N. Zaganidis

Study of straw proportional tubes for a transition radiation detector/tracker at LHC

Abstract The most relevant properties for operation of straw proportional tubes at LHC are described. Particular attention is paid to the possibility of straw operation in a strong magnetic field and a high radiation environment.

Mapping of [3H]vasopressin binding sites in the brain of jerboa (Jaculus orientalis) by an high resolution β-radio imager

The distribution of vasopressin receptors in the brain of the jerboa (Jaculus orientalis) was studied using tritiated arginin vasopressin ([3H]vasopressin). beta-Particles emitted from tritiated ligand bound to brain sections were detected by a newly developed beta-radio imager to generate a light spot which was read by a charge coupled device camera. The number and coordinate of the center of gravity of the light spot were recorded. After summation in pixels of the counts collected during 2-20 h, an image was produced representing the distribution of [3H]vasopressin bound to brain sections. Specific vasopressin binding was detected in various brain regions such as the cerebral cortex, islands of Calleja, pallidum, amygdala and the hippocampus as well as in the pituitary gland. The intensity of the binding was quantified directly from the images obtained and expressed in decays/min/surface unit. The linearity of this method of detection allowed a relevant measurement of non-specific binding, therefore its subtraction from images representing the total binding. Three-dimensional reconstructions of labeled structures were also performed. The presence of numerous vasopressin receptors in the jerboa hippocampus suggests a major role for this neuropeptide in this part of the brain.

Particle identification performance of a straw transition radiation tracker prototype

Abstract An 864 channel prototype of an integrated straw tracker and transition radiation detector for tracking and electron identification has been tested with and without magnetic field at the CERN SPS. The rejection against hadrons and converted photons has been measured and the dependence of the rejection power on detection parameters has been investigated. Tracking and hadron rejection were also studied in a high multiplicity environment. The results are compared with Monte Carlo simulations. Wherever possible, conclusions are drawn concerning the performance of a full-scale detector at the future Large Hadron Collider.

Development of a RICH detector for ultrarelativistic heavy ion collisions

Abstract A single module of an intended RICH detector for ultrarelativistic heavy ion collisions (NA35 experiment at CERN) has been tested with 1.5–3 GeV/ c positive hadrons. The Cherenkov photons from a liquid freon (C 6 F 14 ) radiator have been focused by a spherical mirror into a multistep avalanche chamber equipped with an optical readout. The analysis of the events and the results of the reconstruction of the Cherenkov angle are presented. A good agreement between experiment and simulation was observed.

A 50 × 50 CM2 rich detector prototype for ultrarelativistic heavy ion collisions

Abstract A 50 × 50 cm2 RICH detector was tested with hadron beams of 200 GeV/c to determine the resolution and efficiency of the system. Single photon detection has been achieved with a multistep avalanche chamber in conjunction with a CCD camera equipped with a 35 mm f 1.4 lens coupled to a two stage image intensifier. The results show that for the number of photons detected with the present setup and the geometry used in proximity focusing a standard deviation of 7.5 mrad per event has been achieved for the reconstruction of the Cherenkov angle.