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Summary In this paper an attempt is made to show the value of programming as an educational tool. The algorithmic approach to problem solving, well‐known in an area such as Computer Science, can usefully be applied to many other fields. A course in computer programming is an ideal way to learn the algorithmic approach. It teaches the student to unravel a given problem by breaking it up into simple steps for which elementary solutions may be formed. He also learns to validate his solution. Learning to program a computer will develop the student's capability for logical reasoning. Analysing his problem by breaking it up into smaller problems will help to find solutions and also to pin‐point the areas where new ideas will have to be introduced. Hence apart from learning a technique (to use a computer), programming has the beneficial effect of providing the student with a thinking attitude which is not easily gained from any other discipline.

Recent measurements by the Birmingham group of the scattering and polarization of 29 MeV 3He particles are analysed in terms of a simplified version of the strong absorption, model. The differential elastic scattering cross section σ(θ) and the polarization P(θ) for 12C Sn and Au are fitted by means of three parameters. The values of the parameters for scattering of 3He by different nuclei are found to be consistent. An estimate of the 3He-nucleus spin-orbit interaction indicates that its magnitude is similar to that of the nucleon-nucleus spin-orbit interaction.

Title of program: COEF Catalogue number: ACRE Program obtainable from: CPC Program Library, Queen’s University of Belfast, N. Ireland (see application form in this issue) Computer: ICL 1901A, Installation: University of Port Elizabeth Operating system: ICL automatic operator Programming languages used: FORTRAN IV High speed store required: 14080 words. No. of bits in a word: 24 Is the program overlaid? No No. of magnetic tapes required: None What other peripherals are used? Card Reader; Line Printer No. of cards in combined program and test deck: 625 Card punching code: ICL 1900

Preparation and properties of new cobalt(II) complexes using ligands with OSO sets of donor atoms, viz. bis(N,N-dimethylacetamido)-thioether (TTDA) and bis(N-methyl-N-phenylacetamido)thioether (DTDA), are reported. Magnetic, spectral and non-aqueous conductivity data were obtained. Penta-coordinate structures are proposed for solid CoX2. TTDA (X = Cl−, Br−, I−, NO3 − and NCS-) and CoX2. DTDA (X = Cl−, Br− and NCS-). Similar data for Co(NO3)2. DTDA and Co(ClO4)2. 2TTDA strongly suggest distorted octahedral structures for these. Gaussian analysis on the solid reflectance spectra were done.

We present a combined analysis of the angular distributions for elastic, inelastic, quasi-elastic and quasi-inelastic scattering in the 3He + 48Ti system at 25 MeV, involving transitions between the ground and 2+ excited states in 48Ti and their isobaric analogue states in 48V. The analysis is made by means of a closed formalism based upon an extension of the Austern-Blair theory and the strong absorption model. The results strongly suggest that the quasi-inelastic scattering contains equal contributions from one-step and two-step processes.

Recently, shell model wave functions for low-lying nuclear states in the range 29Si-40Ca with intermediate coupling and configurational mixing, have been calculated. In this paper these wave functions are used to obtain numerical values for magnetic dipole moments and magnetic dipole transition rates. Expressions are given for the matrix elements of the magnetic dipole operator in terms of single-particle matrix elements. The ground state magnetic moments and the widths for M1 transitions to the ground state are calculated (i) with single-particle g values; (ii) with effective g values) for the nuclei in the range 29Si-40Ca. The results are tabulated.

In the proton energy range Ep = 2.995−4.006 MeV, 48 resonances have been observed in the reaction 30Si(p,γ)31P. Angular distributions of the ground state decay γ-rays yielded unique spins for 21 of these resonances levels in 31P. Angular correlation of the decay γ-rays through the first and second excited states of 31P have been measured for 17 resonance states yielding 15 spin assignments. The parity of a number of levels was deduced from the measured radiation widths and mixing parameters.

In the energy range Eα = 2.10−3.25 MeV, twenty-three resonances are reported from radiative alpha capture in 30Si. For the thirteen strongest resonances the main modes of decay and the resonance strengths are given. Angular distribution and angular correlation measurements yield the spin and parity of nine Jπ = 1− resonances and of three Jπ = 2+ resonances. Comparison of the radiative widths of E1 transitions in the compound nucleus 34S, as calculated from the measured resonance strengths, with those of analogous E1 transitions in 32S, indicates that in this mass-region the isobaric-spin selection rule inhibits the E1 transition speed in self-conjugate nuclei by about one order of magnitude.

