Prof. Dr. Stephan Paul
Lehrveranstaltungen und Termine
Ausgeschriebene Angebote für Abschlussarbeiten
- Production and detection of meta-stable hydrogen atoms
Context: The neutron decay is for many years subject of intense studies, as it reveals detailed information about the structure of the weak interaction. Using the two-body neutron decay into a hydrogen atom and an electron antineutrino n → H + the hyperfine population of the emerging hydrogen atom can be investigated.
Some of the produced hydrogen atoms (~ 10%) are in the meta-stable state 2S.
This special hydrogen atoms from the neutron decay are almost mono-energetic (325.7 eV), because of the nature of the two-body decay.
In a first step we want to develop techniques to detect these special H(2S) atoms and analyze their properties (energy and hyperfine states).
We have recently constructed and built a time-of-flight setup (Bradbury-Nielsen gate chopper) with a strong proton source, by means of which we can measure the energy of charged particles with a resolution in the eV- region.
H(2S) can also be produced with protons, if they are passing a region with low pressure Cs-vapor. These atoms can be transformed in H- by interaction with Ar- vapor.
The 2S state can be detected by quenching the atom with the aid of an electric field to the 1S state. The emitted Lyman-alpha photons can be detected with a special photomultiplier. The H- atoms can be measured with a magnetic spectrometer or an electrostatic deflector.
All measurements with charged/neutral particles are done with a multi-channel-plate detector.
The working program of this master thesis is divided in:
- Set up the Cs- and Ar- vapor system in the existing proton beam line
- Set up of the quenching system with the photomultiplier
- Design of the electrostatic deflector system (CAD and calculations with a beam optic program like TRANSPORT)
- Measurements with the new setup.
- Determination of the charge transfer cross section of argon for H(2S) atoms for energies lower than 500 eV.
- Development of a electrostatic deflector spectrometer
- Optimization of a quenching system for H(2S) atoms
- geeignet als
- Masterarbeit Kern-, Teilchen- und Astrophysik
- Themensteller(in): Stephan Paul