H Bräuning

Performance of a position sensitive Si(Li) x-ray detector dedicated to Compton polarimetry of stored and trapped highly-charged ions

We report on a novel two-dimensional position sensitive Si(Li) detector dedicated to Compton polarimetry of x-ray radiation arising from highly-charged ions. The performance of the detector system was evaluated in ion-atom collision experiments at the ESR storage ringe at GSI, Darmstadt. Based on the data obtained, the polarimeter efficiency is estimated in this work.

Observation of the 2p3/2→2s1/2 intra-shell transition in He-like uranium

We present the first observation of the 1s2p 3P2→1s2s 3S1 transition in He-like uranium. The experiment was performed at the internal gas-jet target of the ESR storage ring at GSI exploiting a Bragg crystal spectrometer and a germanium solid-state detector. Using the 1s22p 2P3/2→1s22s 2S1/2 transition in Li-like uranium as reference and the deceleration capabilities of the ESR storage ring, we obtained the first evaluation of the energy of an intra-shell transition for a He-like heavy ion.

Double-electron capture in relativistic U92+ collisions at the ESR gas-jet target

Abstract Total cross-sections for radiative single- and double-electron capture are measured in collisions of fast highly charged ions with light target atoms. Cross-sections for non-correlated double capture are in accordance with theoretical predictions. No significant line structure at twice the single K-radiative electron capture (K-REC) photon energy was observed. Angular distributions single K-REC photons associated with single- and double-charge exchange exhibit the same pattern. The corresponding REC lines are almost by a factor of two broader for double-charge exchange than in the single capture case.

Compton polarimetry using double-sided segmented x-ray detectors

Hard x-ray polarimetry of radiation emitted in collisions of heavy ions, electrons or photons with matter provides detailed information on the collision dynamics as well as of the atomic structure in the presence of extreme field strengths. Moreover, it also opens a route for polarization diagnosis of spin-polarized ion and electron beams which, for example, might be useful in future parity non-conservation studies. Owing to recent progress in the development of highly segmented solid-state detectors, a novel type of polarimeter for the hard x-ray regime has become available. Applied as Compton polarimeters, two-dimensional position-sensitive x-ray detectors now allow for precise and efficient measurements of x-ray linear polarization properties. In this report recent polarimetry studies using such detector systems are reviewed.

Differential energy measurement between He- and Li-like uranium intra-shell transitions

We present the first clear identification and highly accurate measurement of the intra-shell transition

Monte Carlo simulations for the characterization of position-sensitive x-ray detectors dedicated to Compton polarimetry

1s2p\, ^3P_2 \to 1s2s\, ^3S_1

Polarization studies of radiative electron capture into highly-charged uranium ions

of He-like uranium performed via X-ray spectroscopy. The present experiment has been conducted at the gas-jet target of the ESR storage ring in GSI (Darmstadt, Germany) where a Bragg spectrometer, with a bent germanium crystal, and a Ge(i) detector were mounted. Using the ESR deceleration capabilities, we performed a differential measurement between the

Polarized tunable monoenergetic x-rays produced by radiative electron capture into the K-shell of Xe54+

1s2p\, ^3P_2 \to 1s2s\, ^3S_1

Polarization Measurements of Radiative Electron Capture Transitions in Highly Charged Ions

He-like U transition energy, at 4510 eV, and the

Employing digital pulse processing electronics for the readout of a Si(Li)—Compton—polarimeter for the SPARC collaboration

1s^22p\ ^2P_{3/2} \to 1s^22s\, ^2S_{1/2}