K x rays produced in collisions of bare ions with atoms: Contribution of multiple-electron transfer in Kr³⁶⁺, Ar¹⁸⁺, and Ne¹⁰⁺+Ar collisions

K x rays have been observed in low energy collisions of bare Kr, Ar, and Ne ions with a neutral gas target. Although largely neglected previously, we have found that multiple-electron transfer processes play a significant role in shaping the x-ray spectra. The observed ratios of normal-satellite to hyper-satellite line intensities are found to be roughly independent of the ion species and much larger than those estimated from previously reported electron transfer cross sections, suggesting that there may be a strong correlation between two electrons during the electron transfer or during the subsequent cascades. It is suggested that exact knowledge of the initial and final principal and angular momentum quantum numbers (n,l) in electron transfer are the most essential missing ingredients for understanding the entire x-ray emission process in astrophysical, laboratory, and technological plasmas

Measurement of the NIEL-scaling factor of thick target p+Be neutrons at Ep = 17.4 MeV proton energy for silicon

Radiation tolerance tests of silicon based devices are regularly done at ATOMKI with thick target p+Be neutrons at Ep = 17.4 MeV. Measurements were done to estimate their NIEL-scaling factor for silicon. The neutron spectrum was measured by the multifoil activation technique. Saturation activities of different neutron induced reactions were measured and the neutron spectrum was unfolded from them. Displacement KERMA data were taken from literature and their energy spectrum averaged value was calculated. The obtained NIEL-scaling factor was = 1.1 ± 0.20. Following the ASTM E1855-05el standard, a second type of measurement was done, too. 2N2222 bipolar transistors were irradiated by p+Be neutrons and by fission neutrons. The emitter current gain of the transistors was measured before and after the irradiation. The NIEL-scaling factor could be determined from the differences of the gains using the Messenger-Spratt equation. The obtained NIEL-scaling factor was 1.1 ± 0.23 from this measurement

Astrophysics and spectroscopy with microcalorimeters on an electron beam ion trap

The importance of the combination of electron beam ion trap (EBIT) spectroscopy with X-ray microcalorimeters in the field of astrophysics was discussed. X-ray astronomy involves heavily charged ion instruments , especially EBIT, to obtain improved quality atomic data. In this regard, the research program at the National Institute of Standards and Technology, which uses X-ray spectroscopic methods to study plasma and atomic physics, was also discussed

Technical Design Report for the: PANDA Straw Tube Tracker

This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the PANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM-stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy-loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole \Panda scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described

Technical design report for the PANDA (AntiProton Annihilations at Darmstadt) Straw Tube Tracker

<p>This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the PANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole PANDA scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.</p>

Eperimental access to Transition Distribution Amplitudes with the PANDA experiment at FAIR

We address the possibility of accessing nucleon-to-pion (πN) Transition Distribution Amplitudes (TDAs) from p¯p→e+e−π0 reaction with the future \={P}ANDA detector at the FAIR facility. At high center of mass energy and high invariant mass of the lepton pair q2, the amplitude of the signal channel p¯p→e+e−π0 admits a QCD factorized description in terms of πN TDAs and nucleon Distribution Amplitudes (DAs) in the forward and backward kinematic regimes. Assuming the validity of this factorized description, we perform feasibility studies for measuring p¯p→e+e−π0 with the \={P}ANDA detector. Detailed simulations on signal reconstruction efficiency as well as on rejection of the most severe background channel, {\it i.e.} p¯p→π+π−π0 were performed for the center of mass energy squared s=5 GeV2 and s=10 GeV2, in the kinematic regions 3.00.5 in the proton-antiproton center of mass frame. Results of the simulation show that the particle identification capabilities of the \={P}ANDA detector will allow to achieve a background rejection factor at the level of 108 (2⋅107) at low (high) q2 while keeping the signal reconstruction efficiency at around 40% and that a clean lepton signal can be reconstructed with the expected statistics corresponding to 2 fb−1 of integrated luminosity. The future measurement of the signal channel cross section with \={P}ANDA will provide a new test of perturbative QCD description of a novel class of hard exclusive reactions and will open the possibility of experimentally accessing πN TDAs