Transmission Efficiency of the Recoil Mass Spectrometer EMMA at TRIUMF
arXiv:2511.05643 · doi:10.1016/j.nima.2026.171295
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.
18 pages, 17 figures, revised version with fewer typographical errors accepted for publication in Nucl. Instrum. Meth. Phys. Res. A