56 research outputs found
The front-end of IsoDAR
No full textThe Isotope Decay-At-Rest (IsoDAR) experiment is a cyclotron based neutrino oscillation exper- iment that is capable of decisively searching for low-mass sterile neutrinos. This paper outlines two new approaches that the IsoDAR collaboration are pursuing in order to increase the amount of H + 2 captured in the cyclotron through innovations in the design of the front-end. A new dedicated multicusp ion source (MIST-1) is currently being commissioned and tested at the Plasma Science and Fusion Center (PSFC) at MIT. Based on previous results from this type of ion source, we ex- pect to be able to achieve an H+₂ current density that will be sufficient for the IsoDAR experiment. We also discuss the results of a new investigation into using a radio frequency quadrupole (RFQ) as a high-efficiency buncher to improve the injection efficiency into the cyclotron.National Science Foundation (U.S.) (Grant 1505858)National Science Foundation (U.S.) (Grant 1626069
AN RFQ DIRECT INJECTION SCHEME FOR THE ISODAR HIGH INTENSITY H+₂ CYCLOTRON
No full textIsoDAR is a novel experiment designed to measure neutrino oscillations through e disappearance, thus providing a definitive search for sterile neutrinos. In order to generate the necessary anti-neutrino flux, a high intensity primary proton beam is needed. In IsoDAR, H+2 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 an RFQ to axially inject bunched H+2 ions into the driver cyclotron. This method has several advantages over a classical low energy beam 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+2 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 30 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.National Science Foundation (U.S.). Division of Physics (NSF-PHY-1148134)MIT Energy Initiative Seed Fund Progra
IsoDAR@Yemilab – A definitive search for exotic neutrinos and other BSM physics
No full textThe IsoDAR neutrino source comprises a novel compact cyclotron capable of delivering 10 mA of 60 MeV protons in cw mode and a high-power neutrino production target. It has obtained preliminary approval to run at the new underground facility Yemilab in South Korea. IsoDAR will produce a very pure, isotropic nuebar source, with peak neutrino energy around 6 MeV and endpoint around 15 MeV. Paired with a kton-scale detector like the planned Liquid Scintillator Counter (LSC) at Yemilab, IsoDAR can measure nuebar disappearance through the inverse beta decay (IBD) channel. We expect about 1.67·106 IBD events, and ~7000 nuebar – electron elastic scatter events in the LSC in five years of running. This paper presents an overview of the IsoDAR experiment to be installed at Yemilab. We briefly introduce the novel cyclotron design that lets us reach this nuebar source intensity, the target, and the layout at Yemilab. We further describe the potential physics reach of IsoDAR@Yemilab. The unique capability of IsoDAR@Yemilab to continuously measure the oscillation probability up to L(m)/E(MeV) ~ 8 allows us to distinguish many different models for light, sterile neutrinos, including wavepacket effects and neutrino decay. Furthermore, we expect a ×5 improvement on existing limits for non-standard interactions (NSI). Finally, IsoDAR@Yemilab is sensitive to new particles produced in the target (such as a light X boson, that decays to nuebar-nue)
The IsoDAR high intensity H2+ transport and injection tests
No full textThis technical report reviews the tests performed at the Best Cyclotron Systems, Inc. facility in regards to developing a cost effective ion source, beam line transport system, and acceleration system capable of high H[subscript 2][superscript +] current output for the IsoDAR (Isotope Decay At Rest) experiment. We begin by outlining the requirements for the IsoDAR experiment then provide overviews of the Versatile Ion Source (VIS), Low Energy Beam Transport (LEBT) system, spiral inflector, and cyclotron. The experimental measurements are then discussed and the results are compared with a thorough set of simulation studies. Of particular importance we note that the VIS proved to be a reliable ion source capable of generating a large amount of H[subscript 2][superscript +] current. The results suggest that with further upgrades, the VIS could potentially be a suitable candidate for IsoDAR. The conclusion outlines the key results from our tests and introduces the forthcoming work this technical report has motivated.National Science Foundation (U.S.) (PHY-1148134)Massachusetts Institute of Technology (Seed Fund)Massachusetts Institute of Technology (Bose Fellowship
