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Title: Microwave Ion Source and Beam Injection for an Accelerator-drivenNeutron Source

Abstract

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 focus 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.

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE
OSTI Identifier:
926595
Report Number(s):
LBNL-62514
R&D Project: Z2IS29; BnR: 600301010
DOE Contract Number:
DE-AC02-05CH11231
Resource Type:
Conference
Resource Relation:
Conference: 22nd Partical Accelerator Conference 2007.PAC'07, Albuquerque, NM, June 25th - 29th, 2007
Country of Publication:
United States
Language:
English
Subject:
70; Ion source neutral beam injection neutron generator Low energybeam transport beam diagnostic

Citation Formats

Vainionpaa, J.H., Gough, R., Hoff, M., Kwan, J.W., Ludewigt,B.A., Regis, M.J., Wallig, J.G., and Wells, R.. Microwave Ion Source and Beam Injection for an Accelerator-drivenNeutron 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.. Microwave Ion Source and Beam Injection for an Accelerator-drivenNeutron 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.. Thu . "Microwave Ion Source and Beam Injection for an Accelerator-drivenNeutron Source". United States. doi:. https://www.osti.gov/servlets/purl/926595.
@article{osti_926595,
title = {Microwave Ion Source and Beam Injection for an Accelerator-drivenNeutron 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 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 focus 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.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}

Conference:
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  • 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 LEBTmore » 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.« less
  • A large area surface source of Lithium plasma for use as an ion source in the PBFA-2 ion beam diode is described. BOLVAPS produces a 1--2 mm thick layer of Li vapor with a density approaching 1 {times} 10{sup 17} cm{sup {minus}3} by rapid ohmic heating of a thin film laminate, one layer of which contains Li. The principal design issues of the vapor source being built for use on the PBFA-2 accelerator are described. LIBORS uses 670.8 nm laser light to efficiently ionize the Li vapor. The results of small-scale Physics tests and full-scale component development are summarized. 13more » refs., 6 figs.« less
  • The Mevva (metal vapor vacuum arc) ion source provides high current beams of multiply-charged metal ions suitable for use in heavy ion synchrotrons as well as for metallurgical ion implantation. Pulsed beam currents of up to several amperes can be produced at ion energies of up to several hundred keV. Operation has been demonstrate for 48 metallic ion species: Li, C, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, Sr, Y, Zr, Nb, Mo, Pd, Ag, Cd, In, Sn, Ba, La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, Er, Yb, Hf, Ta, W,more » Ir, Pt, Au, Pb, Bi, Th and U. When the source is operated optimally the rms fractional beam noise can be as low as 7% of the mean beam current; and when properly triggered the source operates reliably and reproducibly for many tens of thousands of pulses without failure. In this paper we review the source performance referred specifically to its use for synchrotron injection. 15 refs., 3 figs.« less
  • Beam characteristics of a microwave ion source for implantation were studied with an apparatus that can evaluate the degree of matching between the ion source and mass-separator optics. The principal cause that limits the beam transmission of mass separator optics was clarified and an approach was taken to eliminate it. The emittance for the length depends on the plasma density distribution along the slit, which was found to be closely related to the vapor inlet system of the plasma chamber. In order to make the plasma density distribution uniform, several vapor inlets were arranged in a line along the slit.more » This resulted in a lower emittance.« less
  • At the Lawrence Berkeley National Laboratory (LBNL) a diagnostic neutral beam injection system for measuring plasma parameters, flow velocity, and local magnetic field is being developed. The systems is designed to have a 90 % proton fraction and small divergence with beam current at 5-6 A and a pulse length of {approx}1 s occurring once every 1-2 min. The ion source needs to generate uniform plasma over a large (8 cm x 5 cm) extraction area. For this application, we have compared RF driven multicusp ion sources operating with either an external or an internal antenna in similar ion sourcemore » geometry. The ion beam will be made of an array of six sheet-shaped beamlets. The design is optimized using computer simulation programs.« less