Contactless 2-dimensional laser sensor for 3-dimensional wire position and tension measurements

We have developed a contact-free 2-dimensional laser sensor with which the position of wires can be measured in 3 dimensions with an accuracy of better than 10 micrometer and with which the tension of the wires can be determined with an accuracy of 0.04 N. These measurements can be made from a distance of 15 cm. The sensor consists of commercially available laser pointers, lenses, color filters and photodiodes. In our application we have used this laser sensor together with an automated 3 dimensional coordinate table. For a single position measurement, the laser sensor is moved by the 3-dimensional coordinate table in a plane and determines the coordinates at which the wires intersect with this plane. The position of the plane itself (the third coordinate) is given by the third axis of the measurement table which is perpendicular to this plane. The control and readout of the table and the readout of the laser sensor were realized with LabVIEW. The precision of the position measurement in the plane was determined with wires of 0.2 mm and 0.3 mm diameter. We use the sensor for the quality assurance of the wire electrode modules for the KATRIN neutrino mass experiment. We expect that the precision is at least comparable or better if the wires are thinner. Such a device could be well suited for the measurement of wire chamber geometries even with more than one wire layer.Comment: 15 pages, 8 figure

Heating and Trapping of Electrons in ECRIS from Scratch to Afterglow

Plasmas in Electron Cyclotron Resonance Ion Sources (ECRIS) are collisionless and can therefore be simulated by just following the motion of electrons in the confining static magnetic and oscillating microwave (MW) electric field of ECRIS. With a powerful algorithm the three-dimensional trajectories of 104 ECR-heated and confined electrons are calculated in a standard ECRIS with a deep minimum of |B| and a new ECRIS with a very flat minimum of |B|. The spatial electron (plasma) densities and electron energy densities deduced from these trajectories yield new and surprising insight in the performance of ECRIS. With computer animation we plan to present: The energy increase of certain electrons on extremely stable trajectories, the power dependence of the electron energy density up to the X-ray collapse, the time dependent build up of the electron density and energy density distributions, and the time evolution of these electron distributions under afterglow conditions

High density cluster jet target for storage ring experiments

The design and performance of a newly developed cluster jet target installation for hadron physics experiments are presented which, for the first time, is able to generate a hydrogen cluster jet beam with a target thickness of above $10^{15}\,\mathrm{atoms/cm}^2$ at a distance of two metres behind the cluster jet nozzle. The properties of the cluster beam and of individual clusters themselves are studied at this installation. Special emphasis is placed on measurements of the target beam density as a function of the relevant parameters as well as on the cluster beam profiles. By means of a time-of-flight setup, measurements of the velocity of single clusters and velocity distributions were possible. The complete installation, which meets the requirements of future internal fixed target experiments at storage rings, and the results of the systematic studies on hydrogen cluster jets are presented and discussed.Comment: 10 pages, 18 figure

Successful modeling, design, and test of electron cyclotron resonance ion sources

Plasmas in electron cyclotron resonance ion sources (ECRIS) are collisionless and can therefore be simulated by only following the motion of electrons in the confining static magnetic and oscillating microwave field of ECRIS. The experimental performance of three different ECRIS is successfully compared to calculated spatial electron (plasma) and electron energy density as well as to the energy spectrum and the average energy of the electrons. Further simulations suggest a new and better design of an ECRIS, the good experimental performance of which corresponds to the predictions