The differential cross sections for the B11(He3, p)C13 and the B11(He3, d)C12 reactions have been measured at 4.5 and 5.4 Mev. Yield curves for these reactions have also been obtained over the energy region extending from 3.00 to 5.40 Mev. The angular distributions for the deuteron groups are strongly peaked in the forward direction and indicate that the simple stripping interaction is the predominant mechanism of these reactions. The angular distributions of the proton groups are more complex and more difficult to interpret; however the yield curves change rather slowly with energy suggesting that direct interaction mechanisms may be important.
ABS>The differential cross sections for the six highest energy proton ; groups from the Beâ¹(HeÂ³,p)BÂ¹Â¹ reaction were meas- . ured as a ; function of angle at a bombarding energy of 4.5 Mev. For the five highest energy ; groups, the cross sections are largest in the forward direction and are not ; symmetric about 90 deg . For all six proton groups, yields observed at large ; angles to the incident beam direction are comparable to the forward yields. A ; strong maximum in the backward direction is observed for the third excited state ; proton group. At 4.5 Mev, the total cross sections are 11.5 millibarns for the ; ground-state proton group and 7.4 millibarns for the first excited state proton ; group. For the proton groups leaving BÂ¹Â¹ in the ground and first excited ; states, differential cross sections were measured at six angles as a function of ; bombarding energy in the range from 1.8 to 5.0 Mev. In each case, the total ; cross section for the reaction shows no resonances. The change in the angular ; distributions which may be interred from these yield curves is seen to proceed in ; a gradual number with increasing bombarding energy. Differential cross sections ; for the second and third excited state proton groups were measured at 7 and 90 ; deg in the bombarding energy interval from 3.0 to 5.0 Mev. The observed ; characteristics for this reaction taken together indicate that direct ; interactions are important. (auth);
The differential cross sections were studied as functions of angle and ; bombarding energies for the BÂ¹Â°(t,p)BÂ¹Â² reactions leading to the ; ground and 0.95-, 3.39-, and 3.75-Mev states of BÂ¹Â²; for the BÂ¹Â°; (t,d)BÂ¹Â¹ reactions leading to the ground and 2.14-Mev states of BÂ¹Â¹; ; and for the BÂ¹Â°(t, alpha )Beâ¹ reactions leading to the ground and ; 2.430- and 3.04-Mev states of Beg. The total cross sections for these reactions ; at 1.950 Mev were obtained by numerical integration of differential cross ; sections and are 6.4, 8.0, 6.8, and 5.6; 35 and 16; and 12, 24, and 10 mb, ; respectively. The differential cross sections for all groups exhibit very smooth ; energy dependences and the total cross sections appear to approach essentially ; constant values in the vicinity of Coulomb barrier. The angular distributions of ; the ground state deuteron group were fitted with plane wave calculations ; including stripping and heavy-particle stripping. The energy dependence of the ; angular distribution of the groundstate alpha -particle group suggests that the ; BÂ¹Â°(t, alpha )Beâ¹ reaction proceeds, to some extent, by a pickup ; interaction. Possible mechanisms for the other reactions are also discussed. 28 ; references. (auth);
A new beta-ray spectrogoniometer for electron-electron angular correlation measurements was designed and constructed. It consists of two sector-type double-focusing spectrometers. Design of the apparatus and data of performance are described. As an example, an electron-electron directional correlation function of the Pb206 gamma-gamma cascade obtained with this instrument is presented.
A simple and inexpensive target chamber with an exit port that can be ; moved under vacuum through angles from --5 to 140 deg is described. The movable ; seal is made by a spring steel tape sliding against a rubber gasket. A method of ; moving this tape is presented. The chamber was built for use with a broad-range ; spectrograph but would be suitable for use with other detecting devices. (auth);
Differential cross sections have been measured as functions of angle and bombarding energy in the region from 1 to 2 MeV for the following reactions: (1) N14(t, t)N14; (2) N14(t, α)C13 going to the ground state and the 3.09-MeV state in C13; (3) N14(t, d)N15 going to the ground state of N15; and (4) N14(t, p)N16 going to the ground state and the 0.120-, 0.295-, and 0.392-MeV states of N16. The total cross sections for the last three of these reactions at 2 MeV are: (2) 11 and 6 mb; (3) 48 mb; and (4) 7, 4, 9, and 8 mb, respectively. The energy and angular behavior of the differential cross sections suggest that most of these reactions proceed predominantly by direct interactions. The large absolute value of the cross section for the N14(t, do)N15 reaction, as well as the energy and angular behavior of the differential cross section, suggest that this reaction may proceed by a cluster exchange process. Distorted-wave Born approximation (DWBA) calculations provide satisfactory fits to the (t, αo) angular distribution, but not the (t, do). Plane-wave calculations including exchange stripping give more acceptable fits to the (t, do) data.
Differential cross sections for the ground-state proton group from the C/; sup 12/(t,p)CÂ¹â´ reactions, and for the groundstate and first-excited-state ; alpha groups from the CÂ¹Â²(t, alpha )BÂ¹Â¹ reactions, were studied as ; functions of the angle of emission and the bombarding energy at 0.800 to 2.025 ; Mev. Elastically scattered tritons were also studied at l.000 to 1.950 Mev. The ; angular distributions of all reaction groups are complex. The basic structure of ; the angular distributions for the ground-state alpha group is retained throughout ; the energy region studied; however, it shifts toward higher angles with ; increasing bombarding energy. The structures of the angular distributions for ; the first-excited-state alpha group and the ground-state proton group shift ; smoothly toward lower angles with increasing energy. The first-excited-state ; alpha group exhibits a resonance at l.13 Mev at which the total cross section ; increases by a factor of 4. The width of this resonance is about 50 Kev. Angular ; distributions of this group are not affected by the resonance, and the effects ; of this resonance are negligible in the other reaction channels. Total cross ; sections for all of the reaction groups increase rapidly between l.5 and l.7 Mev. ; This increase may be partially due to a broad anomaly in the region of l.8 Mev. ; The total cross sections for the ground-state and first-excited-state alpha ; groups at l.95 Mev are 330 and 30 mb, respectively. The CÂ¹Â²(t, alpha )B/; sup 11/ reactions may proceed by a direct cluster exchange interaction'' in ; which the distortion effects may play an important part. (auth) affected by the ; resonance, and the effects of this resonance 9464(already scanned);
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