Achim Richter

TL;DR: In this paper, experimental and numerical investigations of the influence of short pulse effects occurring in FELs in different operational regimes for electron bunch lengths which are of the order of the slippage distance.

TL;DR: In this paper, heavy reaction products resulting from central collisions in the mass-symmetric system 40 Ar+40 Ca were studied at an incident energy of 20 MeV/u.

TL;DR: In this article, the statistical properties of the electric pygmy dipole resonance in four different isotones with neutron number N = 82 were studied, i.e., in between the predictions of random matrix theory for correlated and uncorrelated spectra.

TL;DR: In this paper, the S-DALINAC polarization of channeling radiation from 65 MeV electrons in silicon has been measured for transitions between discrete transversal bound states for the first time.

Abstract: The S-DALINAC is a recirculating superconducting electron linac operating at 3 GHz. The accelerator delivers a cw beam with energies up to 130 MeV to serve electron scattering experiments where highest momentum resolutions, typ. below 10 -4 and excellent beam qualities are required. Current activities aim to reduce the energy spread of the beam of the accelerator by two methods: Long term drifts, mainly a result of temperature drifts, will be corrected by a feedback system which measures the energy variation of the extracted beam continuously using rf monitors. By means of time-of-flight analysis in a modified beamline a correction signal can be generated as a feedback for the rf control of the accelerating cavities. This system was set-up recently and first results will be reported. Furthermore, the influence of short term fluctuations, e.g. triggered by microphonics, on the electron energy can significantly be reduced utilizing the inherent stability of a microtron if the synchronous phase and longitudinal dispersion are chosen properly. The concept, particle simulations and the experimental verification will be shown as well as necessary modifications to the recirculation scheme to use it in an all-day operation.