Electron Scattering in Intrananotube Quantum Dots

Intratube quantum dots showing particle-in-a-box-like states with level spacings up to 200meV are realized in metallic single-walled carbon nanotubes by means of low dose medium energy Ar irradiation. Fourier transform scanning tunneling spectroscopy compared to results of a Fabry-Perot electron resonator model yields clear signatures for inter- and intra-valley scattering of electrons confined between consecutive irradiation-induced defects (inter-defects distance < 10nm). Effects arising from lifting the degeneracy of the Dirac cones within the first Brillouin zone are also observed

Concept for controlled transverse emittance transfer within a linac ion beam

For injection of beams into circular machines with different horizontal and vertical emittance acceptance, the injection efficiency can be increased if these beams are flat, i.e. if they feature unequal transverse emittances. Generation of flat electron beams is well known and has been demonstrated already in beam experiments. It was proposed also for ion beams that were generated in an Electron Cyclotron-Resonance (ECR) source. We introduce an extension of the method to beams that underwent charge state stripping without requiring their generation inside an ECR source. Results from multi-particle simulations are presented to demonstrate the validity of the method.Comment: 23 pages (preprint style), 14 Figures, submitted to PRST-A

Rotating system for four-dimensional transverse rms-emittance measurements

Knowledge of the transverse four-dimensional beam rms-parameters is essential for applications that involve lattice elements that couple the two transverse degrees of freedom (planes). Of special interest is the removal of inter-plane correlations to reduce the projected emittances. A dedicated ROtating System for Emittance measurements (ROSE) has been proposed, developed, and successfully commissioned to fully determine the four-dimensional beam matrix. This device has been used at the High Charge injector (HLI) at GSI using a beam line which is composed of a skew quadrupole triplet, a normal quadrupole doublet, and ROSE. Mathematical algorithms, measurements, and results for ion beams of 83Kr13+ at 1.4 MeV/u are reported in this paper.Comment: 11 pages, 10 figure

Measurement of UNILAC and SIS18 proton performance

On July 16th 2016 the UNILAC and SIS18 proton performance has been measured. Due to scheduled maintenance works of the UNILAC's rf-system, the post-stripper energy was restricted to 5.9~MeV and accordingly the beam quality suffered considerably from the interruption of the periodic focusing system. This limitation will not be any longer in future beam times. Six single-gap resonators were used for acceleration to 10.7~MeV. After an optimization of the multi-turn injection $\pmb{1.2\cdot10^{11}}$ protons were extracted form the SIS18

Status of the emittance transfer experiment emtex

In order to improve the injection efficiency of the round UNILAC heavy ion beam into the asymmetric acceptance of the SIS18 it would be of great advantage to decreasethe horizontal emittance by a so called emittance transferto the vertical plane. In this contribution the present statusof the emittance transfer experiment EMTEX at GSI will be reported. A short introduction about the theoretical background of the technique will be given, while the mainpart is dedicated to the practical solutions setting up a testbeam line at GSI. Finally, the results of a first commissioning beam time will be presented. The scheduled beam time to apply the emittance transfer technique foreseen in spring 2014 had to be shifted to calendar week 26 in 2014, just after this conference as some components have not been delivered in time by the contractor. The results and comparison to the theoretical predictions you may find in later publications