1 - IAEA Nuclear Data Services

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The electronics designed for this experience was described in
[1][2]-
6 7
1.3. y-n reaction in the nuclei Id- Li
6 9
A Li an( i a 'Li targets were exposed to the y beam of a betatron
(30 MeV maximum energy).
The resulting neutrons were recorded using nuclear plates.
The energy spectra of the neutrons gave a measurement of the
energy of the possible excited states for nuclei Li and 'Li»
The results obtained are in good agreement with other measure­
ments previously done. The detailed results of this experiment
are given in [3] [4].
1 .4. Photodisintegration of Li m H • He.
After some preliminary experiments, nuclear plates doped with
Li° were used to study the reaction
6 Li (Y,t) 3 H.
The scanning of the emulsions is now performed.
We hope to verify in this way some predictions that come out of
6
a cluster model of the nucleus Li-.
2.1. High resolution, high efficiency y-ray spectrometer
A spectrometer for y-rays in the energy region between 20 and
100 MeV, having a 2% resolution and a mean 6% efficiency, was
assembled using two large Nal(Tl) crystals (see f5]). The
dimensions of the two crystals are 230 mm diameter x 160 mm
height, and 148 mm diameter x 93 mm height.
The smaller crystal has a central hole in which the incident
beam is collimated. The systems act as a 47T spectrometer
but with two separate crystals it is possible to impose supple­
mentary condition to improve the resolution. The spectrometer
is now completely assembled and preliminary measurements were