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Physics
Atomic and Molecular Physics, and Optics

New source technologies and their impact on future light sources

Profile image of Bruce CarlstenBruce CarlstenProfile image of W. WhiteW. White

2010, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

https://doi.org/10.1016/J.NIMA.2010.06.100
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Abstract

Emerging technologies are critically evaluated for their feasibility in future light sources. We consider both new technologies for electron beam generation and acceleration suitable for X-ray free-electron lasers (FELs), as well as alternative photon generation technologies including the relatively mature inverse Compton scattering and laser high-harmonic generation. Laser-driven plasma wakefield acceleration is the most advanced of the novel acceleration technologies, and may be suitable to generate electron beams for X-ray FELs in a decade. We provide research recommendations to achieve the needed parameters for driving future light sources, including necessary advances in laser technology.

Key takeaways
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AI

  1. Laser-driven plasma wakefield acceleration (LPA) shows promise for generating 10 GeV electron beams within 5 years.
  2. Emerging technologies like LPA and PWFA can significantly reduce the cost and size of future light sources.
  3. Research recommends advancements in laser technology crucial for developing compact X-ray sources.
  4. Inverse Compton scattering (ICS) offers a cost-effective alternative for producing X-ray sources with ultrashort pulses.
  5. Next-generation light sources need 3-4 orders of magnitude increase in average power for ultrafast laser systems.

FAQs

sparkles

AI

What technological advancements enable compact electron generation in light sources?add

Emerging laser-driven plasma and electron-beam driven plasma technologies can achieve accelerating gradients of 10-100 GV/m, enabling compact and cost-effective electron generation for light sources.

How do plasma-based accelerators improve upon traditional particle accelerators?add

The study reveals that laser plasma accelerators (LPAs) achieve gradients on the order of 100 GV/m, three orders of magnitude higher than conventional accelerators, facilitating compact designs.

What are the expected impacts of PWFA on future X-ray facilities?add

Plasma wakefield acceleration has demonstrated energy gains exceeding 40 GeV, enabling potential integration as a compact 'afterburner' to boost energy in conventional linacs for X-ray facilities.

Which alternative photon generation techniques are discussed alongside FELs?add

The paper reviews inverse Compton scattering (ICS) and laser high-harmonic generation (HHG) as viable alternatives, capable of offering different performance profiles while reducing costs significantly.

What challenges remain for laser-induced acceleration technologies in practical applications?add

Key issues include achieving high average power, laser pulse stability, and refining emittance and energy spread of electron beams to make advanced acceleration methods viable in light sources.

