Beam tests of the PIP-II Injector Test Radio Frequency Quadrupole

Abstract

In modern high intensity ion–particle accelerators, a Radio Frequency Quadrupole (RFQ) is utilized to prepare a high-quality beam for injection to the main accelerating section. Since an RFQ governs the initial beam parameters, characterization of the beam coming out from the RFQ is foremost step toward commissioning of an accelerator facility. It allows validating the RFQ design as well as attaining a better understanding of charged-particle beams. This paper describes the beam-performance of the Proton Improvement Plan-II Injector Test (PIP2IT) Continuous Wave (CW) four vane-type RFQ. It is designed to operate at a frequency of 162.5 MHz and accelerate a nominal H− beam of 5 mA from 30 keV to 2.1 MeV. The paper details beam tests performed to validate the RFQ design specifications for transmission, beam kinetic energy and, RMS emittances. The paper also presents beam profile measurements and implication of the beam-jitters on the effective beam emittance at the RFQ exit.