Akira Isoya

A 160 cm Synchro- and Variable Energy Ordinary Cyclotron

A 160 cm cyclotron have been constructed as the first accelerator of the Institute for Nuclear Study, University of Tokyo. This cyclotron can be used as a variable energy ordinary cyclotron as well as a synchro-cyclotron by changing the dee-system and the oscillator system. As an ordinary cyclotron it can produce protons of any desired energy between 7.5 and 15 MeV, deuterons between 15 and 21 MeV, and α particles between 30 and 42 Mev. These beams are now being used for various experiments on nuclear reactions and for production of radioisotopes. As a synchro-cyclotron, it can produce protons of 57 MeV in energy and the beam is extracted with high efficiency at a radius near n =1 with an electrostatic deflector.

The angular distributions of the long-range alpha-particles from the reaction F19(p, α0)O16

The angular distributions of the long-range alpha particles from the reaction F/sup 19/+p, leading to the ground state of the residual nucleus O/sup 16/, have been measured. The energies of protons covered a range from 630 to 1460 kev, and measurements were made in steps of 5 to 10 kev with a proton energy spread of 0.2 per cent. Coefficients in the Legendre polynomial expansion of the anguular distribution function were traced in this range. (auth)

A Detailed Study of Low-Lying Levels of 184W by Means of the (d,p) Reaction

Targets of separated isotopes 182 W and 183 W were bombarded with a 15 MeV deuteron beam, and outgoing protons were analyzed with a broad range magnetic spectrograph and nuclear emulsion plates. Empirical single-particle cross sections were determined from the observed cross sections and angular distributions of the reactions leading to low-lying levels of 183 W. Observed cross sections and angular distributions for the levels of 184 W were compared with the cross sections which were obtained by using the above empirical single-particle cross sections and the spectroscopic factors calculated from the pairing theory. For the members of the ground state rotational band and the γ-vibrational band in 184 W excellent agreements were obtained. Reasonably good agreements were found for six higher levels below 1800 keV, if they were interpreted as the rotational members of possible two-quasiparticle states. For the first two levels of the lowest excited K =0 + band cross sections were determined.

The Reactions Li7(p, n)Be7, B11(p, n)C11 and Al27(p, n)Si27 at 8 to 14 MeV

The ( p , n ) reactions for lithium, boron and aluminium targets were studied by using two kinds of proton-recoil, fast-neutron spectrometers. One is an addition type originated by Calvert, Jaffe and Maslin, the other is a type with hydrogen gas radiator. The angular distributions of Li 7 ( p , n )Be 7 neutrons corresponding to the ground and the 0.43 MeV excited states doubles at 8.1 to 14.1 MeV of proton energies and corresponding to the 4.65 MeV excited state of Be 7 at 14.1 MeV of proton energy were obtained. Using the activation method, the excitation curve of this reaction was observed with 15 MeV proton beam. The angular distributions of neutrons from the reaction B 11 ( p , n )C 11 (the ground state) at 8.1 to 14.1 MeV and from the reactions Al 27 ( p , n )Si 27 (the ground and the excited states) at 14.1 MeV of proton energy were also observed. The theory of Austern, Butler and McManus does not agree with the obtained results in the case of the reaction B 11 ( p , n )C 11 , but agrees with that i...The (p,n) reactions for lithium, boron, and aluminum targets were studied using proton-recoil, fast-neutron spectrometers. The angular distributions of Li/sup 7/(p,n)Be/sup 7/ neutrons corresponding to the ground and the 0.43 Mev excited states at 8.1 to 14.1 Mev and corresponding to the 4.65 Mev excited state of Be/sup 7/ at 14.1 Mev were obtained. Using the activation method, the excitation curve of this reaction was observed with a 15 Mev proton beam. The angular distributions of neutrons from the reaction the reactions Al/ sup 27/(p,n)Si/sup 27/ (the ground and the excited states) at 14.1 Mev were also observed. The theory of Austern, Butler, and McManus does not agree with the obtained results in the case of the reaction B/sup 11/(p,n)C/sup 11/ but agrees with that in the reaction Al/sup 27/(p,n)Si/sup 27/. It was observed that, for the reaction B/sup 11/(p,n)C/sup 11/, the isotropic parts of the angular distributions of neutrons became larger as the incident proton energies decreased and, in the cases of the reactions of Li/sup 7/(p,n)Be/sup 7/ and B/sup 11/(p, n)C/sup 1 the angular distributions of neutrons showed large variations for the different proton energies. (auth)The ( p , n ) reactions for lithium, boron and aluminium targets were studied by using two kinds of proton-recoil, fast-neutron spectrometers. One is an addition type originated by Calvert, Jaffe and Maslin, the other is a type with hydrogen gas radiator. The angular distributions of Li 7 ( p , n )Be 7 neutrons corresponding to the ground and the 0.43 MeV excited states doubles at 8.1 to 14.1 MeV of proton energies and corresponding to the 4.65 MeV excited state of Be 7 at 14.1 MeV of proton energy were obtained. Using the activation method, the excitation curve of this reaction was observed with 15 MeV proton beam. The angular distributions of neutrons from the reaction B 11 ( p , n )C 11 (the ground state) at 8.1 to 14.1 MeV and from the reactions Al 27 ( p , n )Si 27 (the ground and the excited states) at 14.1 MeV of proton energy were also observed. The theory of Austern, Butler and McManus does not agree with the obtained results in the case of the reaction B 11 ( p , n )C 11 , but agrees with that i...

