IPAC2015 - List of Authors (Conrad, J.M.)

Paper	Title	Page
TUPWI019	Neutron Shielding Optimization Studies	2282
	A. Bungau, R.J. Barlow University of Huddersfield, Huddersfield, United Kingdom J.R. Alonso, L.M. Bartoszek, J.M. Conrad MIT, Cambridge, Massachusetts, USA M. Shaevitz Columbia University, New York, USA
	The IsoDAR sterile-neutrino search calls for a high neutron flux from a 60 MeV proton beam striking a beryllium target, that flood a sleeve of highly-enriched ⁷Li, the beta-decay of the resulting ⁸Li giving the desired neutrinos for the very-short-baseline experiment. The target is placed very close to an existing large neutrino detector; all such existing or planned detectors are deep underground, in low-background environments. It is necessary to design a shielding enclosure to prevent neutrons from causing unacceptable activation of the environment. GEANT4 is being used to study neutron attenuation, and optimizing the layers of shielding material to minimize thickness. Materials being studied include iron and two new types of concrete developed by Jefferson Laboratory, one very light with shredded plastic aggregate, the other with high quantities of boron. Initial studies indicate that a total shielding thickness of 1.5 meters produces the required attenuation factor, further studies may allow decrease in thickness. Minimizing it will reduce the amount of cavity excavation needed to house the target system in confined underground spaces.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPWI019
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WEPTY048	An RFQ Direct Injection Scheme for the IsoDAR High Intensity H²⁺ Cyclotron	3384
	D. Winklehner, J.R. Alonso, J.M. Conrad MIT, Cambridge, Massachusetts, USA R.W. Hamm R&M Technical Enterprises, Pleasanton, California, USA
	IsoDAR is a novel experiment designed to measure neutrino oscillations through electron-antineutrino 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, H²⁺ 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 H²⁺ 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 H²⁺ 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 will present preliminary RFQ design parameters and first beam dynamics simulations from the ion source to the spiral inflector.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPTY048
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Neutron Shielding Optimization Studies

2282

A. Bungau, R.J. Barlow
University of Huddersfield, Huddersfield, United Kingdom
J.R. Alonso, L.M. Bartoszek, J.M. Conrad
MIT, Cambridge, Massachusetts, USA
M. Shaevitz
Columbia University, New York, USA

The IsoDAR sterile-neutrino search calls for a high neutron flux from a 60 MeV proton beam striking a beryllium target, that flood a sleeve of highly-enriched ⁷Li, the beta-decay of the resulting ⁸Li giving the desired neutrinos for the very-short-baseline experiment. The target is placed very close to an existing large neutrino detector; all such existing or planned detectors are deep underground, in low-background environments. It is necessary to design a shielding enclosure to prevent neutrons from causing unacceptable activation of the environment. GEANT4 is being used to study neutron attenuation, and optimizing the layers of shielding material to minimize thickness. Materials being studied include iron and two new types of concrete developed by Jefferson Laboratory, one very light with shredded plastic aggregate, the other with high quantities of boron. Initial studies indicate that a total shielding thickness of 1.5 meters produces the required attenuation factor, further studies may allow decrease in thickness. Minimizing it will reduce the amount of cavity excavation needed to house the target system in confined underground spaces.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPWI019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPTY048

An RFQ Direct Injection Scheme for the IsoDAR High Intensity H²⁺ Cyclotron

3384

D. Winklehner, J.R. Alonso, J.M. Conrad
MIT, Cambridge, Massachusetts, USA
R.W. Hamm
R&M Technical Enterprises, Pleasanton, California, USA

IsoDAR is a novel experiment designed to measure neutrino oscillations through electron-antineutrino 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, H²⁺ 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 H²⁺ 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 H²⁺ 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 will present preliminary RFQ design parameters and first beam dynamics simulations from the ion source to the spiral inflector.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPTY048

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)