Updated physics design of the DAEdALUS and IsoDAR coupled cyclotrons for high intensity H2+ beam production

TL;DR

This paper presents an updated physics-based design for high-intensity H2+ beam production in coupled cyclotrons, crucial for neutrino experiments, supported by prototype tests and realistic beam simulations.

Contribution

It introduces a new design for high-current H2+ cyclotrons, demonstrating feasibility through prototype testing and advanced simulations.

Findings

Feasibility of accelerating 5 mA H2+ to 60 MeV/amu

Clean extraction of high-current H2+ beams demonstrated

Design supports neutrino experiment requirements

Abstract

The Decay-At-rest Experiment for delta-CP violation At a Laboratory for Underground Science (DAEdALUS) and the Isotope Decay-At-Rest experiment (IsoDAR) are proposed experiments to search for CP violation in the neutrino sector, and "sterile" neutrinos, respectively. In order to be decisive within 5 years, the neutrino flux and, consequently, the driver beam current (produced by chained cyclotrons) must be high. H2+ was chosen as primary beam ion in order to reduce the electrical current and thus space charge. This has the added advantage of allowing for stripping extraction at the exit of the DAEdALUS Superconducting Ring Cyclotron (DSRC). The primary beam current is higher than current cyclotrons have demonstrated which has led to a substantial R&D effort of our collaboration in the last years. We present the results of this research, including tests of prototypes and highly realistic beam simulations, which led to the latest physics-based design. The presented results suggest that it is feasible, albeit challenging, to accelerate 5 mA of H2+ to 60 MeV/amu in a compact cyclotron and boost it to 800 MeV/amu in the DSRC with clean extraction in both cases.