Beam injector and transport calculations for ITS

Hughes, T.P.; Moir, D.C.; Allison, P.

doi:10.1109/pac.1995.505175

Cited by 14 publications

(12 citation statements)

References 1 publication

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“…The predicted scaling for À m was confirmed in earlier experiments [3], so we used this scaling to design a tune with magnetic field strong enough to suppress the BBU to an amplitude <10% of beam radius. Figure 2 shows the beam envelope calculated by our envelope code XTR [5] for one of our magnetic field tunes, with the saturated BBU amplitude predicted by this theory overplotted. Calculations of saturated growth for this plot used the maximum measured transverse impedances at the major BBU frequencies bands [13,14] near 150, 250, and 600 MHz.…”

Section: A Suppression Of High-frequency Motionmentioning

confidence: 99%

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Suppressing beam-centroid motion in a long-pulse linear induction accelerator

Ekdahl

Abeyta

Archuleta

et al. 2011

Phys. Rev. ST Accel. Beams

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The second axis of the dual-axis radiography of hydrodynamic testing (DARHT) facility produces up to four radiographs within an interval of 1:6 s. It does this by slicing four micropulses out of a 2-s long electron beam pulse and focusing them onto a bremsstrahlung converter target. The 1.8-kA beam pulse is created by a dispenser cathode diode and accelerated to more than 16 MeV by the unique DARHT Axis-II linear induction accelerator (LIA). Beam motion in the accelerator would be a problem for multipulse flash radiography. High-frequency motion, such as from beam-breakup (BBU) instability, would blur the individual spots. Low-frequency motion, such as produced by pulsed-power variation, would produce spot-to-spot differences. In this article, we describe these sources of beam motion, and the measures we have taken to minimize it. Using the methods discussed, we have reduced beam motion at the accelerator exit to less than 2% of the beam envelope radius for the high-frequency BBU, and less than 1=3 of the envelope radius for the low-frequency sweep.

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Section: A Suppression Of High-frequency Motionmentioning

confidence: 99%

“…The beam simulation codes used to clarify beam physics and design the solenoidal focusing are described in Refs. [5][6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Suppressing beam-centroid motion in a long-pulse linear induction accelerator

Ekdahl

Abeyta

Archuleta

et al. 2011

Phys. Rev. ST Accel. Beams

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“…The two most frequently used are XTR [6,7] and LAMDA [8]. In both of these codes the radius of a uniform density beam is calculated from an envelope equation [9,10].…”

Section: A Envelope Codesmentioning

confidence: 99%

Emittance growth in linear induction accelerators

Ekdahl¹,

McCuistian²,

Schulze³

et al. 2014

2014 IEEE 41st International Conference on Plasma Sciences (ICOPS) Held With 2014 IEEE International Conference on High-Power P

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The Dual-Axis Radiographic Hydrotest (DARHT) facility uses bremsstrahlung radiation source spots produced by the focused electron beams from two linear induction accelerators (LIAs) to radiograph large hydrodynamic experiments driven by high explosives. Radiographic resolution is determined by the size of the source spot, and beam emittance is the ultimate limitation to spot size. On the DARHT Axis-II LIA we measure an emittance higher than predicted by theoretical simulations, and even though this axis produces submillimeter source spots, we are exploring ways to improve the emittance. Some of the possible causes for the discrepancy have been investigated using particle-incell (PIC) codes, although most of these are discounted based on beam measurements. The most likely source of emittance growth is a mismatch of the beam to the magnetic transport, which can cause beam halo.

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“…1) was designed using two beam dynamics codes [4]. First, the TRAK electron-gun design code [5] was used to establish initial conditions at the anode (initial radius, divergence, and emittance) for the XTR envelope code [6] at the operating A-K potential of the diode. Then the tune was developed for the energy flattop of the beam using the accelerating voltages expected to be applied to the gaps.…”

Section: Acceleratormentioning

confidence: 99%

Initial electron-beam results from the DARHT-II linear induction accelerator

Ekdahl

Abeyta

Bender

et al. 2005

IEEE Trans. Plasma Sci.

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The DARHT-II linear-induction accelerator has been successfully operated at 1.2-1.3 kA and 12.5-12.7 MeV to demonstrate the production and acceleration of an electron beam. Beam pulse lengths for these experiments were varied from 0.5 s to 1.2 s full-width half-maximum. A low-frequency inductance-capacitance (LC ) oscillation of diode voltage and current resulted in an oscillation of the beam position through interaction with an accidental (static) magnetic dipole in the diode region. There was no growth in the amplitude of this oscillation after propagating more than 44 m through the accelerator, and there was no loss of beam current that could be measured. The results of these initial experiments are presented in this paper.

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Beam injector and transport calculations for ITS

Cited by 14 publications

References 1 publication

Suppressing beam-centroid motion in a long-pulse linear induction accelerator

Suppressing beam-centroid motion in a long-pulse linear induction accelerator

Emittance growth in linear induction accelerators

Initial electron-beam results from the DARHT-II linear induction accelerator

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