Kinematics Calibration and Excitation Energy Reconstruction for Solenoidal Spectrometers

This work introduces a novel method for reconstructing excitation energy and center-of-mass scattering angle from energy-position data in solenoidal spectrometers, addressing challenges posed by non-linearities at small scattering angles. The approach employs a robust calibration of experimental energy-position data using known excited states, followed by an analytical inverse transformation based on relativistic kinematics and cyclotron motion. Integrated into the HELIOS online analysis routines, this method enables real-time generation of excitation energy spectra and angular distributions during experiments, improving efficiency and accuracy over traditional projection-based methods. The method's effectiveness is demonstrated using the 25Mg(d,p) reaction, highlighting its ability to handle forward-angle data and produce precise kinematic reconstructions.