THE REACTIONS Li

The ( p , n ) reactions for lithium, boron and aluminium targets were studied by using two kinds of proton-recoil, fast-neutron spectrometers. One is an addition type originated by Calvert, Jaffe and Maslin, the other is a type with hydrogen gas radiator. The angular distributions of Li 7 ( p , n )Be 7 neutrons corresponding to the ground and the 0.43 MeV excited states doubles at 8.1 to 14.1 MeV of proton energies and corresponding to the 4.65 MeV excited state of Be 7 at 14.1 MeV of proton energy were obtained. Using the activation method, the excitation curve of this reaction was observed with 15 MeV proton beam. The angular distributions of neutrons from the reaction B 11 ( p , n )C 11 (the ground state) at 8.1 to 14.1 MeV and from the reactions Al 27 ( p , n )Si 27 (the ground and the excited states) at 14.1 MeV of proton energy were also observed. The theory of Austern, Butler and McManus does not agree with the obtained results in the case of the reaction B 11 ( p , n )C 11 , but agrees with that i...The (p,n) reactions for lithium, boron, and aluminum targets were studied using proton-recoil, fast-neutron spectrometers. The angular distributions of Li/sup 7/(p,n)Be/sup 7/ neutrons corresponding to the ground and the 0.43 Mev excited states at 8.1 to 14.1 Mev and corresponding to the 4.65 Mev excited state of Be/sup 7/ at 14.1 Mev were obtained. Using the activation method, the excitation curve of this reaction was observed with a 15 Mev proton beam. The angular distributions of neutrons from the reaction the reactions Al/ sup 27/(p,n)Si/sup 27/ (the ground and the excited states) at 14.1 Mev were also observed. The theory of Austern, Butler, and McManus does not agree with the obtained results in the case of the reaction B/sup 11/(p,n)C/sup 11/ but agrees with that in the reaction Al/sup 27/(p,n)Si/sup 27/. It was observed that, for the reaction B/sup 11/(p,n)C/sup 11/, the isotropic parts of the angular distributions of neutrons became larger as the incident proton energies decreased and, in the cases of the reactions of Li/sup 7/(p,n)Be/sup 7/ and B/sup 11/(p, n)C/sup 1 the angular distributions of neutrons showed large variations for the different proton energies. (auth)The ( p , n ) reactions for lithium, boron and aluminium targets were studied by using two kinds of proton-recoil, fast-neutron spectrometers. One is an addition type originated by Calvert, Jaffe and Maslin, the other is a type with hydrogen gas radiator. The angular distributions of Li 7 ( p , n )Be 7 neutrons corresponding to the ground and the 0.43 MeV excited states doubles at 8.1 to 14.1 MeV of proton energies and corresponding to the 4.65 MeV excited state of Be 7 at 14.1 MeV of proton energy were obtained. Using the activation method, the excitation curve of this reaction was observed with 15 MeV proton beam. The angular distributions of neutrons from the reaction B 11 ( p , n )C 11 (the ground state) at 8.1 to 14.1 MeV and from the reactions Al 27 ( p , n )Si 27 (the ground and the excited states) at 14.1 MeV of proton energy were also observed. The theory of Austern, Butler and McManus does not agree with the obtained results in the case of the reaction B 11 ( p , n )C 11 , but agrees with that i...