Nuclear reactions induced by 12C and 16O on 205Tl and 209Bi; 214Fr isomeric ratio; compound nucleus and 8Be transfer process

1972 ◽  
Vol 192 (2) ◽  
pp. 405-416 ◽  
Author(s):  
Y. Le Beyec ◽  
M. Lefort ◽  
M. Sarda
Keyword(s):  
Compound Nucleus ◽  
Transfer Process ◽  
Nuclear Reactions ◽  
Isomeric Ratio

EVIDENCE FOR LOW-MOMENTUM-TRANSFER PROCESS IN K41 (α,n)Sc44m,g REACTIONS FROM RANGE MEASUREMENTS OF PRODUCTS

1961 ◽  
Vol 39 (3) ◽  
pp. 697-705 ◽  
Author(s):  
Taku Matsuo ◽  
T. T. Sugihara
Keyword(s):  
Momentum Transfer ◽  
Compound Nucleus ◽  
Transfer Process ◽  
Ground State ◽  
Energy Region ◽  
Thick Target ◽  
Alpha Particles ◽  
Direct Reaction ◽  
Range Distribution ◽  
Lower Limits

Average forward ranges have been measured for the product nuclides Sc43, Sc44m, and Sc44g as produced in the reactions K41(α,xn) with alpha particles in the energy region 23 to 39 Mev. These ranges, which are determined by a thick target – thick catcher technique, indicate that the (α,n)-produced isomers are formed in part by a low-momentum-transfer process above 30 Mev, its contribution being larger for the ground-state nuclide Sc44g. From a thick target –thin catcher experiment at 40 Mev, it is found that the range distribution for Sc43 is that expected for a compound-nucleus reaction. Normalizing the Sc44m and Sc44g activity distributions to that of Sc43 for the catchers farthest from the target, we estimate the lower limits for the contribution of a direct-reaction low-momentum-transfer process to the formation of Sc44m and Sc44g at 40 Mev to be about 30% and 46% respectively.

Channel effect in isomeric ratio of 137m,gCe produced in different nuclear reactions

2017 ◽  
Vol 314 (3) ◽  
pp. 1777-1784 ◽  
Author(s):  
Tran Duc Thiep ◽  
Truong Thi An ◽  
Phan Viet Cuong ◽  
Bui Minh Hue ◽  
Nguyen The Vinh ◽  
...  
Keyword(s):  
Nuclear Reactions ◽  
Isomeric Ratio ◽  
Channel Effect

New Theories of Nuclear Reactions

2018 ◽  
Author(s):  
Roger H. Stuewer
Keyword(s):  
Compound Nucleus ◽  
Nuclear Reactions ◽  
High Energy ◽  
Ernest Rutherford ◽  
Eugene Wigner ◽  
The World ◽  
Experimental Physicist ◽  
Theoretical Physicist ◽  
Michael Faraday ◽  
Gregory Breit

Bohr, inspired by Fermi’s discovery of slow neutrons, conceived his theory of the compound nucleus by the end of 1935. He went on to speculate that if the energy of a neutron incident on a nucleus were increased to the fantastically high energy of 1000 million electron volts, the compound nucleus would explode. Using small wooden models Otto Robert Frisch had constructed, Bohr lectured widely on his theory on a trip around the world in the first half of 1937. By then, Russian-born theoretical physicist Gregory Breit and Hungarian-born theoretical physicist Eugene Wigner in Princeton had conceived their fundamentally equivalent theory of neutron+nucleus resonances. Together, their theory and Bohr’s transformed the theory of nuclear reactions. Orso Mario Corbino, Fermi’s mentor, friend, and protector, died on January 23, 1937, at age sixty. Ernest Rutherford, the greatest experimental physicist since Michael Faraday, died on October 19, 1937, at age sixty-six.

scholarly journals The dispersion formula for nuclear reactions

1938 ◽  
Vol 166 (925) ◽  
pp. 277-295 ◽  
Keyword(s):  
Nuclear Reaction ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Energy Levels ◽  
Virtual State ◽  
Metastable States ◽  
Atomic Systems ◽  
Dispersion Formula ◽  
Unstable Compound

Bohr has shown that in a collision between two nuclei of which at least one is heavy, an unstable compound nucleus will be temporarily formed and that the lifetime of such a compound nucleus, measured on a nuclear scale, is usually very large. For this reason these compound nuclei have fairly well-defined energy levels ("virtual“ or "resonance" levels), and the posi­tions of these levels and the properties of the metastable states belonging to them determine the cross-sections for all nuclear reactions. Breit and Wigner (1936) gave a formula for the probability of a nuclear reaction in terms of the virtual state, taking into account only one such state, while Bethe and Placzek (1937) and Bethe (1937) generalized the formula to take account of all possible virtual states. Their formula is usually referred to as the "dispersion formula" owing to its analogy with the formula for the dispersion of light by atomic systems.

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