CALIBRATION OF SIMS MEASUREMENTS BY ION IMPLANTATION

The paper reviews some joint results of the above institutions in quantitative SIMS (Secondary Ion Mass Spectrometry) analysis of implanted dopants. Quantification of the SIMS was achieved by implanting marker ions as standards prior to analysis. Feasibility of this technique was first demonstrated by Giber et al. (1982). Further considerations will be presented

Theoretical investigation of carbon defects and diffusion in α-quartz

The geometries, formation energies, and diffusion barriers of carbon point defects in silica (α-quartz) have been calculated using a charge-self-consistent density-functional based nonorthogonal tight-binding method. It is found that bonded interstitial carbon configurations have significantly lower formation energies (on the order of 5 eV) than substitutionals. The activation energy of atomic C diffusion via trapping and detrapping in interstitial positions is about 2.7 eV. Extraction of a CO molecule requires an activation energy <3.1 eV but the CO molecule can diffuse with an activation energy <0.4 eV. Retrapping in oxygen vacancies is hindered—unlike for O2—by a barrier of about 2 eV

BEAM PARAMETERS AND CHARACTERIZATION TECHNIQUE

A review of the electrical and optical beam parameters is given. We describe our computer controlled, four slit beam characterization technique called computer controlled beam diagnostic CCBD system. The CCBD system can be operated in beam profile and emittance modes. The data collection is finished with appearance on the screen of the corresponding three-dimensional diagram: the current density map of x; x' and y; y' emittance maps. As a result of software manipulation further beam characteristics like current contours, emittance patterns, emittance as a function of beam fraction etc. can be deduced. The setup consists of four motorized, water cooled slits with variable slit width allowing to handle beams from muA up to hundreds of mA

PRELIMINARY-RESULTS ON THE ANTICYCLOTRON AT LEAR

The KfK 'Cylotron trap' has been modified to act as a declaration and trapping device for a large number of antiprotons. An active injection device (kicker) and a pair of pulsed extraction electrodes have been placed in the cyclotron cliamber. A cylindrical e.m. trap has been added in the axial bore of the cyclotron magnet and a separation membrane has been inserted to decouple the cyclotron chamber from the high-vacuum region of the trap. We report here preliminary results of a test of this apparatus, performed at the LEAR 72 MeV/c antiproton beam