Kaltenbacher T, Caspers F, Doser M, Kellerbauer A, Pribyl W
Physics and Accelerator Departments, CERN, 1211 Geneva 23, Switzerland.
Rev Sci Instrum. 2011 Nov;82(11):114702. doi: 10.1063/1.3663610.
The paper addresses a novel method to couple a signal from charged particles in a Penning trap to a high Q resonant circuit using a crystal resonator. Traditionally, the trap capacity is converted into a resonator by means of an inductance. The tuned circuit's Q factor is directly linked to the input impedance "seen" by the trapped particles at resonance frequency. This parallel resonance impedance is a measure of the efficiency of resistive cooling and thus it should be optimized. We propose here a commercially available crystal resonator since it exhibits a very high Q value and a parallel resonance impedance of several MΩ. The possibility to tune the parallel resonance frequency of the quartz results in filter behavior that allows covering a range of some tens of its 3dB bandwidth by means of tuning.