Figures (10)
Fig. 1. Numerical simulation of a large amplitude plasma wave (plasma electron density perturbation) generated by an intense laser pulse, with electrons trapped in the wave being accelerated. In an LPA as shown in Fig. 1, an intense (> 10!® W/cm7?), short (tens of fs) laser pulse is focused into plasma to drive a large amplitude plasma wave [2]. Such laser-driven plasma waves can sustain electric fields in excess of Eo[V/m] = 96(no[cm~3])!/? with a wavelength Ao[um] = 3.3 x 10!°(no[cm~7])~ "7, where
Fig. 1. Numerical simulation of a large amplitude plasma wave (plasma electron density perturbation) generated by an intense laser pulse, with electrons trapped in the wave being accelerated. In an LPA as shown in Fig. 1, an intense (> 10!® W/cm7?), short (tens of fs) laser pulse is focused into plasma to drive a large amplitude plasma wave [2]. Such laser-driven plasma waves can sustain electric fields in excess of Eo[V/m] = 96(no[cm~3])!/? with a wavelength Ao[um] = 3.3 x 10!°(no[cm~7])~ "7, where
Fig. 2. PWFA schematic, indicating plasma oscillations set up by drive electron bunch expelling plasma electrons from the path of the drive bunch. The PWFA is an attractive technology because existing microwave accelerators can efficiently produce high current bunches well suited for driving plasma wakes with fields over 10 GeV/m. The PWFA then acts as a transformer, converting one or more high current, low energy bunches into one or more relatively low current, high energy bunches. This process can be characterized by the ratio of the peak accelerating field to the peak de-accelerating field in the plasma wake, called the transformer ratio [21]. The transformer ratio can be manipulated by tailoring the longitudinal profile of the beams driving and sampling the plasma wake. Experiments to date with Gaussian shaped bunches have operated with transformer ratios between one and two. Recent analytic and numerical models have predicted that by optimizing the longitudinal profile, transformer ratios of five may be attained [22], e.g. a 1 GeV drive bunch with several nC of charge could boost the energy of a 1 nC, 1 GeV bunch to an energy of 5 GeV on the scale of a meter. In the example studied in Ref. [23], a 5-nC, 0.56-ps, 1-GeV drive bunch is able to accelerate a 0.35-nC, 23-fsec, 1-GeV trailing bunch to 5 GeV with an energy spread of less than 1%, with an energy conversion efficiency of 35% from drive to accelerated electrons and with preserved emittance. If these calculations prove out, this technol- ogy has the potential to reduce the length of LCLS by a factor of five with the same basic microwave accelerator technology, or even more significantly, lead to a vastly more compact system if the GeV drive beam is generated in a modern X-band accelerator, like the next linear collider test accelerator (NLCTA) at SLAC [24], with an overall footprint on the same order of magnitude as in a 10-GeV LPA. These types of preliminary experimental and numerical results, plus the high average-power capability of
Fig. 2. PWFA schematic, indicating plasma oscillations set up by drive electron bunch expelling plasma electrons from the path of the drive bunch. The PWFA is an attractive technology because existing microwave accelerators can efficiently produce high current bunches well suited for driving plasma wakes with fields over 10 GeV/m. The PWFA then acts as a transformer, converting one or more high current, low energy bunches into one or more relatively low current, high energy bunches. This process can be characterized by the ratio of the peak accelerating field to the peak de-accelerating field in the plasma wake, called the transformer ratio [21]. The transformer ratio can be manipulated by tailoring the longitudinal profile of the beams driving and sampling the plasma wake. Experiments to date with Gaussian shaped bunches have operated with transformer ratios between one and two. Recent analytic and numerical models have predicted that by optimizing the longitudinal profile, transformer ratios of five may be attained [22], e.g. a 1 GeV drive bunch with several nC of charge could boost the energy of a 1 nC, 1 GeV bunch to an energy of 5 GeV on the scale of a meter. In the example studied in Ref. [23], a 5-nC, 0.56-ps, 1-GeV drive bunch is able to accelerate a 0.35-nC, 23-fsec, 1-GeV trailing bunch to 5 GeV with an energy spread of less than 1%, with an energy conversion efficiency of 35% from drive to accelerated electrons and with preserved emittance. If these calculations prove out, this technol- ogy has the potential to reduce the length of LCLS by a factor of five with the same basic microwave accelerator technology, or even more significantly, lead to a vastly more compact system if the GeV drive beam is generated in a modern X-band accelerator, like the next linear collider test accelerator (NLCTA) at SLAC [24], with an overall footprint on the same order of magnitude as in a 10-GeV LPA. These types of preliminary experimental and numerical results, plus the high average-power capability of
Fig. 3. Inside the primary test vacuum chamber for the E-163 experiment. The electron beam enters from the right, passing through the 3-period permanent- magnet IFEL, and the compressor chicane to form optically bunched pulse trains.
Fig. 3. Inside the primary test vacuum chamber for the E-163 experiment. The electron beam enters from the right, passing through the 3-period permanent- magnet IFEL, and the compressor chicane to form optically bunched pulse trains.
Fig. 4. Sketches showing the three types of dielectric laser-driven accelerators being investigated at Stanford and SLAC. Expected accelerating gradients are derived from measured material damage threshold data at the specified wavelength on flat substrates.
Fig. 4. Sketches showing the three types of dielectric laser-driven accelerators being investigated at Stanford and SLAC. Expected accelerating gradients are derived from measured material damage threshold data at the specified wavelength on flat substrates.
Fig. 5. Inverse Compton scattering layout showing photoinjector, short linac, high power laser, bunch compressor, and interaction point. The challenges for development of light sources based on ICS are to tailor the electron and laser beam properties to produce the best possible X-ray beam. In general, very low emittance electron beams are required to produce both large X-ray fl uxes, due to the small interaction spot sizes required to produce a sufficient number of scattered photons, as well as high spectral brightness, due to the strong dependence of the X-ray beam s the electron beam divergence at the interaction pectral width on point. Addition- ally, relatively short pulse lengths for both the electron and laser beams are desired to maximize the interaction within the Rayleigh diffraction length of the laser beam. The optimization of high average flux, high spectral brightness inverse Compton scattering X-ray sources requires electron beams with low emittance (<1mm-mrad) and short pulse duration (<1 ps), and tightly focused (<5 um), short pulse ( <1 ps) lasers.
