Recent Paper

The Desktop Muon Detector: A simple, physics-motivated machine- and electronics-shop project for university students

This paper describes an undergraduate-level physics project that incorporates various aspects of machine- and electronics-shop technical development. The desktop muon detector is a self-contained apparatus that employs plastic scintillator as a detection medium and a silicon photomultiplier for light collection. These detectors can be used in conjunction with the provided software to make interesting physics measurements. The total cost of each counter is approximately \$100.

A new sterile neutrino proposal

Decisive disappearance search at high Δm2 with monoenergetic muon neutrinos

KPipe” is a proposed experiment which will study muon neutrino disappearance for a sensitive test of the Δm2∼1  eV2 anomalies, possibly indicative of one or more sterile neutrinos. The experiment is to be located at the J-PARC Materials and Life Science Experimental Facility’s spallation neutron source, which represents the world’s most intense source of charged kaon decay-at-rest monoenergetic (236 MeV) muon neutrinos. The detector vessel, designed to measure the charged-current interactions of these neutrinos, will be 3 m in diameter and 120 m long, extending radially at a distance of 32 to 152 m from the source. This design allows a sensitive search for νμ disappearance associated with currently favored light sterile neutrino models and features the ability to reconstruct the neutrino oscillation wave within a single, extended detector. The required detector design, technology, and costs are modest. The KPipe measurements will be robust since they depend on a known energy neutrino source with low expected backgrounds. Further, since the measurements rely only on the measured rate of detected events as a function of distance, with no required knowledge of the initial flux and neutrino interaction cross section, the results will be largely free of systematic errors. The experimental sensitivity to oscillations, based on a shape-only analysis of the L/E distribution, will extend an order of magnitude beyond present experimental limits in the relevant high-Δm2 parameter space.

Thinking about RFQ injection into a cyclotron

Preliminary design of a RFQ direct injection scheme for the IsoDAR high intensity H+22+ cyclotron

IsoDAR (Isotope Decay-At-Rest) is a novel experiment designed to measure neutrino oscillations through ν̄ eν̄e disappearance, thus providing a definitive search for sterile neutrinos. In order to generate the necessary anti-neutrino flux, a high intensity primary protonbeam is needed. In IsoDAR, H+22+ is accelerated and is stripped into protons just before the target, to overcome space charge issues at injection. As part of the design, we have refined an old proposal to use a RFQ to axially inject bunched H+22+ ions into the driver cyclotron.

This method has several advantages over a classical low energybeam transport (LEBT) design: (1) The bunching efficiency is higher than for the previously considered two-gap buncher and thus the overall injection efficiency is higher. This relaxes the constraints on the H+22+ current required from the ion source. (2) The overall length of the LEBT can be reduced. (3) The RFQ can also accelerate the ions. This enables the ion source platform high voltage to be reduced from 70 kV to 15 kV, making underground installation easier. We are presenting the preliminary RFQ design parameters and first beam dynamics simulations from the ion source to the spiral inflector entrance.

A new multi-cusp ion source for IsoDAR

A high intensity H+2H2+ multicusp ion source for the isotope decay-at-rest experiment, IsoDAR

The Isotope Decay-At-Rest (IsoDAR) experimental program aims to decisively test the sterile neutrino hypothesis. In essence, it is a novel cyclotron based neutrino factory that will improve the frontiers in both high-intensity cyclotrons and electron flavor anti-neutrino sources. By using a source in which the usual H− ions are replaced with the more tightly bound H+2H2+ ions, we can negate the effects of Lorentz stripping in a cyclotron, reduce the overall perveance due to the space-charge effect, and deliver twice the number of protons per nuclei on target. To produce the H+2H2+ , we are currently developing a dedicated multicusp ion source, MIST-1 (generation-1 Multicusp Ion Source Technologies at MIT), and a low-energy beam transport system for the IsoDAR cyclotron. This will increase the overall H+2H2+ current leading up to the cyclotron and improve the emittance of the beam injected into the cyclotron.