Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-18T08:45:02.122Z Has data issue: false hasContentIssue false

Transport of intense beams with current-dependent initial conditions in linearly tapered solenoid channels

Published online by Cambridge University Press:  21 October 2019

J. R. Harris*
Affiliation:
Air Force Research Laboratory, Albuquerque, NM87117, USA
*
Author for correspondence: J. R. Harris, Kirtland Air Force Base, 3550 Aberdeen Ave. SE, Albuquerque, NM87117, USA.

Abstract

In electron beams where space charge plays an important role in the beam transport, the beams’ transverse and longitudinal properties will become coupled. One example of this is the transverse–longitudinal correlation produced in a current-modulated beam generated in a DC electron gun, formed through the competition between the time-dependent radial space charge force and the time-independent radial focusing force. This correlation will cause both the slice radius and divergence of the beam extracted from the gun to depend on the slice current. Here we consider the transport of such a beam in a linearly tapered solenoid focusing channel. Transport performance was generally improved with longer taper lengths, minimal initial correlation between slice divergence and slice current, and moderate degrees of initial correlation between initial slice radius and slice current. Performance was also generally improved with lower slice emittances, although surprisingly transport was improved by slightly increasing the assumed slice emittance in certain limited circumstances.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2019

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bernal, S, Kishek, RA, Reiser, M and Haber, I (1999 a) Observations and simulations of particle-density oscillations in an apertured, space-charge dominated electron beam. Proceedings of the 1999 Particle Accelerator Conference (Cat. No. 99CH36366), 1749–1751. New York: IEEE.Google Scholar
Bernal, S, Kishek, RA, Reiser, M and Haber, I (1999 b) Observations and simulations of transverse density waves in a collimated space-charge dominated electron beam. Physical Review Letters 82, 4002.CrossRefGoogle Scholar
Bernal, S, Quinn, B, Reiser, M and O'Shea, PG (2002) Edge imaging in intense beams. Physical Review Special Topics – Accelerators and Beams 5, 064202.CrossRefGoogle Scholar
Bernal, S, Li, H, Kishek, RA, Quinn, B, Walter, M, Reiser, M, O'Shea, PG and Allen, CK (2006) RMS envelope matching of electron beams from “zero” current to extreme space charge in a fixed lattice of short magnets. Physical Review Special Topics – Accelerators and Beams 9, 064202.CrossRefGoogle Scholar
Bernal, S, Beaudoin, B, Haber, I, Koeth, T, Mo, Y, Montgomery, E, Rezaei, KP, Ruisard, K, Stern, W, Sutter, D, Zang, H and Kishek, RA (2016) Nonlinear dynamics with space-charge in a small electron recirculator. AIP Conference Proceedings 1777, 100003.CrossRefGoogle Scholar
Biswas, B (2013) A model of field and spherical aberration in soft/hard edge solenoid magnets. Review of Scientific Instruments 84, 103301.CrossRefGoogle Scholar
Brinkmann, R, Derbenev, Y and Flottmann, K (2001) A low emittance, flat-beam electron source for linear colliders. Physical Review Special Topics – Accelerators and Beams 4, 053501.CrossRefGoogle Scholar
Efthymiopoulos, L, Gilardoni, S, Hansen, OM and Prior, G (2013) A simplified magnetic field tapering and target optimisation for the neutrino factory capture system. Proceedings of the 2013 International Particle Accelerator Conference, 1370–1372. Available at: https://accelconf.web.cern.ch/accelconf/IPAC2013/papers/tupfi018.pdfGoogle Scholar
Ein-Gal, M (2009) Adjustable aperture collimator. U.S. Patent 7,489,764, February 10.Google Scholar
Floettmann, K (2004) Positron source options for linear colliders. Proceedings of the 2004 European Particle Accelerator Conference, 69–73. Available at: https://accelconf.web.cern.ch/accelconf/e04/PAPERS/TUZACH01.PDFGoogle Scholar
Harris, JR and Lewellen, JW (2010 a) Transmission of intense electron beams through apertures. Physics of Plasmas 17, 043101.CrossRefGoogle Scholar
Harris, JR and Lewellen, JW (2010 b) Suppression of current fluctuations in an intense electron beam. Journal of Applied Physics 108, 083301.CrossRefGoogle Scholar
Harris, JR, Feldman, RB and O'Shea, PG (2007 a) Transverse-longitudinal coupling in an intense electron beam. Proceedings of the 2007 Particle Accelerator Conference, 3597–3599. New York: IEEE.CrossRefGoogle Scholar
