[en] This paper gives a detailed description of the transport of MeV protons through a nuclear microprobe lens system which is acting as an energy spectrometer. The angular distribution of transmitted protons versus their energy loss is studied for different crystal thickness and planar tilt angles using Monte Carlo simulations. The conditions under which the transmitted proton beam is deflected by the magnetic quadrupole triplet of a microprobe such that ions with slightly differing energies are focused to different locations across the image plane are discussed. The shape of the resultant beam intensity distribution and reconstructed energy spectrum is studied as a function of location along the beam axis

[en] Curved crystals are commonly used to bend and extract GeV charged particle beams from high-energy accelerators. There is growing interest in multiturn extraction schemes, whereby the circulating beam makes several passages through the curved crystal, to increase the bending efficiency and also for extending their use to TeV energies. The optimum crystal length in such schemes is typically 5 mm, which imposes difficulties both in accurately aligning and bending such short lengths. This paper examines the use of Si_1-xGe_xSi graded composition strained layers to satisfy the optimum crystal dimensions and small bend angles required in such schemes. The use of Si_1-xGe_x/Si graded layers to bend low-energy charged particles is experimentally demonstrated using 3 MeV protons. (orig.)

[en] This paper describes new imaging methods which use a nuclear microprobe lens system placed after the sample to focus the transmitted ions. Recent experimental work has demonstrated how a quadrupole lens multiplet can be used to magnify the angular distribution of unfocused proton beams passing through thin silicon crystals, and also the spatial distribution of unfocused beams of MeV protons passing through free-standing grids. It has also been shown how a highly convergent, focused MeV proton beam which passed through a thin silicon crystal could be used to directly image the defects present. Such experimental work has highlighted the need for new ion optical studies on how MeV ion beams can be manipulated by quadrupole lens multiplets in order to fully understand this previous work, and also to show how the attainable spatial and angular magnification can be further increased. This paper presents such calculations in the form of ion optical trajectory plots using the matrix ray-tracing program PRAM, which takes chromatic and spherical aberrations into account

[en] The use of a nuclear microprobe, containing a magnetic quadrupole triplet, as a high resolution energy spectrometer is proposed here. It is calculated that energy differences of ∼300 eV can be resolved for 3 MeV protons which are transmitted through thin samples, corresponding to an energy resolution of δE∼0.01%. The optics and performance of this energy spectrometer are discussed and compared with other types which are used for ion beam analysis

[en] This is a review of the use of nuclear microprobes in support of a wide variety of ''materials'' sciences. Applications areas covered include metallurgy, solid-state physics, fusion research and HT superconductors; some examples are described. The list of references concentrates on the substantial range of publications subsequent to reviews published in 1987. (orig.)

[en] Nuclear microprobes typically achieve a demagnification between 20 and 100 by using a single-stage quadrupole multiplet as the probe-forming system. Whilst quadrupole lenses provide the strong field necessary for focusing MeV ions, they also have higher intrinsic spherical and chromatic aberrations, and also higher parasitic aberrations than found in solenoid lenses. Given the fundamentally superior spatial resolution which is attainable using solenoids, their use in a two-stage microprobe system comprising a magnetic quadruplet and a solenoid lens as the first and second demagnifying stages respectively is studied here. Calculated results are compared with a two-stage system comprising two quadruplets and also with an existing single-stage system

[en] Beam rocking has been used on both the Oxford high-excitation triplet and the Melbourne Russian quadruplet to study lens aberrations such as multipole fields. A focused MeV proton beam is rocked over a fine mesh grid and the resulting beam displacement is mapped. Distorted patterns are produced in the presence of multipole fields originating either in the lenses or elsewhere due to stray fields. The minimisation of parasitic multipole fields is not only required in order to focus ion microprobes to small spot sizes, but is also important for the production of proper angular channelling scans using beam rocking since such fields distort an otherwise linear scan. In the absence of sextupole and higher order multipole fields, symmetric patterns are produced, exhibiting only spherical aberration. The patterns obtained experimentally are interpreted with the aid of simulations produced using an ion optics ray-tracing program

[en] The nuclear microprobe has been developed into an important analytical technique because of its high sensitivity and the quantitivity of particle-induced X-ray emission (PIXE), Rutherford backscattering spectrometry (RBS), and nuclear reaction analysis (NRA). Newly developed techniques such as scanning transmission ion microscopy (STIM), channeling STIM, channeling contrast microscopy (CCM), and ion-beam-induced charge (IBIC) will become important techniques because of their large depth of analysis compared to other experimental methods. The high resolution capability of the nuclear microprobe will make it an increasingly important tool in the next decade. 128 refs., 12 figs., 1 tab

[en] Monte Carlo simulations have been performed for 2 MeV protons which are planar channelled along the (1 1 0) planes of a Si crystal, in which a lattice translation was introduced at different depths to model a stacking fault. Under certain conditions of tilt angle and fault depth, the planar oscillation wavelength of the best channelled beam portion below the fault becomes greater than the wavelength above the fault, and may also be greater than that in a perfect lattice at planar alignment. The conditions under which this behaviour occurs are studied

[en] The first implementation of digital ion-beam-induced charge (IBIC) imaging is presented, which permits spectroscopic time-resolved IBIC imaging of charge transport in semiconductors. A digital IBIC system has been developed which uses a high-speed waveform digitiser to capture the pulse shapes produced by interactions of a 1 μm resolution scanning microbeam in semiconductor samples. Using a variety of digital pulse shape analysis algorithms, quantitative images of charge signal amplitude, charge carrier lifetime, mobility and trapping phenomena can be acquired in real-time, with a time resolution of <20 ns. We report data from the commissioning experiment which shows digital IBIC images of electron and hole transport in CdZnTe radiation detectors, obtained by lateral scanning of the ion beam between the cathode and anode. The room temperature electron drift mobility in CdZnTe was measured with a value of 1.1x10³ cm²/Vs