Speaker
Description
New facilities like FAIR at GSI or SPIRAL2 at GANIL, will permit to provide radioactive ion beams at low energies (less than 10 MeV per nucleon). Such beams have generally a large emittance, which requires the use of beam tracking detectors to reconstruct the exact trajectories of the nuclei. To reduce the angular and energy straggling that classical beam tracking detectors would generate in the beam due to their thickness, we propose the use of SED (Secondary Electron Detectors). The detector studied in this work consists in a low pressure gaseous chamber (below 10 mbar) placed outside the beam coupled to an emissive foil in the beam. Different low pressure gaseous detectors (wire chambers and micromegas) have been constructed and tested for several years at GANIL. The performances achievable at very low pressure are similar or even better than at atmospheric pressure. The fast charge collection leads to excellent timing properties as well as high counting rate capabilities even for a wire chamber. The spatial, temporal and counting rate performances of the final detector were measured both with radioactive source and a 238U beam. The results demonstrate the good functioning of the detection system as well as its suitability and adaptability to the detectors to which it will be coupled. Time and spatial resolutions below 150 ps and 0.5 mm, have been achieved, respectively, even at high counting rates. A comparison of CF4 and iC4H10 was also performed, including systematic gain measurement, providing new insights concerning the behavior of these gases at very low pressure.
| Name of the speaker | Julien Pancin |
|---|---|
| Eligible for the Georges Charpak Young Scientist Award. | no |