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Title: CANCELLED Microwave Ion Source and Beam Injection for anAccelerator-Driven Neut ron Source

Abstract

An over-dense microwave driven ion source capable of producing deuterium (or hydrogen) beams at 100-200 mA/cm{sup 2} and with atomic fraction > 90% was designed and tested with an electrostatic low energy beam transport section (LEBT). This ion source was incorporated into the design of an Accelerator Driven Neutron Source (ADNS). The other key components in the ADNS include a 6 MeV RFQ accelerator, a beam bending and scanning system, and a deuterium gas target. In this design a 40 mA D{sup +} beam is produced from a 6 mm diameter aperture using a 60 kV extraction voltage. The LEBT section consists of 5 electrodes arranged to form 2 Einzel lenses that focus the beam into the RFQ entrance. To create the ECR condition, 2 induction coils are used to create {approx} 875 Gauss on axis inside the source chamber. To prevent HV breakdown in the LEBT a magnetic field clamp is necessary to minimize the field in this region. Matching of the microwave power from the waveguide to the plasma is done by an autotuner. They observed significant improvement of the beam quality after installing a boron nitride liner inside the ion source. The measured emittance data are comparedmore » with PBGUNS simulations.« less

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE. Administrator for National Nuclear Security AdminNonproliferation and National Security Program Direction
OSTI Identifier:
932684
Report Number(s):
LBNL-62514-Ext.-Abs.
R&D Project: Z2IS10 AND Z2IS14; TRN: US0803732
DOE Contract Number:
DE-AC02-05CH11231
Resource Type:
Conference
Resource Relation:
Conference: Proceedings of the PAC07, Albuquerque, NM,06/25-29/2007
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ACCELERATORS; APERTURES; BEAM INJECTION; BEAM TRANSPORT; BENDING; BORON NITRIDES; BREAKDOWN; DESIGN; DEUTERIUM; ELECTRODES; ELECTROSTATICS; HYDROGEN; INDUCTION; ION SOURCES; LENSES; LINERS; MAGNETIC FIELDS; NEUTRON SOURCES; WAVEGUIDES; _Ion Source External RF-antenna Planar inductive source Plasmasource

Citation Formats

Vainionpaa, J.H., Gough, R., Hoff, M., Kwan, J.W., Ludewigt,B.A., Regis, M.J., Wallig, J.G., and Wells, R.. CANCELLED Microwave Ion Source and Beam Injection for anAccelerator-Driven Neut ron Source. United States: N. p., 2007. Web.
Vainionpaa, J.H., Gough, R., Hoff, M., Kwan, J.W., Ludewigt,B.A., Regis, M.J., Wallig, J.G., & Wells, R.. CANCELLED Microwave Ion Source and Beam Injection for anAccelerator-Driven Neut ron Source. United States.
Vainionpaa, J.H., Gough, R., Hoff, M., Kwan, J.W., Ludewigt,B.A., Regis, M.J., Wallig, J.G., and Wells, R.. Tue . "CANCELLED Microwave Ion Source and Beam Injection for anAccelerator-Driven Neut ron Source". United States. doi:. https://www.osti.gov/servlets/purl/932684.
@article{osti_932684,
title = {CANCELLED Microwave Ion Source and Beam Injection for anAccelerator-Driven Neut ron Source},
author = {Vainionpaa, J.H. and Gough, R. and Hoff, M. and Kwan, J.W. and Ludewigt,B.A. and Regis, M.J. and Wallig, J.G. and Wells, R.},
abstractNote = {An over-dense microwave driven ion source capable of producing deuterium (or hydrogen) beams at 100-200 mA/cm{sup 2} and with atomic fraction > 90% was designed and tested with an electrostatic low energy beam transport section (LEBT). This ion source was incorporated into the design of an Accelerator Driven Neutron Source (ADNS). The other key components in the ADNS include a 6 MeV RFQ accelerator, a beam bending and scanning system, and a deuterium gas target. In this design a 40 mA D{sup +} beam is produced from a 6 mm diameter aperture using a 60 kV extraction voltage. The LEBT section consists of 5 electrodes arranged to form 2 Einzel lenses that focus the beam into the RFQ entrance. To create the ECR condition, 2 induction coils are used to create {approx} 875 Gauss on axis inside the source chamber. To prevent HV breakdown in the LEBT a magnetic field clamp is necessary to minimize the field in this region. Matching of the microwave power from the waveguide to the plasma is done by an autotuner. They observed significant improvement of the beam quality after installing a boron nitride liner inside the ion source. The measured emittance data are compared with PBGUNS simulations.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Feb 27 00:00:00 EST 2007},
month = {Tue Feb 27 00:00:00 EST 2007}
}

