Optimization of Superconducting Linac for Proton Improvement Plan-II (PIP-II)

TL;DR

This paper presents a comprehensive optimization and analysis of the PIP-II superconducting linac, focusing on beam quality, loss control, and the effects of nonlinear fields to ensure efficient high-power proton acceleration for neutrino experiments.

Contribution

It introduces a global optimization approach for the PIP-II linac design, analyzes the impact of nonlinear dipole fields, and evaluates methods to control beam coupling and focusing.

Findings

Optimized linac parameters for high-power operation.

Quantified the impact of nonlinear dipole fields on beam quality.

Identified strategies for controlling beam coupling and focusing issues.

Abstract

PIP-II is an essential upgrade of the Fermilab complex that will enable the worlds most intense high-energy beam of neutrinos for the international Deep Underground Neutrino Experiment at LBNF and support a broad physics program at Fermilab. Ultimately, the PIP-II superconducting linac will be capable of accelerating the $H-$ CW beam to 800 MeV with an average power of 1.6 MW. To operate the linac with such high power, beam losses and beam emittance growth must be tightly controlled. In this paper, we present the results of global optimization of the Linac options towards a robust and efficient physics design for the superconducting section of the PIP-II linac. We also investigate the impact of the nonlinear field of the dipole correctors on the beam quality and derive the requirement on the field quality using statistical analysis. Finally, we assess the need to correct the quadrupole focusing produced by Half Wave, and Single Spoke accelerating cavities. We assess the feasibility of controlling the beam coupling in the machine by changing the polarity of the field of linac focusing solenoids