arXiv subjects

U. Velte

Publications and source records attributed to U. Velte.

4 recordsLinked to original sources

arXiv2013

Differential atom interferometry with $^{87}$Rb and $^{85}$Rb for testing the UFF in STE-QUEST

In this paper we discuss in detail an experimental scheme to test the universality of free fall (UFF) with a differential $^{87}$Rb / $^{85}$Rb atom interferometer applicable for extended free fall of several seconds in the frame of the STE-QUEST mission. This analysis focuses on suppression of noise and error sources which would limit the accuracy of a violation measurement. We show that the choice of atomic species and the correctly matched parameters of the interferometer sequence are of utmost importance to suppress leading order phase shifts. In conclusion we will show the expected performance of $2$ parts in $10^{15}$ of such an interferometer for a test of the UFF.

physics.atom-ph↗

arXiv2010

A simple method for generating Bose-Einstein condensates in a weak hybrid trap

We report on a simple novel trapping scheme for the generation of Bose-Einstein condensates of $^{87}$Rb atoms. This scheme employs a near-infrared single beam optical dipole trap combined with a weak magnetic quadrupole field as used for magneto-optical trapping to enhance the confinement in axial direction. Efficient forced evaporative cooling to the phase transition is achieved in this weak hybrid trap via reduction of the laser intensity of the optical dipole trap at constant magnetic field gradient.

cond-mat.quant-gas↗

arXiv2009

Beam Polarization at the ILC: the Physics Impact and the Accelerator Solutions

In this contribution accelerator solutions for polarized beams and their impact on physics measurements are discussed. Focus are physics requirements for precision polarimetry near the interaction point and their realization with polarized sources. Based on the ILC baseline programme as described in the Reference Design Report (RDR), recent developments are discussed and evaluated taking into account physics runs at beam energies between 100 GeV and 250 GeV, as well as calibration runs on the Z-pole and options as the 1TeV upgrade and GigaZ.

physics.acc-ph↗

arXiv2007

Simulation Studies and Detector Scenarios for an ILC Polarimeter

High energy longitudinal electron polarimetry will be based on Compton scattering for the International Linear Collider. An unobtrusive measurement has to include a magnet chicane setup serving as a spectrometer. Current proposals make use of Cerenkov detectors for electron detection. A fast simulation has been developed to study the basic properties of scenarios for the polarimeter setup.

physics.ins-det↗