Transmission Efficiency of the Recoil Mass Spectrometer EMMA at TRIUMF

TL;DR

This paper measures and models the transmission efficiency of the EMMA recoil mass spectrometer at TRIUMF across various angles and energies, comparing experimental data with simulations.

Contribution

It provides empirical models of EMMA's transmission efficiency as functions of angle and energy, validated against measurements and simulations.

Findings

Transmission efficiency varies with angle and energy deviations.

Empirical Gaussian models fit the measured data well.

Comparison with ion-optical calculations and Monte Carlo simulations validates the models.

Abstract

The mean transmission efficiency of the EMMA recoil mass spectrometer at TRIUMF has been measured with 6 different angular apertures at 17 kinetic energy/charge deviations with respect to the central, reference trajectory. Measurements performed using a 148Gd alpha source installed at the target position of the spectrometer are compared to ion-optical calculations and Monte Carlo simulations. The transmission efficiency as a function of angle and kinetic energy/charge is described empirically using piecewise Gaussian functions whose parameters are fit to the data.