Summary
Absolute cross-sections and isomeric cross-section ratios were measured for the following reactions in which the69Zn and69Znm,71Zn and71Znm isomeric pairs are produced:69Ga(n, p),71Ga(n, p),72Ge(n, α) and74Ge(n, α). These experimental values are interpreted in terms of the spin dependence of the nuclear level density. Isomeric ratios were compared with calculations based on different nuclear models. Calculations with a shifted Fermi gas model require a moment of inertia smaller than the rigid body; in general a reasonable fit is obtained with independent-pairing and superconductor models.
Riassunto
Sono stati misurati sia i rapporti delle sezioni efficaci di isomeri sia le sezioni efficaci assolute per le seguenti reazioni nucleari:69Ga(n, p),71Ga(n, p),72Ge(n, α),74Ge(n, α), in cui vengono prodotti gli isomeri69Zn e69Znm,71Zn e71Znm. I risultati sono stati analizzati usando i calcoli statistici di Huizenga e Vandenbosch e confrontati con i calcoli basati sui vari modelli nucleari. In generale l’accordo tra teoria e dati sperimentali è soddisfacente. Nel modello del gas di Fermi l’accordo si ha solo con una riduzione del momento d’inerzia rispetto al valore relativo al corpo rigido.
Реэюме
Были иэмерены абсолютные поперечные сечения и отнощения иэомерических сечений для следуюших реакций, в которых рождаются иэомерические пары69Znи69Znm,71Znm и71Znm:69Ga(n,р),71Ga(n,р),72Ge(n, α) и74Ge(n, α). Эти зкспериментальные величины интерпретируются в терминах спиновой эависимости плотности ядерных уровней. Иэомерические отнощения сравнивались с вычислениями, основанными на раэличных ядерных моделях. Вычисления с помошью модели Фермигаэа требуют момента инерции меньщего, чем момент твердого тела; вообше, раэумная подгонка получается с моделями неэависимого спаривания и сверхпроводимости.
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References
J. R. Huizenga andR. Vandenbosch:Phys. Rev.,120, 1305 (1960);R. Vandenbosch andJ. R. Huizenga:Phys. Rev.,120, 1313 (1960).
V. N. Levkovskii:Žurn. Ėksp. Teor. Fiz.,31, 360 (1956);Sov. Phys. JETP,4, 291 (1957);Žurn. Ėksp. Teor. Fiz.,33, 1520 (1957);Sov. Phys. JETP,6, 1174 (1958).
Z. Kolar, P. Strohal andN. Cindro:Journ. Inorg. Nucl. Chem.,27, 2471 (1965).
R. E. Wood, W. S. Cook, J. R. Goodgame andR. W. Fink:Phys. Rev.,154, 1108 (1967).
C. E. Crouthamel:Applied γ-Ray Spectrometry (London, 1960).
C. Oldano andA. Pasquarelli:Nucl. Instr.,36, 192 (1965).
K. Way,et al.: Nuclear Data Sheets (National Academy of Sciences, National Research Council, 1963).
F. Demichelis andC. Oldano:Nuovo Cimento,51 B, 341 (1967).
B. P. Bayhurst andR. J. Prestwood:Nucleonics,17, 82 (1959).
M. Bormann:Zeits. Phys.,166, 477 (1962).
T. Ericson:Nucl. Phys.,6, 62 (1958);D. W. Lang andK. J. Le Couteur:Nucl. Phys.,14, 21 (1959).
A. Bohr, B. R. Mottelson andD. Pines:Phys. Rev.,110, 936 (1958);D. W. Lang:Nucl. Phys.,42, 353 (1963);H. K. Vonach, R. Vandenbosch andJ. R. Huizenga:Nucl. Phys.,60, 70 (1964);R. Vandenbosch, L. Haskin andJ. C. Norman:Phys. Rev.,137, B 1134 (1965).
T. D. Newton:Can. Journ. Phys.,34, 804 (1956);T. Ericson:Adv. Phys.,9, 425 (1960).
H. Feshbach, M. M. Shapiro andV. F. Weisskopf: Atomic Energy Commission Report NYO-3077 (1953) unpublished.
W. L. Hafner jr.,J. R. Huizenga andR. Vandenbosch: Argonne National Laboratory, Report ANL 6662, unpublished.
K. J. Le Couteur andD. W. Lang:Nucl. Phys.,13, 32 (1959).
P. E. Nemirovsky andYu. V. Adamchuk:Nucl. Phys.,39, 551 (1962).
J. H. Carver, G. E. Coote andT. R. Sherwood:Nucl. Phys.,37, 449 (1962).
J. H. Carver andG. A. Jones:Nucl. Phys.,19, 184 (1960).
D. G. Gardner andY. W. Yu:Nucl. Phys.,60, 49 (1964);D. L. Allen:Nucl. Phys.,24, 274 (1961);I. Dostrowsky, Z. Fraenkel andG. Friedlander:Phys. Rev.,116, 683 (1959).
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Demichelis, F., Guidetti, M., Miraldi, E. et al. Isomeric cross-section ratios for reactions producing the isomeric pairs69Zn and69Znm,71Zn and71Znm . Nuovo Cimento B (1965-1970) 58, 177–190 (1968). https://doi.org/10.1007/BF02711788
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DOI: https://doi.org/10.1007/BF02711788