Y. Poltoratska

Reactions with polarized electrons and photons at low momentum transfers at the superconducting Darmstadt electron linear accelerator S-DALINAC

A source of polarized electrons has been installed at the superconducting Darmstadt electron linear accelerator S-DALINAC. Experiments with polarized electrons from 100 keV to about 80 MeV are expected to commence in early 2011. This contribution summarizes the status of the polarized source as well as ongoing preparations for the experimental program with polarized beams. In particular, we present results on unpolarized test experiments of the 234,238 U(γ,f) reactions and considerations for the 2 D(� e,ep) and 3 He(� e,ep) reactions.

Status and recent developments at the polarized-electron injector of the superconducting Darmstadt electron linear accelerator S-DALINAC

At the superconducting Darmstadt electron linac a 100 keV source of polarized electrons has been installed. Major components had been tested prior to installation at an offline teststand. Commissioning of the new source at the S-DALINAC will take place early in 2011. We report on the performance of the teststand, simulations, developments on the laser systems, new radio-frequency components for the S-DALINAC injector, and the status of the implementation of the source.

Polarized Electrons in Darmstadt: Recent Developments

The injector of the superconducting Darmstadt electron linear accelerator S‐DALINAC will soon be extended by a source of polarized electrons. A test set‐up of the future source consists of a 100 keV GaAs polarized gun and associated beamline including an assembly for polarization manipulation and determination. We give a short overview of the existing and planned polarimeters at the different accelerator sites, introduce briefly the future implementation of the polarized source at the S‐DALINAC and list experiments that are planned with polarized electron and photon beams.

Utilizing a wien filter within the beam dynamics simulation tool V-code

Beam dynamics simulations for computationally large problems are challenging tasks. On the one hand, for the accurate simulation the electromagnetic field distribution within the whole device and the surrounding environment, it is essential to consider all necessary device components including even small geometry details, complicated material distributions and the field excitations. On the other hand, additional computational effort has to be put into precise modeling of the injected particle beam for accurate beam dynamics simulations. Under linear conditions, it is possible to separate the field calculation of the device from the computation of the particles self-field which can result in the proper application of diverse numerical schemes for the individual field contributions. In the paper, a technique is presented by means of which the static electric and magnetic fields of a Wien filter beam line element can be treated as applied external fields within the beam dynamics simulation tool V-code under the assumption that the interaction of the particle beam with the surrounding materials can be neglected.

Polarization Of The High‐Energy End Of The Electron‐Nucleus Bremsstrahlung In Electron‐Atom Collisions

The linear polarization of bremsstrahlung radiation emitted in collisions of spin‐polarized and unpolarized electrons with carbon and gold targets has been measured for an incident kinetic energy of 100 keV. We present preliminary results for the degree of linear polarization for incident unpolarized electrons as a function of bremsstrahlung photon energy.

Status Report of the New Darmstadt Polarized Electron Injector

We present the status of the polarized injector for the superconducting Darmstadt electron linear accelerator S‐DALINAC. An offline teststand of the source was built to test all components of the S‐DALINAC polarized injector SPIN. The new electron source will deliver a 100 keV polarized beam and complement the present thermionic source operating at 250 kV. Results of the beam properties measurements will be introduced and an outlook on the upcoming installation of the new injector at the S‐DALINAC will be given.

ELECTRON BEAM POLARIMETRY AT LOW ENERGIES AND ITS APPLICATIONS

Low energy (E-k similar to 100 keV) Mott scattering polarimetry is a widely established technique to measure the polarization of an electron beam. We analyze the feasibility of Mott scattering at e ...

Polarized Electrons for Experiments at Low Momentum Transfer SPIN @ S‐DALINAC

The superconducting Darmstadt linear electron accelerator S‐DALINAC will be expanded by a newly developed polarized injector concept called SPIN. The polarized beam program includes experiments to search for parity violation in photo induced fission, the investigation of the 5th structure function at low momentum transfer and break up reactions of few body systems. These experiments and an overview of the current experiemental program will be covered in this paper.

Polarimetry at the Superconducting Darmstadt Electron Linac S‐DALINAC

A spin polarized electron source will be installed at the S‐DALINAC to extend the existing experimental capabilities polarization. In order to manipulate and monitor the beam polarization a Wien filter and different polarimeters will be installed. The already installed Wien filter and 100 keV Mott polarimeter and the planned 5 MeV Mott, 30–130 MeV Mo/ller and Compton transmission polarimeters are described.

Photo‐fission at the S‐DALINAC

Experiments on photo-induced fission of 238U and 234U using bremsstrahlung with endpoint energies between 6 MeV and 9 MeV have been carried out at the superconducting Darmstadt electron linear acce ...