[en] This article discusses the history of Nuclear Physics at Chalk River. It began with the construction of a 150 kV Cockcroft-Walton generator in 1946, which was replaced in 1949 by a 250 kV generator. These machines were used to measure neutron cross sections of various elements. In 1952 a 3 MV Van de Graaff was installed and operated. Although it was intended for fast neutron work, the Van de Graaff was actually used for studying energy levels in the 1p and 2s1d shells via inelastic scattering, capture gamma, and stripping reactions involving protons, deuterons and helium projectiles. Five years later the van de Graaff was replaced by a Tandem Van de Graaff accelerator. First beam from a superconducting cyclotron was extracted in 1985

[en] The symbiosis of differential algebra and the Lie-algebraic formulation of optics provides a set of very powerful tools for analyzing and understanding the orbit dynamics of complex accelerators up to very high orders. In order to use these tools effectively it is usually necessary to express the Hamiltonian in the appropriate coordinate system. In this report, the relativistic Hamiltonian is derived in curvilinear (the fundamental coordinate system for ion-optics), Cartesian and polar coordinates, in forms suitable for solving problems in ion optics and accelerator physics both with and without the help of differential algebra

[en] A simplified model of the magnetic field of a cyclotron is used to analyse the orbit dynamics in a Lie-algebraic framework. The basic Lie-algebraic methods are outlined, including the powerful normal-form method in the context of a perturbation expansion. Analytic results are obtained for the motion of the central trajectory as well as the radial and vertical tunes. Normal form methods are used to investigate both non-resonant and resonant behaviour. It is demonstrated that for ν_x=1, all radial non-linearities vanish, leaving only the chromaticities and the axial aberrations. The one third integer resonance is investigated, including the iterated sextupole term to octupole order. Finally, analytic results were obtained for the decentering resonance, which although generally pathological, is universally used in compact cyclotrons as an aid to extracting the beam. (orig.)

[en] The theory of the least-squares analysis of experimental data is derived for the case where equations of constraint exist. Both the Lagrange-multiplier method and the elimination method are discussed. The covariance matrix for the parameters is derived and its properties are elucidated. Finally, the flow-of-information matrix is developed for the constrained case, and the properties of the influence and significance of the data on the parameters is derived and the differences between the constrained and unconstrained cases are discussed. (author)

[en] The fundamentals of ion optics are presented, beginning with the basic non-relativistic equations of motion, and the conditions under which the paraxial equations hold. The relativistically correct equations are then presented. The basic focussing properties of dipoles and quadrupoles are described as well as the operation of the quadrupole doublet and triplet. The matrix formulation of optics is developed and used to derive a number of basic results such as imaging relations, principal planes, dispersion and achromatism. The concepts of emittance, acceptance, brightness and phase space are introduced and illustrated by examples. A waist in phase space is defined, and its relationship to a focus is discussed. Both the 'Sigma matrix and Twiss formulations' for phase-space transformations are presented and their inter-relationship shown. Liouville's Theorem is also discussed along with conditions for its validity. Examples of the action of a lens and a drift space on the beam phase space are given to illustrate the power of these concepts and develop some familiarity with them on the part of the reader

[en] A two-dimensional analytic study has been made of the injection steering magnet No.2, which resides inside the yoke of the TASCC superconducting cyclotron. At high magnetic fields in the cyclotron, it was observed that the steering magnet had insufficient strength to properly inject the beam; saturation of the steering magnet as a result of leakage from the cyclotron yoke was hypothesized as the cause. This hypothesis has been confirmed by this study, and furthermore, the steering magnet has been re-designed to circumvent the above problems. Details of the analytic approach are given along with the results of the analysis of the original and redesigned magnets. (author). 4 refs., 3 tabs., 14 figs

[en] The relative efficiency of a cylindrical Ge(Li) detector has been measured as a function of the angle of incidence and the energy of the gamma rays (660, 898, 1369, 1836 and 2754 keV), for three source-to-detector distances (4.6, 8 and 10 cm between the source and the front face of the detector container). These data are used to calculate values of the attenuation factors, Q sub (k), for use in angular distribution analysis and to calculate the Doppler broadening arising from the finite solid angle of the detector subtended to a moving source. (author)

[en] The proposal for MARS, a Multidetector Array for Reaction Studies is presented. MARS consists of a large, high-vacuum vessel enclosing an array of 128 scintillation detectors for use in studies of heavy-ion collisions at TASCC. The instrument will be funded and owned jointly by AECL and NSERC

[en] At Chalk River, the final step in the identification of ¹²⁹I is a time-of-flight (TOF) measurement over a 2.5 m path. The start/stop signals are derived from microchannel plates that detect accelerated secondary electrons emitted from thin carbon films. This system provides a resolution of 400 ps (FWHM) for the 50 MeV iodine ions and the TOF peaks are closely Gaussian. Resolution is limited by the uniformity of the start-detector foil. Masses 128 and 130 are separated from ¹²⁹I by about 2 ns. To improve transmission and to reduce energy straggling, the start detector has been constructed so that the beam is unobstructed by grids. In addition to TOF, the total energy (E) of the ions is measured with a passivated implanted planar silicon (PIPS) detector. Although ¹²⁹I standards and Nal blanks require only TOF for unambiguous identification of ¹²⁹I, many environmental samples are characterized by a plethora of peaks where both TOF and E are essential for unambiguous identification of ¹²⁹I. (author)

[en] Postirradiation microstructure examinations of Zr-2.5Nb pressure tubes removed from service in CANDU reactors have shown clear trends in the dislocation structure and the state of the β-phase, as a function of operating temperature, neutron flux, and time. These microstructural parameters correlate well with changes in the mechanical properties. For example, the rapid increase in dislocation loop density in the early stages of irradiation corresponds with a rapid increase in tensile strength and DHC velocity, and a corresponding decrease in fracture toughness. There is also a strong negative correlation between the degree of β-phase decomposition and DHC velocity. In addition to the effects of microstructure evolution on the mechanical properties, changes in the a-type and c-component dislocation loop densities also affect irradiation deformation (creep and growth). Statistical analyses of the irradiation microstructure data have been used to derive empirical relationships between dislocation densities and β-phase structure with temperature, flux, and time. The relationships thus derived are useful in predicting where the mechanical properties are most affected by the in-reactor operating conditions. The predictions are compared with mechanical test data for samples from various axial and circumferential locations of 42 pressure tubes removed from operating CANDU reactors. The results are discussed in terms of the mechanisms controlling tensile strength, fracture, delayed-hydride-cracking, and in-reactor deformation. (author)