A novel, multiple-electrode penning trap
Graessle, Scott Christian
Bonner, Billy E.
Master of Arts
As part of an eventual experiment to measure the gravitational acceleration of the antiproton, we have designed, constructed and tested an extended-length, harmonic Penning-type ion trap. A distributed-electrode design allows the radial inside dimension to be kept at a minimum (1 $cm$) while extending the axial length to 15 $cm$. In-flight capture of 10-$keV$ protons from a continuous-beam ion source has been achieved. A storage time decay constant of 4.78 $\pm$ 1.25 $s$ has been observed and is shown to be dominated by losses due to collision with the residual gas. Resonant excitation of the axial motion of the trapped ions has demonstrated the harmonicity of the trap in both the linewidth of the resonance and the agreement between observed and calculated frequency of axial motion for protons in the harmonic well. The harmonic quality factor $Q$ = $f$/$\Delta f$ is observed to be 120. Systematic uncertainties allow for agreement of the observed capture efficiency with the expected 100%, although future work will be necessary. Possible future improvements to the system, some already implemented, are mentioned.
Particle physics; Elementary particles; High energy physics