Trapping and cooling of (anti)hydrogen

William D. Phillips, S. L. Rolston, Paul D. Lett +3 more

Gregory P. Kochanski

Luiten, O.J., Werij, H.G.C., Reynolds, M.W. +3 more

O.J. Luiten, H. G. C. Werij, M. W. Reynolds +3 more

C L Taylor, Jingjing Zhang, F. Robicheaux

We have simulated the centre-of-mass motion of Rydberg anti-hydrogen atoms in spatially varying magnetic fields. We find that a population of anti-hydrogen can lose substantial centre-of-mass kinetic energy during the radiative cascade to the ground state. The loss of energy is due to the change in magnetic moment when photons are emitted and is akin to adiabatic cooling. We also simulate the pattern of anti-hydrogen hits on the walls of the trap and find that the existence of trapped Rydberg atoms leads to a distinctive distribution along the trap axis.

N. Evetts

Precise spectroscopic measurements of anti-hydrogen at the ALPHA experiment are hindered by small numbers of cold anti-atoms. This thesis describes a cooling technique for positron plasmas which can be used to increase the number of trappable anti-hydrogen atoms. The technique builds on previous work which allows control of spontaneous emission via the Purcell Effect. Our implementation incorporates a novel microwave resonator into an existing Penning trap to enhance spontaneous emission. Preliminary data suggests that temperatures and cooling rates for these plasmas can be improved by at least a factor of 10. Eventually this work could result in an order of magnitude increase in anti-hydrogen production at ALPHA.