PAC2013 - List of Authors (Schenkel, T.)

Paper

Title

Page

Commissioning and Initial Experiments on NDCX-II

108

T. Schenkel, W.G. Greenway, S.M. Lidia, K. Murphy, W.L. Waldron, C.D. Weis
LBNL, Berkeley, California, USA

Funding: This work is supported by the Director, Office of Science, Office of Fusion Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Neutralized Drift Compression Experiment (NDCX-II) is a new induction accelerator facility designed to facilitate user experiments in high energy density laboratory physics, intense beam physics, and materials processing and testing with intense, pulsed ion beams. The facility has completed the initial commissioning phase of its injector, 27-cell solenoid transport lattice, induction accelerator modules and non-neutral pulse compression section. Space-charge-dominated Li⁺ beams carrying 20-50 nC have been generated from the 133 kV pulsed, ~1.0 microsecond (FWHM), 65-mA injector, and compressed to 20-30 ns with 0.75-1.3 A peak currents and amplification factors of 10-20. We report results of non- neutral beam compression and transport studies to generate variable ion beam fluences on to solid targets. We also report on studies of dose rate effects in pulsed ion implantation and on the recombination dynamics of radiation induced defects in semiconductors using the NDCX-II Li⁺ beam.

WEOBB2

Development of a Time-tagged Neutron Source for Imaging with Enhanced Spatial Resolution

T. Schenkel, Q. Ji, B.A. Ludewigt, W.L. Waldron
LBNL, Berkeley, California, USA

Funding: Work supported by DOE, Office of Nonproliferation & Verification R&D and performed under the auspices of the U. S. DOE by LBNL under contract No. DE-AC02-05CH11231.
Associate particle imaging (API) is an active interrogation method for neutron based imaging of materials. Energetic alpha particles are emitted in kinematic correlation with neutrons in DT fusion reactions, forming a virtual neutron beam. When alphas are detected in a position sensitive detector and their arrival time is also recorded then time tagged neutrons can be used for 3D imaging e. g. of concealed objects in a transmission geometry or through detection of a prompt gamma ray. The imaging resolution in API systems is often limited by the area from which neutron originate. This area is determined by the spot size of a mixed D⁺ and T⁺ ion beam. We have adapted microwave driven ion sources (permanent magnets, 2.45 GHz) for the efficient production of hydrogen ions (all isotopes) with high current density (50 to 100 mA/cm²) and high fractions of atomic ions [1]. The high current density allows us to extract ions with small apertures and form beam spots on the neutron production target of less than 1 mm in diameter. In our presentation we will describe the API principle and report our results on the development of an API system with high spatial resolution.
[1] Q. Ji, AIP Conf. Proc. Vol 1336, 528-532 (2011).

Slides WEOBB2 [1.262 MB]

Paper	Title	Page
MOPAC19	Commissioning and Initial Experiments on NDCX-II	108
	T. Schenkel, W.G. Greenway, S.M. Lidia, K. Murphy, W.L. Waldron, C.D. Weis LBNL, Berkeley, California, USA
	Funding: This work is supported by the Director, Office of Science, Office of Fusion Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The Neutralized Drift Compression Experiment (NDCX-II) is a new induction accelerator facility designed to facilitate user experiments in high energy density laboratory physics, intense beam physics, and materials processing and testing with intense, pulsed ion beams. The facility has completed the initial commissioning phase of its injector, 27-cell solenoid transport lattice, induction accelerator modules and non-neutral pulse compression section. Space-charge-dominated Li⁺ beams carrying 20-50 nC have been generated from the 133 kV pulsed, ~1.0 microsecond (FWHM), 65-mA injector, and compressed to 20-30 ns with 0.75-1.3 A peak currents and amplification factors of 10-20. We report results of non- neutral beam compression and transport studies to generate variable ion beam fluences on to solid targets. We also report on studies of dose rate effects in pulsed ion implantation and on the recombination dynamics of radiation induced defects in semiconductors using the NDCX-II Li⁺ beam.

WEOBB2	Development of a Time-tagged Neutron Source for Imaging with Enhanced Spatial Resolution
	T. Schenkel, Q. Ji, B.A. Ludewigt, W.L. Waldron LBNL, Berkeley, California, USA
	Funding: Work supported by DOE, Office of Nonproliferation & Verification R&D and performed under the auspices of the U. S. DOE by LBNL under contract No. DE-AC02-05CH11231. Associate particle imaging (API) is an active interrogation method for neutron based imaging of materials. Energetic alpha particles are emitted in kinematic correlation with neutrons in DT fusion reactions, forming a virtual neutron beam. When alphas are detected in a position sensitive detector and their arrival time is also recorded then time tagged neutrons can be used for 3D imaging e. g. of concealed objects in a transmission geometry or through detection of a prompt gamma ray. The imaging resolution in API systems is often limited by the area from which neutron originate. This area is determined by the spot size of a mixed D⁺ and T⁺ ion beam. We have adapted microwave driven ion sources (permanent magnets, 2.45 GHz) for the efficient production of hydrogen ions (all isotopes) with high current density (50 to 100 mA/cm²) and high fractions of atomic ions [1]. The high current density allows us to extract ions with small apertures and form beam spots on the neutron production target of less than 1 mm in diameter. In our presentation we will describe the API principle and report our results on the development of an API system with high spatial resolution. [1] Q. Ji, AIP Conf. Proc. Vol 1336, 528-532 (2011).
	Slides WEOBB2 [1.262 MB]