Harris, JR, Neumann, JG, Tian, K and O'Shea, PG (2007 b) Longitudinal density modulation and energy conversion in intense beams. Physical Review E 76, 026402.CrossRefGoogle ScholarPubMed
Harris, JR, Lewellen, JW and Poole, BR (2012) Transverse-longitudinal correlations in electron guns. Journal of Applied Physics 112, 023304.CrossRefGoogle Scholar
Harris, JR, Lewellen, JW and Poole, BR (2013) Transport of electron beams with initial transverse-longitudinal correlation. Journal of Applied Physics 114, 063304.CrossRefGoogle Scholar
Harris, JR, Jensen, KL, Maestas, S, Tang, W and Shiffler, DA (2017 a) Practical considerations in the modeling of field emitter arrays with line charge distributions. Journal of Applied Physics 121, 203303.CrossRefGoogle Scholar
Harris, JR, Poole, BR and Lewellen, JW (2017 b) Solenoid transport of beams with current-dependent initial conditions. Journal of Applied Physics 122, 093302.CrossRefGoogle Scholar
Hoff, BW, French, D.M, Simon, DS, Lepell, PD, Montoya, T and Heidger, SL (2017) High current nonlinear transmission line based electron beam driver. Physical Review Accelerators and Beams 20, 100401.CrossRefGoogle Scholar
James, MB, Donahue, RJ, Miller, RH and Nelson, WR (1991) A new target design and capture strategy for high-yield positron production in electron linear colliders. Nuclear Instruments and Methods A 307, 207212.CrossRefGoogle Scholar
Leupold, HA (1987) Leakage-free, linearly varying axial permanent magnet field source. U.S. Patent 4,701,737, October 20.Google Scholar
Leupold, HA (1993) Magnetic field sources for producing high-intensity variable fields. U.S. Patent 5,216,400, June 1.Google Scholar
Leupold, HA, Tilak, AS and Potenziani, E (1992) Tapered fields in cylindrical and spherical spaces. IEEE Transactions on Magnetics 28, 30453047.CrossRefGoogle Scholar
Li, Y and Lewellen, JW (2008) Generating a quasiellipsoidal electron beam by 3D laser-pulse shaping. Physical Review Letters 100, 074801.CrossRefGoogle ScholarPubMed
Limborg-Deprey, C and Bolton, PR (2006) Optimum electron distributions for space charge dominated beams in photoinjectors. Nuclear Instruments and Methods in Physics A 557, 106116.CrossRefGoogle Scholar
Lund, SM (2015) Nonlinear optics of solenoid magnets. Proceedings of the 2015 International Particle Accelerator Conference, 4048–4050. Available at: http://accelconf.web.cern.ch/AccelConf/IPAC2015/papers/thpf139.pdf.Google Scholar
McDonald, KT, Sayed, HK, Berg, JS, Kirk, HG and Palmer, RB (2014) Optimized capture-solenoid field for a muon accelerator font end. Available at: http://cosmology.princeton.edu/mumu/target/Sayed/140129/SolTaper-140129_k9.pdfGoogle Scholar
Mohsen, O, Gonin, I, Kephart, R, Khabiboulline, T, Piot, P, Solyak, N, Thangaraj, JC and Yakovlev, V (2018) Initial beam dynamics simulations of a high-average-current field-emission electron source in a superconducting radiofrequency gun. Nuclear Instruments and Methods A 909, 456459.CrossRefGoogle Scholar
Peterson, RE (2011) Shielding Requirements for an Energy-Recovery Linac Free-Electron Laser. MS Thesis, Naval Postgraduate School.Google Scholar
Pierce, JR (1940) Rectilinear electron flow in beams. Journal of Applied Physics 11, 548554.CrossRefGoogle Scholar
Poole, BR, Blackfield, DT, Chen, Y-J, Harris, JR and O'Shea, PG (2009) Space charge waves in mismatched beams. Proceedings of the 2009 Particle Accelerator Conference, 3272–3274. Available at: https://accelconf.web.cern.ch/AccelConf/PAC2009/papers/th5pfp035.pdfGoogle Scholar
Poursaleh, A (2013) Design and simulation of high power RF modulated triode electron gun. Life Science Journal 10, 26852689.Google Scholar
Reiser, M (2008) Theory and Design of Charged Particle Beams. New York: Wiley.CrossRefGoogle Scholar
Sayed, HK and Berg, JS (2014) Optimized capture section for a muon accelerator front end. Physical Review Special Topics – Accelerators and Beams 17, 070102.CrossRefGoogle Scholar
Spangenberg, KR (1948) Vacuum Tubes. McGraw-Hill: New York.Google Scholar
Stancari, G, Valishev, A, Annala, G, Kuznetsov, G, Shiltsev, V, Still, DA and Vorobiev, LG. (2011) Collimation with hollow electron beams. Physical Review Letters 107, 084802.CrossRefGoogle ScholarPubMed
Umstattd, RJ and Luginsland, JW (2001) Two-dimensional space-charge-limited emission: beam-edge characteristics and applications. Physical Review Letters 87, 145002.CrossRefGoogle ScholarPubMed