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  • An over-dense microwave driven ion source capable ofproducing deuterium (or hydrogen) beams at 100-200 mA/cm2 and with atomicfraction>90 percent was designed and tested with an electrostaticlow energy beam transport section (LEBT). This ion source wasincorporatedinto the design of an Accelerator Driven Neutron Source(ADNS). The other key components in the ADNS include a 6 MeV RFQaccelerator, a beam bending and scanning system, and a deuterium gastarget. In this design a 40 mA D+ beam is produced from a 6 mm diameteraperture using a 60 kV extraction voltage. The LEBT section consists of 5electrodes arranged to form 2 Einzel lenses that focusmore » the beam into theRFQ entrance. To create the ECR condition, 2 induction coils are used tocreate ~; 875 Gauss on axis inside the source chamber. To prevent HVbreakdown in the LEBT a magnetic field clamp is necessary to minimize thefield in this region. Matching of the microwave power from the waveguideto the plasma is done by an autotuner. We observed significantimprovement of the beam quality after installing a boron nitride linerinside the ion source. The measured emittance data are compared withPBGUNS simulations.« less
  • An RF driven H[sup [minus]] source has been developed at LBL for use in the Superconducting Super Collider (SSC). To date, an H[sup [minus]] current of [approx]40 mA can be obtained from a 5.6-cm-diam aperture with the source operated at a pressure of about 12 m Torr and 50 kW of RF power. In order to match the accelerated H[sup [minus]] beam into the SSC RFQ, a low-energy H[sup [minus]] injection system has been designed. This injector produces an outgoing H[sup [minus]] beam free of electron contamination, with small radius, large convergent angle and small projectional emittance.
  • An RF driven H{sup {minus}} source has been developed at LBL for use in the Superconducting Super Collider (SSC). To date, an H{sup {minus}} current of {approx}40 mA can be obtained from a 5.6-cm-diam aperture with the source operated at a pressure of about 12 m Torr and 50 kW of RF power. In order to match the accelerated H{sup {minus}} beam into the SSC RFQ, a low-energy H{sup {minus}} injection system has been designed. This injector produces an outgoing H{sup {minus}} beam free of electron contamination, with small radius, large convergent angle and small projectional emittance.
  • A tandem microwave-driven plasma source for the production of H{sup {minus}} ions has been developed and tested. The source has a microwave-driven primary chamber with a thermionic cathode-driven secondary plasma. This source was used to experimentally verify certain aspects of a theoretical model of H{sup {minus}} production by Hiskes. A general agreement with the theory was found for the dependence of produced H{sup {minus}} current with the plasma electron temperature. In addition, it appears that a surface production mechanism on the BaO-impregnated cathode enhanced the H{sup {minus}} current production. Experimental results are given and compared to present theoretical understanding.
  • Circular accelerators used for positron emission tomography (PET, i.e. accelerator used for make radio isotopes) need several mA of CW H- ion beam for their routine operation. Other facilities, like Space Radio-Environment Simulate Assembly (SPRESA), require less than 10 mA pulsed mode H{sup −} beam. Caesium free negative hydrogen ion source is a good choice for those facilities because of its compact structure, easy operation and low cost. Up to now, there is no H{sup −} source able to produce very intense H{sup −} beams with important variation of the duty factor{sup [1]}. Recently, a new version of 2.45 GHz microwave H{supmore » −} ion source was designed at PKU, based on lessons learnt from the previous one. This non cesiated source is very compact thanks to its permanent magnet configuration. Special attention was paid on the design of the discharge chamber structure, electron dumping and extraction system. Source test to produce H{sup −} ion beams in pulsed and CW mode was carried out on PKU ion source test bench. In CW mode, a 10.8 mA/30keV H{sup −} beam with rms emittance about 0.16 π·mm·mrad has been obtained with only 500 W rf power. The power efficiency reaches 21 mA/kW. In pulsed mode with duty factor of 10% (100Hz/1ms), this compact source can easily deliver 20 mA H{sup −} ion beam at 35 keV with rms emittance about 0.2 π·mm·mrad when RF power is set at 2.2 kW (peak power). Several hour successive running operation in both modes and totaling more than 200 hours proves its high quality. The outside dimension of this new H{sup −} source body is ϕ116 mm × 124 mm, and the entire H{sup −} source infrastructure, including rf matching section, plasma chamber and extraction system, is ϕ310 × 180 mm. The high voltage region is limited with in a ϕ310 mm × 230 mm diagram. Details are given in this paper.« less