A new method to measure the beta function in a Paul trap

L K Martin,K Ito,H Okamoto,D J Kelliher,S L Sheehy,S Machida

doi:10.1088/1742-6596/1067/6/062016

L K Martin, K Ito + Show 4 more

Open Access

https://doi.org/10.1088/1742-6596/1067/6/062016

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Abstract

The Simulator of Particle Orbit Dynamics (S-POD) is a linear Paul trap at Hiroshima University, Japan, used to study beam physics. S-POD has so far been used to study resonances in high intensity beams, predominantly using a simple alternating gradient lattice configuration. Recently a similar apparatus, the Intense Beam Experiment (IBEX), has been constructed at the Rutherford Appleton Lab in the UK. To use either of these experiments to study beam dynamics in more complex lattice configurations in the future, further diagnostic techniques must be developed for Paul traps. Here we describe a new method to measure the beta function and emittance in a Paul trap.

Highlights

The Simulator of Particle Orbital Dynamics (S-POD), at Hiroshima University, Japan, is a linear Paul trap (LPT) which confines ions in an rf electric quadrupole potential
It has been shown that the Hamiltonian of ions in the laboratory frame of the Paul trap is equivalent to that of particles moving in a high intensity beam traveling through an alternating gradient lattice, so that transverse motion in the two systems is equivalent [1]
This paper explores a new method to extract the emittance and beta function experimentally at a given time in the S-POD LPT

Summary

INTRODUCTION

The Simulator of Particle Orbital Dynamics (S-POD), at Hiroshima University, Japan, is a linear Paul trap (LPT) which confines ions in an rf electric quadrupole potential. We have developed a new method to measure the beta function and emittance at a specific point in time in the S-POD LPT by applying a dipole kick to the trapped ions. When a single kick is applied, the equation describing the resulting transverse motion is Figure 2: Schematic end view of SPOD rods showing the voltages applied in the beta function measurement. Applying the dipole perturbation at different points in the confining potential leads to a varying transverse displacement and varying beam loss, allowing a beta function measurement. To do this a gaussian beam is assumed, this has been validated previously in [8].

MEASUREMENT METHOD

RESULTS

DISCUSSION