[en] A method was developed for making high-purity carbon-14 films by radio-frequency cracking of carbon-14 labelled acetylene. The method requires only small volumes of acetylene and achieves isotopic purity of over 95% in the targets produced. The process has overall efficiency of about 22% with about 29% of the acetylene deposited on the target discs. A process for making acetylene from carbon-14 labelled barium carbonate by reacting the carbonate with magnesium and the resulting carbide with water was found to give better yields than the process based on reaction of the carbonate with lithium

[en] The new Chalk River Heavy Ion Facility will consist of a 13-MV MP Tandem Accelerator injecting into a K=520 (ME/q²) superconducting cyclotron. Physics research will be carried out in such fields as the study of nuclei far from β stability, heavy ion reactions, study of nuclei with very high spin, atomic physics, etc. The laboratory will supply not only targets needed for the experiments, but also the large quantity of carbon stripper foils for the cyclotron and the large polypropylene windows needed for various detectors and counters. It will supply such materials as carbon-14 and tritium targets to other laboratories on a limited basis

[en] A technique is described for evaporating a conductive coating on stretched polypropylene films. These are used as electrodes in a parallel plate avalanche counters for heavy ions. The stretching technique is briefly described. Stretched polypropylene films also have applications as windows for high-vacuum isolation, soft x-ray proportional counters, gas absorption cells, and energy-loss nuclear detectors

[en] Three methods are described for the production of large-area radiographic sources used in the investigation of documents. Tritium sources, which have a decay energy of 18 keV, are prepared by reacting titanium with tritium gas. Large sources of nickel-63, which has a decay energy of 67 keV, are fabricated by the resistance heating evaporation of ⁶³NiO. Finally, carbon-14 sources with electron energies of 156 keV are prepared by the glow-discharge cracking of acetylene gas. (orig.)

[en] The mass of the electron anti-neutrino can be determined from a precise measurement of the shape of the tritium spectrum near its end point. Several methods of producing appropriate tritium sources have been investigated including the tritiating of ultra-thin titanium films on quartz substrates. (orig.)

[en] Multilayer targets containing a central layer sufficiently thin so that all recoil nuclei can traverse it and subsequently stop in a suitable cubic environment have been prepared. Such targets are required in experiments making use of a magnetic field acting on an ion moving through a ferromagnetic material. The preparation and annealing of the ferromagnetic foils (iron and gadolinium) and the fabrication of the multilayer targets are described. (orig.)

[en] During the past year, the Chalk River target laboratory has developed several new methods for materials preparation related to nuclear research. These include the preparation of large-area tritium sources for paper document imaging and titanium and tungsten foil windows for water targets and high-temperature ion sources, respectively. The fabrication of ultra-thin titanium tritide sources suitable for a neutrino-mass experiment is being investigated. The preparation of radioactive sources by vacuum sublimation has also been carried out to test the focusing properties and to obtain the response function of the Chalk River iron-free β spectrometer, which will be used in the neutrino-mass experiment. (orig.)

[en] A technique has been developed to produce plastic scintillator phoswich detectors with large areas, thin ΔE layers with thickness uniformity better than 3%, and no 'dead' layer between the ΔE and E scintillators. A good signal separation for hydrogen isotopes and for elements with Z=1 to 11 has been demonstrated in two different tests with a ΔE layer as thin as 0.7 mm. The elemental resolution most probably extends beyond Z=11. The light-particle energy threshold of such a phoswich detector is only 7.5 MeV/u, ideal for reaction studies in the 10-40 MeV/u energy range available at the TASCC (Tandem Accelerator and SuperConducting Cyclotron) facility at Chalk River Nuclear Laboratories. (orig.)