Speaker
Description
After the discovery of the Lamb shift in 1947 by Willis Eugene Lamb and Robert C. Retherford it was used to create Lamb shift polarimeter to separate the 2S$_{1/2}$ α$_1$ and α$_2$ hyperfine substates of hydrogen as well as the α$_3$ substate of deuterium. But for a new project at the Technical University of Munich, the bound-beta decay of a neutron into a hydrogen atom and a neutrino, a Lamb shift polarimeter is needed that is also capable of separating the β$_3$ substate of hydrogen. Unfortunately, our first attempt to use a Sona transition unit to exchange the occupation numbers between α$_1$ and β$_3$ failed, because of the unexpected complexity of the transitions in this unit. The second idea of using a new kind of spinfilter which uses two radio frequencies to separate all four hyperfine substates of hydrogen also failed.
Our third attempt is now to build a transition unit that can induce magnetic dipole transitions between α$_2$ and β$_3$ as well as between α$_1$ and β$_4$ (π transitions). This transition unit should use a magnetic gradient field and a radio frequency to induce direct transitions between two hyperfine substates without oscillations with one of the 2P$_{1/2}$ substates. This is a similar transition like use in atomic beam sources, in this case not for ground state but for metastable atoms, which leads to a much lower radio frequency. Another difference of this new idea is the smaller interaction time of the atoms with the photons inside the transition unit due to their much higher velocity of roughly 5⋅105 m/s compared to velocities of about 103 m/s after an atomic beam source.
| Category | Polarimetry |
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