma emission in pre-equilibrium reactions: Single-particle radiative mechanism (Běták & Dobeš, Akkermans & Gruppelaar) Probability of g emission (E1 transitions) Spin variables (Obložinský & Chadwick)
Final RCM on Therapeutic Radionuclides, IAEA, May/June Computer codes with pre-equilibrium g 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. g EMPIRE-II version 2.18 Mondovi (2002) version 2.19 Lodi (2005) TALYS (2005)
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Final RCM on Therapeutic Radionuclides, IAEA, May/June Results calculated and prepared as ENDF files. (One file received from Choi). But:
Final RCM on Therapeutic Radionuclides, IAEA, May/June 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?
Final RCM on Therapeutic Radionuclides, IAEA, May/June 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.
Final RCM on Therapeutic Radionuclides, IAEA, May/June 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 111 In 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 111 In production in the proton-induced … (submitted, 2006)
Final RCM on Therapeutic Radionuclides, IAEA, May/June Thank you
Final RCM on Therapeutic Radionuclides, IAEA, May/June
Final RCM on Therapeutic Radionuclides, IAEA, May/June Sr-88Koehler (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-102no usable data point Xe-124 no usable data point Te-130many 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-152two 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-165several 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-191several sets up to 20 (25) MeV (EXFOR v – June 2004)