Strain-gage instrumentation for ammunition testing

This paper deals with a feasibility study on the use of electrical-resistance strain gages for quality-assurance testing of ammunition. A special combination of strain gages was selected to measure the quantity ( \( \in _\theta + v \in _z \) ) on the outer surface of a test barrel. This combination of strain gages was essentially a stress gage which has several advantages over commercially available types. The combined strain signal was proportional to \(\sigma _\theta \) which was related to the internal ballistic pressure. The results of ballistic firings and hydraulic tests are reported which demonstrate the feasibility of this method for acceptance testing of ammunition.     

Proton hole states in 187, 189, 191Re investigated by the (t, α) reaction

Proton hole states in ¹⁸⁷Re, ¹⁸⁹Re and ¹⁹¹Re have been studied using the ($\text{t}\text{, α}$) reaction. Beams of 17 MeV tritons with a polarization of 0.75 were obtained from the tandem Van de Graaff accelerator at the Los Alamos Scientific Laboratory. The α-particles were detected in a Q3D magnetic spectrometer with a helical-cathode position-sensitive proportional counter. Spectra were recorded up to > 2 MeV excitation energy with a resolution (FWHM) of ≈ 20 keV. These measurements exhibit large analyzing powers for transitions to well-known states in the deformed nuclide ¹⁸⁷Re. This is of interest because the only other single-nucleon transfer results on heavy deformed nuclei (in a ($\text{d}\text{, p}$) study of tungsten isotopes) showed “disappointingly small” analyzing powers. The ($\text{t}\text{,α}$) analyzing powers were reproduced by DWBA calculations very well. Thus other levels in ¹⁸⁷Re and many states in ¹⁸⁹Re and ¹⁹¹Re could be assigned spins and parities on the basis of angular distributions for the cross sections and analyzing powers. In particular, the present results have made it possible to determine which of the three possible interpretations suggested previously for the structure of ¹⁹¹Re is correct. The results have been interpreted within the framework of the Nilsson model, with pairing and Coriolis mixing corrections included. The energy systematics of single-quasiparticle states are well reproduced by the Nilsson model if a hexadecapole deformation is included in the nuclear potential. Finally, it has been demonstrated that the ($\text{t}\text{, α}$) reaction is an extremely useful spectroscopic tool for studies of heavy deformed nuclei.     

A re-examination of stresses in a tension bar with symmetrical U-shaped grooves

Experimental Mechanics - A two-dimensional photoelastic study was made of stress-concentration factors and stress distributions in a statically loaded tension bar with symmetrical U-shaped grooves....     

Observation of a shell gap at N = 152 in the 246 Cm(t,p) 248 Cm reaction

Previous reports of two-neutron stripping reactions in the actinide nuclei have not indicated any excited 0⁺ strength below an excitation energy of 1.5 MeV. In contrast, the ²⁴⁶ Cm(t,p) ²⁴⁸Cm reaction shows a relatively strong 0⁺ state at 1.084 MeV. We believe that this result, coupled with a marked change in ground-state transition strenghts between ²⁴⁶ Cm and ²⁴⁸ Cm targets, indicates a gap in the single-particle orbitals that is larger than the pairing gap.     

A simple transducer for detecting projectiles in gun barrels

Strain gages were cemented on an adjustable hose clamp. The strain-gaged hose clamp was used as a simple transducer on gun barrels to detect projectiles during firing in order to synchronize other instrumentation, such as high-speed flash X rays and a pulsed-laser holographic camera, with a reproducibility of the order of one microsecond.     

Energy transfer among excited vibrational states of SF6

Studies of the risetime of laser induced 16μ fluorescence in SF₆ show the rapid equilibration (1.5 μsec torr) among the excited vibrational states. The subsequent decay of fluorescence consists of 2 exponentials. The faster of these is due to vibration-translation energy transfer (160μsec torr) and the slower is due to thermal cooling of translationally hot gas.