Summary
The γ-ray spectrum following the radioactive decay of the95Tc isomer (half life 62d) has been investigated by scintillation techniques. The sources were obtained by Mo(d, 2n) reactions in the synchrocyclotron of the Institute for Nuclear Physics Research in Amsterdam. The measurements were performed with a NaI(Tl) welltype crystal (76 mm×76 mm) and the different spectra were displayed in a 200 channel LABEN analyser. γ-γ cascades were investigated with a conventional coincidence set-up and using the summing technique. The direct disintegration of the isomeric state of95Tc to the stable95Mo, in competition with the 39 keV isomeric transition to the95Tc ground-state, is confirmed. Excited levels of 1040, 820, 780 and 203 keV are assigned to the95Mo structure, de-exciting mostly with the following transitions, in keV: 1040 (5±1), 838 (38±4), 820 (13±2), 780 (17±2), 580 (50±5); 203 (100).
Riassunto
Si è studiato, con tecniche a scintillazione, lo spettro γ associato al decadimento radioattivo dello stato isomerico del95Tc, ottenuto per reazione (d, 2n) sul Mo naturale. Le misure si sono effettuate con un cristallo NaI(Tl) a pozzo, ottenendo anche informazioni sulle cascate γ-γ con la tecnica di somma, oltre che con circuiti a coincidenze convenzionali. Gli spettri sono stati analizzati con un selettore di impulsi LABEN a 200 canali. Si conferma il decadimento per cattura elettronica, dell’isomero95Tc a stati eccitati del95Mo cui vengono assegnati livelli a 1 040, 820, 780 e 203 keV. La diseccitazione di questi livelli avviene essenzialmente per transizioni γ le cui energie (in keV) e intensità relative sono: 1 040 (5±1), 838 (38±4), 820 (13±2), 780 (17±2), 580 (50±5), 203 (100).
Similar content being viewed by others
References
B. N. Cacciapuoti:Phys. Rev.,55, 110 (1939);J. E. Edwards andM. L. Pool:Phys. Rev.,72, 384 (1947);D. T. Eggen andM. L. Pool:Phys. Rev.,74, 57 (1948);E. E. Motta andG. E. Boyd:Phys. Rev.,74, 344 (1948).
H. Medicus, P. Preiswerk andP. Scherrer:Helv. Phys. Acta,23, 299 (1950).
G. E. Boyd andB. H. Ketelle: ORNL-1053 (1951);V. S. Shpinel:Žur. Ėksp. Teor. Fiz.,27, 387 (1954).
C. Levi, L. Papineau andN. Saunier:Compt. Rend.,245, 1918 (1957).
G. E. Boyd andB. H. Ketelle:Phys. Rev.,83, 216A (1951).
H. A. Medicus andP. Preiswerk:Phys. Rev.,80, 1101 (1950).
J. P. Unik andJ. O. Rasmussen:Phys. Rev.,115, 1687 (1959).
F. K. McGowan andP. H. Stelson:Phys. Rev.,109, 901 (1958).
E. C. Woodward:Phys. Rev.,93, 954 (1954);J. Owen andI. M. Ward:Phys. Rev.,102, 591 (1956).
J. Quidort:Compt, Rend.,246, 2119 (1958).
R. E. Holland andF. I. Lynch:Bull Am. Phys. Soc.,4, 232, (1959).
Author information
Authors and Affiliations
Additional information
Comunicato al XLVI Congresso della Società Italiana di Fisica, Napoli (Settembre-Ottobre 1960).
Rights and permissions
About this article
Cite this article
Chilosi, G., Ricci, R.A., Varcaccio, G. et al. On the decay of the95Tc isomer. Nuovo Cim 19, 1121–1130 (1961). https://doi.org/10.1007/BF02731388
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF02731388