Electron emission from insulators upon impact of slow highly charged ions
No full textDie vorliegende Arbeit beschäftigt sich mit der Untersuchung von Elektronen-Emission von Isolator-Targets bei Beschuss mit sehr langsamen, hochgeladenen Ionen.Die Elektronen-Emission von Leitern wurde in den letzten Jahren sehr gründlich untersucht und ein theoretisches Modell (das classical over-the-barrier, COB Modell) zur Beschreibung der potentiellen Emission (hervorgerufen durch die potentielle Energie des Projektils) wurde entwickelt. Dieses Modell hat sehr gute Übereinstimmung mit den experimentellen Ergebnissen gezeigt. Grundlagenforschung auf dem Gebiet der Ion-Oberflächen Wechselwirkung verspricht Anwendungen in verschiedensten Bereichen von Wissenschaft und Technik, zum Beispiel Fusionsforschung und Nano-Strukturierung. Die vorliegende Arbeit soll einen kleinen Teil zu dieser Forschung beitragen, durch verbesserte und teilweise neue Methoden im Bereich der Elektronen-Emission von Isolatoren und entsprechenden Messungen.Während dem Fortschreiten dieser Arbeit wurden im Wesentlichen alle Stufen eines wissenschaftlichen Projektes durchlaufen: Die Planung des Detektor-Setups, das Ausführen von Simulationen um die Funktionalität des Setups zu überprüfen, Aufbau und Test des Setups, das Durchführen von Messungen und zuletzt, das Auswerten und Interpretieren der Daten.Alle Messungen wurden an einer EBIT (Elektronen-Strahl Ionenfalle) mit angeschlossener Abbrems-Beamline durchgeführt. Xenon-Ionen mit Ladungszuständen von 20+ bis 40+ mit kinetische Energien pro Ladungszustand bis hinunter zu praktischThe present thesis describes investigations of electron emission from insulating targets under bombardment with very slow highly charged ions. Electron emission from conductors has been thoroughly investigated in the past years and a theoretical model (the classical over-the-barrier model) for the contribution of potential emission (induced by the projectiles potential energy) has been developed and proven to be reliable. Fundamental research in the field of ion-surface interaction promises applications in various branches of science and technology, e.g. fusion research and nano-structuring. The present thesis shall contribute with improved, sometimes new methods in the field of electron emission from insulators and respective measurements.During the advance of the thesis every stage of a scientific project was implemented: Planning the detector setup, conducting simulations to verify its usability, mounting and testing of the setup, measuring and last, evaluating and interpreting the data.All measurements were conducted utilizing an EBIT (electron beam ion trap) and a deceleration beam line. Xenon-ions with charge states from 20+ to 40+ were used as projectiles with kinetic energies per charge state down to virtuall
A New Family of Cyclotrons for Particle Physics, Medical Physics, and Other Applications
No full textBased on the IsoDAR 60 MeV/amu compact cyclotron design, which introduces several novel ideas for this type of particle accelerator, we describe a new family of high-current cyclotrons with energy from 1 to 60 MeV for use as a tool for particle physics, isotope production, and other uses. The design is modular, with design features upstream of 1 MeV identical for any energy and easily customized equipment downstream to reach the desired energy. The cyclotrons accelerate 5 mA of H2+, which is then extracted and stripped of the binding electron to produce 10 mA of protons, regardless of design energy. Multiple beamlines can be fed from a single cyclotron by partially occluding the beam with extraction foils. Because the accelerators are low-cost and relatively small, they can be installed at local sites. We describe the main design features and novelties alongside an extensive simulation effort. We further describe several applications at 5 MeV (for 18F production for medical imaging), 15 MeV (nue flux measurements by targeting 27Al), and 60 MeV (IsoDAR, a definitive search for sterile neutrinos and non-standard interactions)
IsoDAR@Yemilab—A Definitive Search for Noble Neutrinos and Other BSM Physics †
