1 - IAEA Nuclear Data Services

1.3. Publications
- 120 -
Spins of Slow Neutron "Resonances in Srn, Gd, Ta, Pe and Ir Isotopes
F. Poortmans and ÏÏ. Ce ule mans, Fuel. Phys. A97, 657 (1967)
Spin Measurements of the 8.8 eV and 12.-4 eV neutrons Resonances in U
F. Poortrnans, H. Ceulemans and M. lleve de MéVergnies, Nuclear Data for
Reactors, Vol II, 211-, 1967 IAEA, Vienna 1967.
2. Fission Physios and Chemistry
2.1. Fission cross-section measurements with fission track detectors
M. NEVE de MÉVERGNIES and P. del MARMOI
2.32.
To measure the fission cross-section of Th for thermal neutrons,
a sandwich consisting of a thin Th deposit and a, plastic disk
used as a fission-track detector is irradiated in the thermal column
of the BR1 graphite reactor, inside a thick lead container so as to
minimize photo-fission reactions. The deposit has a thickness of
O.9O mg/om Th. on an Al "backing. The detector is a polyc-arbo -
nate known- as Makrofol E. The measurements are in prog]çess.
2.2. Identification of __*g and Ap in fission and nuclear charge
distribution in this mass region
P. del MARMOL
The study of A» and Ae m thermal neutron fission of y through
milking of their granddaughter products yieJLded the following results:
^As t l/2 «.(1-4.1 ± 1-1)S J cumulative yield: 81 +_ % of chain 83.
8 \g t l/2»(5.8j;0.2)s ¡ cumulative yield: 17 + 2% of chain 84.
Using ¥ahl , s method the most prohahle charge (Zp) was calculated for
"both chains and gave 32.95 ± 0.27 for mass 83 and 34-04 _+ 0.10 for
mass 84.
36 supplied hy BCMN, Euratom, Geel.