Skip to Main content Skip to Navigation
Theses

Etude et mise en oeuvre d'un dispositif pour la mesure du paramètre de corrélation angulaire dans la désintégration du noyau Hélium6

Abstract : This thesis is about the design and the implementation of a device to guide ion beams. It is to be used to measure the angular correlation parameter in the decay of Helium6 ions confined in a Paul trap. The principle of the measurement is to detect in coincidence the emitted electron and recoil ion in order to reconstruct the complete kinematics on an event by event basis in the best possible conditions. Indeed, the experimental setup allows us to study ions almost at rest and confined in a small volume. The beta-neutrino angular correlation parameter is deduced from the coincidence spectrum and its value constitutes a test of the V-A structure of the weak interaction. The work presented here concerns mainly the characterization of the device for the reduction of the beam emittance : the radiofrequency quadripole with buffer gas. Ions lose energy by elastic collisions on the buffer gas atoms while being confined with help of an electric radiofrequency field. Tests have been done with stable ions which show on the one hand a very good agreement with simulations and, on the other hand, confirm the adequacy of the device. The cooled ions are then trapped inside the Paul trap with an efficiency of the order of 20 %. Finally, the obtained characteristics of the detection setup (efficiencies and resolutions) allow us to estimate the event statistics needed to reach the required precision on the angular correlation parameter.
Document type :
Theses
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00008061
Contributor : Guillaume Darius <>
Submitted on : Friday, January 14, 2005 - 3:58:51 PM
Last modification on : Tuesday, February 5, 2019 - 12:12:08 PM
Long-term archiving on: : Tuesday, September 7, 2010 - 5:16:09 PM

Identifiers

  • HAL Id : tel-00008061, version 1

Citation

G. Darius. Etude et mise en oeuvre d'un dispositif pour la mesure du paramètre de corrélation angulaire dans la désintégration du noyau Hélium6. Physique Nucléaire Théorique [nucl-th]. Université de Caen, 2004. Français. ⟨tel-00008061⟩

Share

Metrics

Record views

361

Files downloads

954