No full textThe IsoDAR neutrino source comprises a novel compact cyclotron capable of delivering 10 mA of 60 MeV protons in cw mode and a high-power neutrino production target. It has obtained preliminary approval to run at the new underground facility Yemilab in South Korea. IsoDAR will produce a very pure, isotropic ν¯e source, with a peak neutrino energy of around 6 MeV and an endpoint around 15 MeV. Paired with a kton-scale detector like the planned Liquid Scintillator Counter (LSC) at Yemilab, IsoDAR can measure ν¯e disappearance through the inverse beta decay (IBD) channel. We expect about 1.67·106 IBD events and 7000 ν¯e – e− elastic scatter events in the LSC in five years of running, letting us distinguish many different models for noble (aka sterile) neutrinos and significantly improving existing limits for Non-Standard Interactions (NSIs). Finally, IsoDAR@Yemilab is sensitive to new particles produced in the target (such as light X bosons that decay to ν¯eνe). We describe the accelerator developments for IsoDAR that enable us to produce about a mole of neutrinos in five years of running. These include direct injection through a radiofrequency quadrupole, exploiting complex beam dynamics, and applying machine learning in accelerator design and optimization
Design study of a Split-Coaxial RFQ for IsoDAR
No full text© Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). The Isotope Decay-At-Rest experiment (IsoDAR) is a proposed experiment to search for sterile neutrinos by measuring neutrino oscillations. The electron-antineutrino generation requires a high intensity primary proton beam impinging on a beryllium target surrounded by lithium . In IsoDAR, H2+ ions are generated and accelerated to avoid space charge effects in the low energy region, which will be stripped into protons after extraction from a cyclotron. As part of the IsoDAR injection system, an RFQ buncher with 32.8 MHz of operation frequency provides 70 keV acceleration and strong bunching of the H2+ beam. The RFQ will be installed halfway inside the iron yoke of the cyclotron to be very close to the median plane. Because the beam starts diverging after the RFQ in both transverse and longitudinal direction, a re-buncher is employed in the end transition cell to re-focus the beam longitudinally. In this paper, we describe in detail the beam dynamics study and RF analysis of the IsoDAR RFQ for direct injection into a compact cyclotron
Analyzing beam-gas interactions in an H2+ cyclotron beam
No full textFor the Isotope Decay At Rest (IsoDAR) experiment in neutrino physics (searching for sterile neutrinos), we have developed a novel compact isochronous cyclotron with direct injection through an axially embedded RFQ. For IsoDAR to be decisive within five years of running, 10 mA of protons, cw at 80% duty factor are needed on a neutrino production target. To alleviate space charge in the cyclotron driver, we accelerate 5 mA of , to be broken up into 10 mA of protons after extraction from the cyclotron. An open question that we are answering with this paper is whether the beam losses from gas-stripping (the removal of electrons from through the interaction of the beam ions with the residual gas in the accelerator) are going to be a significant challenge. Using a newly added feature to the well-established Object-Oriented Parallel Accelerator Library code, we calculate gas-stripping losses in the IsoDAR cyclotron using realistic beam distributions, magnetic fields, gas composition, and pressure. We show that to maintain losses due to dissociation below 1% over the entire acceleration region, a vacuum of at least 6 ?? 10???7 mbar is required
A new family of high-current cyclotrons for isotope production
No full textWe are developing a high-current cyclotron as a driver for the IsoDAR neutrino experiment. It accelerates 5 mA of H2 + to 60 MeV/amu, after which the electron is removed to produce a 10 mA, 60 MeV proton beam. The enabling innovations that offset space-charge effects occur at injection and in the first few turns, allowing one to construct cyclotrons with energies ranging from below 5 MeV up to 60 MeV/amu, or possibly higher, with the same performance for accelerated ions with Q/A = 0.5 (H2+, D+, He++, …). In this paper, we discuss the possible uses of such cyclotrons for isotope production, including production of long-lived generator parents (68Ga, 44Ti, 82Sr,…), as well as intense fast neutron beams from deuteron breakup for (n,2n) production of isotopes like 225Ac
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