Open microwave cavity for use in a Purcell enhancement cooling scheme

Amicrowavecavity is described which can be used to cool lepton plasmas for potential use in synthesis of antihydrogen. The cooling scheme is an incarnation of thePurcell effect: when plasmas are coupled to amicrowavecavity, the plasma cooling rate isresonantly enhanced through increased spontaneous emission of cyclotron radiation. Thecavity forms a threeelectrode section of a Penning-Malmberg trap and has a bulged cylindrical geometry with open ends aligned with the magnetic trapping axis. This allows plasmas to be injected and removed from thecavity without the need for moving parts while maintaining high quality factors forresonant modes. Thecavity includes uniquesurface preparations for adjusting thecavity quality factor and achieving anti-static shielding using thin layers of nichrome and colloidal graphite, respectively. Geometric design considerations for acavity with strong cooling power and low equilibrium plasma temperatures are discussed.Cavities of this weak-bulge design will be applicable to many situations where an open geometry is required.

Source: Review of Scientific Instruments - October 3, 2016 Category: Physics Authors: N. Evetts, I. Martens, D. Bizzotto, D. Longuevergne and W. N. Hardy Source Type: research