[en] The Tokamak Fusion Test Reactor (TFTR) vacuum chamber cover is sealed by 0-rings without the aid of mechanical fasteners. Under vacuum loading and component weights, the edges lifted no more than 0.005 in. (by a SAP4 computer code analysis). This report explains the model used for this investigation and, in addition, shows the maximum deflection expected at the center of the cover is less than 0.047 in. Also, no stresses are expected to exceed 13,700 psi

[en] Earlier inelastic scattering experiments at energies above the Coulomb barrier have shown that angular distributions for the ground state and strongly coupled excited states can provide an accurate determination of a number of nuclear deformation parameters. An inelastic scattering experiment of ²⁴Mg on ²⁰⁸Pb indicates that indeed this is a viable technique. 8 refs., 2 figs., 2 tabs

[en] On-line analytical instrumentation for monitoring elements such as S in coal must have short response time and should be reliable, cost effective and require limited maintenance. Requirements such as the above, make it difficult to transplant usual laboratory techniques as on-line equipment in coal-fired plants or coal-processing centers. PGNA have been found to be a useful technique for on-line multi-element analysis. (orig.)

[en] Differential cross sections are reported for elastic scattering and for exciting the 2₁⁺ (1.81 MeV), 2₂⁺ (2.94 MeV), 4₁⁺ (4.32 MeV), and the 4₂⁺ (4.90 MeV) states of ²⁶Mg from ²⁶Mg (200 MeV)+²⁰⁸Pb scattering. In addition, we have measured complete particle-γ angular correlations for the 2₁⁺→0₁⁺, 2₂⁺→2₁⁺, and 4₂⁺→2₁⁺ γ decays. Coupled-channels analysis was performed to extract E2 and E4 matrix elements. For the ground-state rotational band we find M(E2;0₁⁺↔2₁⁺)=-16.79±0.13 e fm², M(E4;0₁⁺↔4₂⁺)=+95±10 e fm⁴, and Q₂(2₁⁺)=-20.9±1.9 fm², where we have identified the 4₂⁺ (4.90 MeV) state as a member of the ground-state band rather than the 4₁⁺ (4.32 MeV) state. The 2₂⁺ (2.94 MeV) state is not well accounted for by the asymmetric-rotor model

[en] Differential cross sections for exciting the low-lying states in ²⁴Mg by heavy-ion inelastic scattering were measured with a new technique that uses a 4π γ-ray detector in coincidence with charged-particle detectors. The resulting data were subjected to a coupled-channels analysis to obtain a set of E2 and E4 matrix elements for exciting the 2₁⁺(1.37 MeV), 4₁⁺(4.12 MeV), and 2₂⁺(4.24 MeV) states of ²⁴Mg as well as the interconnecting and self-coupling matrix elements for these states. Our results disagree with electron scattering measurements for the charge shape of ²⁴Mg. The data on the 2₂⁺(4.24 MeV) state is not well accounted for by the asymmetric rotor model

[en] As part of an experimental study of the πNN system, the pion-deuteron breakup reaction π⁺rvec d→pnπ⁺ was investigated at intermediate energies. Distributions of the vector analyzing power iT₁₁ versus outgoing proton momentum P_p are presented for 36 πp angle pairs in the range of scattering angles 20 degree ≤θ_p≤51 degree, 62 degree ≤θ_π≤124 degree at 228 and 134 MeV. These include 7 previously unmeasured angle pairs at 228 MeV and 20 new pairs at 134 MeV. In all regions of overlap with previous measurements, there is excellent agreement. There is generally excellent agreement with relativistic Faddeev predictions, except in the np final-state interaction region at 228 MeV. This is in contrast to the cross-section measurements, which are not well described by the theory

[en] A kinematically complete measurement of the Coulomb dissociation of ¹¹Li into ⁹Li + 2n by a Pb target was made for ¹¹Li excitation energies up to ∼1.5 MeV. The ⁹Li velocity is greater than the average neutron velocity, indicating Coulomb acceleration of the ⁹Li by the Pb nucleus and, therefore, a prompt decay rather than a soft dipole resonance for the breakup process. The n-n momentum and angle correlations show no evidence for a dineutron in the ground state of ¹¹Li. A brief discussion of two neutron walls under construction and of the problems of neutron spectroscopy with large detectors are given. (authors). 16 refs., 8 figs

[en] Photodisintegration of ¹¹Li was accomplished by sending a beam of ¹¹Li at 28 MeV/nucleon through the equivalent photon field of a lead target. By measuring the complete kinematics of the disintegration products, ⁹Li+n+n, we constructed the correlation of the angle between the two neutrons in the rest frame of the ¹¹Li. The correlation is independent of angle. This result argues against the existence of a bound dineutron in the ground state of ¹¹Li. copyright 1996 The American Physical Society

[en] We have performed a kinematically complete measurement of the Coulomb dissociation of 28 MeV/nucleon ¹¹Li into ⁹Li and two neutrons by a Pb target. From the energies and angles of the emitted neutrons and of ⁹Li, the excitation energy E of ¹¹Li was determined on an event-by-event basis, and the Coulomb dissociation cross section as a function of excitation energy was constructed. The photonuclear cross section σ_E1(E) and the dipole strength function dB(E1)/dE were determined from the Coulomb dissociation cross section. σ_E1(E) has a peak at E=1.0 MeV and a width Γ=0.8 MeV. These parameters are consistent with the picture of a soft dipole mode. However, a significant post-breakup Coulomb acceleration of ⁹Li suggests instead a direct breakup. The complete kinematical measurement also allowed neutron and ⁹Li momentum distributions to be constructed in the rest frame of the ¹¹Li. The momentum distributions were fitted with Gaussian functions, yielding width parameters σ₉=18±4 MeV/c and σ_n=13±3 MeV/c. A more general feature of the breakup mechanism of ¹¹Li could be deduced from these measurements. It was found that the ⁹Li and neutron momentum distributions and the neutron-neutron relative momentum distribution could be reproduced if the ¹¹Li excitation energy was partitioned between the ⁹Li and the neutrons by a three-body phase space distribution. This indicates there is no directional correlation between the halo neutrons, and shows that the halo neutrons do not exist as a dineutron bound to a ⁹Li core

[en] Kinematically complete measurements for Coulomb dissociation of ¹¹Li into ⁹Li+2n were made at 28 MeV/nucleon. The n-n correlation function suggests a large source size for the two-neutron emission. The electromagnetic excitation spectrum of ¹¹Li has a peak, as anticipated in low-energy dipole resonance models, but a large post-breakup Coulomb acceleration of the ⁹Li fragment is observed, indicating a very short lifetime of the excited state and favoring direct breakup as the dissociation mechanism