Shell model calculations on nuclei in the region 28 < A "< 40 are performed with the as- sumption of an inert 2aSi core. The theory underlying these calculations has been described in an earlier paper. The numerical results are presented here. The values of the two-particle interac- .tions in the 2s~ ld t shell and the binding energies to the ~sSi core of 2s~ and ld t particles are derived from experimental level energies. The calculated energies, spins and configurations of about 400 levels are listed. With the nuclear wave functions obtained, the spectroscopic factors for stripping reactions are calculated and, where possible, compared with the experimental data. (two-particle) interactions between nucleons in the various configurations of the 2s~ 1 d~t shell can be expressed in terms of fifteen interaction energies of two-particle configurations. With the binding energies (to the 28Si core) of a nucleon in the 2s~ shell and in the ld~ shell one thus obtains seventeen parameters in terms of which the interaction matrix elements of the nuclear Hamiltonian can be expressed. Most of the necessary two-particle interactions are diagonal; however, some non-diagonal inter- actions are also needed to evaluate the mixing between states of different configura- tions, but with the same spin and isospin. The best values of the seventeen parameters are obtained from a least-squares fitting procedure, in which computed energies are compared with energies of a number of states with experimentally well-known spin and isospin. This requires linearization and iteration processes, also described in paper I. A tentative set of the parameters was obtained by a preliminary inspection of the experimental data and comparison with Arima's results 2). For the first run on the computer only the energies of ground states and a few first excited states were utilized. With the parameters obtained in this way, the energies of more states were computed and compared with experiment. Some of these states were selected and taken along in the next computer run. This process was repeated several times. Altogether fifty states were taken along in the final fitting procedure. With the values of the parameters thus obtained, the energies and wave functions

In the energy range E alpha = 2.10 to 3.25 Mev, twenty-three resonances are reported from radiative alpha capture in /sup 30/Si. For the thirteen strongest resonances, the main mode of decay and the resonance strengths are given. Angular distribution and angular correlation measurements yield the spin and parity of nine 1/sup -/ resonances and of three 2/sup +/ resonances. Comparison of the radiative widths of E1 tran sitions in the compound nucleus / sup 34/S, as calculated from the measured resonance strengths, with those of analogous E1 transitions in /sup 32/S, indicates that in this mass-region the isobaric-spin selection rule inhibits the E1 transition spee in self-conjugate nuclei by about one order of magnitude. (auth)

A variable-energy gamma-ray system is described. Monoenergetic gamma radiation undergoing Compton scattering produced this energy variability over a significant range. The pararneters of the system are described. Gamma radiation from a Co/sup 60/ source of strength 1200 C was Compton scattered from a copper scatterer. The energy of the scattered radiation varies continuously from 1.33 Mev in the forward direction to 0.21 Mev at a scattering angle of 180 deg . The rays of mean energy 480 kev, corresponding to a mean scattering angle of 69.5 deg , were reasonantly scattered by lithium. From a self-absorption experiment the mean life of the first excited state of Li/sup 7/ was found to be (1.48 plus or minus 0.35) x 10/sup -13/ sec. (auth)

The (α,p) reaction on31P in the energy rangeE α=3.25 to 5.25 MeV and the (α,n) reaction on29Si in the energy rangeE α=3 to 4.8 MeV, have been used to determine nuclear properties of35Cl and33S respectively. Resonance energies, strengths and partial widths are reported. The analysis of angular distribution measurements yields spin values for 23 resonance levels in35Cl and 14 levels in33S.

The angular distributions and total cross sections of 20 BeV protons scattered by eight target nuclides ranging from Li to U are analyzed by means of the strong absorption model of Frahn and Venter. The analysis accounts for contributions from both coherent and incoherent (quasi-elastic) scattering. Good agreement with all the data is obtained for a consistent set of parameters. The main result of this investigation is conclusive evidence for a sizable negative real part of the coherent scattering amplitude. In high-energy approximation this corresponds to a real part of the central proton-nucleus potential which is repulsive in the nuclear surface.

Differential cross sections of quasi-elastic ( 3 He, t) reactions are analyzed by means of a simple closed formula. Simultaneous fits of the angular distributions for elastic and quasi-elastic scattering prove the validity of the phase rule for transition to the ground isobaric analogue state.