Smoothing of the slowly extracted coasting beam from a synchrotron

TL;DR

This paper introduces a method to smooth the beam extracted from a synchrotron by modulating quadrupole currents, reducing power supply fluctuation effects and improving detector data quality.

Contribution

It proposes and experimentally demonstrates a novel modulation technique on quadrupole currents to mitigate power supply fluctuations during slow extraction.

Findings

Beam modulation reduces detector pile-ups.

Enhanced stability of the extracted beam.

Improved statistical quality of experimental data.

Abstract

Slow extraction of beam from synchrotrons or storage rings as required by many fixed target experiments is performed by controlled excitation and feeding of a structural lattice resonance. Due to the sensitive nature of this resonant extraction process, the temporal structure of the extracted beam is modulated by the minuscule current fluctuations present on the quadrupole magnet power supplies. Such a modulation lead to pile-ups in detectors and a significant reduction in accumulated event statistics. This contribution proposes and experimentally demonstrates that by an introduction of further modulation on quadrupole currents with a specific amplitude and frequency, the inherent power supply fluctuations are mitigated leading to a smoothening of the beam temporal structure. The slow extraction beam dynamics associated with this method are explained along with the operational results.