This EAGER award provides funding for a first demonstration of the capture and acceleration of molecular hydrogen ions (H+2) in the central region of a cyclotron. This is the first step along the path to high-power, high-energy cyclotrons for use in basic science and with valuable industrial applications. The DAEdALUS Collaboration is designing advanced cyclotrons that accelerate H+2 ions to produce decay-at-rest neutrino beams in a novel search for Charge-Parity (CP) violation in the neutrino sector. Physicists at MIT and the Istituto Nazionale di Fisica Nucleare (INFN-Catania, Italy) are collaborating with Best Cyclotron Systems Inc., of Virginia. This award will provide funding for the university contribution. The required cyclotrons must exceed the performance of the world's best performing cyclotrons in both energy and power.
The effort is transformational -- advancing particle physics and accelerator driven technology for thorium-based reactors. The physics community has placed the search for CP-violation in the neutrino sector at the highest priority. CP Violation would be manifest as a difference in the oscillations of neutrinos versus antineutrinos. While conventional neutrino beams suffer from high systematic errors, the DAEdALUS multi-cyclotron design offers a statistics-limited alternative approach. Thus, this project has the potential to be transformational for the particle physics community. This project also has high intellectual merit for the cyclotron community. The DAEdALUS cyclotrons are consistent with the next crucial step in the art of cyclotron research. The measurements from a new H+2 ion source at the BEST Cyclotrons test stand, will allow the first publication of beam characteristics of high intensity H+2 acceleration.
Broader Impacts: The effort will train young accelerator scientists as well as better integrate cyclotron research into the particle physics community. High power accelerators are of interest to the nuclear reactor community for the purpose of accelerator driven systems (ADS) for thorium reactors and actinide incineration. This work represents a collaboration between MIT and European cyclotron experts. This technology transfer is a high priority for the U.S., as described in the DOE report entitled Accelerators for America's Future.
The purpose of this EAGER grant was to establish that high intensity H2+ beam could be produced by an ion source and successfully injected into a cyclotron. This is precursor R&D for the IsoDAR sterile neutrino search experiment. The work was performed at Best Cyclotron Systems, Incorporated and was a collaboration between MIT, INFN-Catania and Best Cyclotron Systems. The study resulted in two significant outcomes. First, we showed that up to 30 mA of H2+ will be producible from a Versitile Ion Source (VIS). This is close to the level of published H2+ production from multicusp ion sources. Thus, there are two potential ion source types that can produce high intensity beams of sufficient quality to inject into a cyclotron. Second, our success in injecting the beam allowed us to make detailed comparisons to simulations. The OPAL code, which is widely used to describe beam in cyclotrons with space charge effects, was adapted to allow for a 3-D model of spiral inflectors. We then benchmarked this code. This is an important advance in the simulations, which will be made available as open-source code, within the OPAL open source package. With this advance, we are now in a position to simulate the IsoDAR cyclotron system from start to end, a milestone which has been requested by reviewers. The high intellectual merit of this program is indicated by the alignment of this effort with the recommendations of the Particle Physics Program Prioritization Panel (P5). In recommendation 15, this group explicitly noted that IsoDAR should be included in consideration of short baseline experiments within the particle physics program. The results of this EAGER are crucial to this consideration. In recommendation 26, P5 noted the importance of university based accelerator science. And in recommendation 27, P5 noted the importance of young scientists gaining hands-one experience with hardware. Lastly, throughout the P5 recommendations, the importance of international collaboration was emphasized, as occurred during this EAGER. A purpose of the EAGER is to set up the collaboration for further, more standard proposals to NSF. This EAGER has accomplished this goal. We are in the process of developing a number of proposals which will be submitted for IsoDAR over the next year.