Fig. 5. Inverse Compton scattering layout showing photoinjector, short linac, high power laser, bunch compressor, and interaction point. The challenges for development of light sources based on ICS are to tailor the electron and laser beam properties to produce the best possible X-ray beam. In general, very low emittance electron beams are required to produce both large X-ray fl uxes, due to the small interaction spot sizes required to produce a sufficient number of scattered photons, as well as high spectral brightness, due to the strong dependence of the X-ray beam s the electron beam divergence at the interaction pectral width on point. Addition- ally, relatively short pulse lengths for both the electron and laser beams are desired to maximize the interaction within the Rayleigh diffraction length of the laser beam. The optimization of high average flux, high spectral brightness inverse Compton scattering X-ray sources requires electron beams with low emittance (<1mm-mrad) and short pulse duration (<1 ps), and tightly focused (<5 um), short pulse ( <1 ps) lasers.
Fig. 6. Numerically calculated on-axis brilliance divided by repetition rate vs. laser spot size and electron beam pulse duration assuming &.=1 Um, Xxe=10 |1m, At,=0.5 ps, A4=1 um, Q.=0.1 nc, and W,=10 mJ. The basic ICS technology is mature, with both laboratory and industrial ICS demonstrations. Increasing the performance of an ICS source depends on generating a very low emittance electron beam (0.1-1 mm-mrad) with relatively high average current (1-100 mA), parameters that are similar to requirements for electron beams driving X-ray FELs or ERLs, although the ICS operates at much lower final energy. The development of a CW photoinjector and its associated photocathode is important. The photoinjector can be either normal conducting (NC) RF (as the 100-mA, 700-MHz one currently being commissioned at LANL [44] or the mA-class photoinjector being designed at LBNL [45]), SRF (as the 0.5-A photoinjector being developed at BNL [46]), or DC (typically 10 s of PC from the JLAB injector [47]). The cathode may be normal conducting but may need to be compatible with a SRF cavity, have high quantum efficiency, low intrinsic emittance, rapid photo-response time (fs), and long lifetime. While super- conducting technology is well matched to the CW nature of this type of machine, it is not clear at this point if superconducting injectors will be able to match the beam brightness from NC injectors, which is needed. It is still an open research question if NC or SC will be the preferred injector technology of the future. While SRF technology has undergone rapid development for the large accelerators, the small-scale ICS would benefit from some changes in technical direction. The primary issues are the capital and operating costs, and size, for an SRF facility operating at 2 K. Successful development of CW, high-field SRF cavities operating at 4 K would have a significant impact on the size and cost of the ICS source. Such cavities must operate at lower frequencies
Fig. 6. Numerically calculated on-axis brilliance divided by repetition rate vs. laser spot size and electron beam pulse duration assuming &.=1 Um, Xxe=10 |1m, At,=0.5 ps, A4=1 um, Q.=0.1 nc, and W,=10 mJ. The basic ICS technology is mature, with both laboratory and industrial ICS demonstrations. Increasing the performance of an ICS source depends on generating a very low emittance electron beam (0.1-1 mm-mrad) with relatively high average current (1-100 mA), parameters that are similar to requirements for electron beams driving X-ray FELs or ERLs, although the ICS operates at much lower final energy. The development of a CW photoinjector and its associated photocathode is important. The photoinjector can be either normal conducting (NC) RF (as the 100-mA, 700-MHz one currently being commissioned at LANL [44] or the mA-class photoinjector being designed at LBNL [45]), SRF (as the 0.5-A photoinjector being developed at BNL [46]), or DC (typically 10 s of PC from the JLAB injector [47]). The cathode may be normal conducting but may need to be compatible with a SRF cavity, have high quantum efficiency, low intrinsic emittance, rapid photo-response time (fs), and long lifetime. While super- conducting technology is well matched to the CW nature of this type of machine, it is not clear at this point if superconducting injectors will be able to match the beam brightness from NC injectors, which is needed. It is still an open research question if NC or SC will be the preferred injector technology of the future. While SRF technology has undergone rapid development for the large accelerators, the small-scale ICS would benefit from some changes in technical direction. The primary issues are the capital and operating costs, and size, for an SRF facility operating at 2 K. Successful development of CW, high-field SRF cavities operating at 4 K would have a significant impact on the size and cost of the ICS source. Such cavities must operate at lower frequencies
Fig. 8. Efficiencies for HHG published in Refs. [51,52,55,56]. Fig. 7. Coherent scheme using an ultrarelativistic electron mirror: An ultraintense short pulse laser interacts with a nanometer foil, driving out all electrons. If the las: field is much stronger than the total restoring force exerted by the ions, the electrons can break out in a dense, ultra-short bunch, moving with a relativistic factor y. Th bunch can reflect an incoming second laser pulse and frequency upshift it by 4.
Fig. 8. Efficiencies for HHG published in Refs. [51,52,55,56]. Fig. 7. Coherent scheme using an ultrarelativistic electron mirror: An ultraintense short pulse laser interacts with a nanometer foil, driving out all electrons. If the las: field is much stronger than the total restoring force exerted by the ions, the electrons can break out in a dense, ultra-short bunch, moving with a relativistic factor y. Th bunch can reflect an incoming second laser pulse and frequency upshift it by 4.
Fig. 9. Evolution of the electric field in a linearly polarized 5 fs pulse of peak intensity 4.10!° W/cm? at 750 nm (thin line and ionization rate induced by this pulse in He (thick line). Barrier suppression field is 1.03 x 10° V/cm.
Fig. 9. Evolution of the electric field in a linearly polarized 5 fs pulse of peak intensity 4.10!° W/cm? at 750 nm (thin line and ionization rate induced by this pulse in He (thick line). Barrier suppression field is 1.03 x 10° V/cm.
Fig. 10. Sychrontron-type ICS source with multiple X-ray beamlines as a use! facility.
Fig. 10. Sychrontron-type ICS source with multiple X-ray beamlines as a use! facility.

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References (62)

  1. T. Tajima, J.M. Dawson, Phys. Rev. Lett. 43 (1979) 267.
  2. E. Esarey, C.B. Schroeder, W.P. Leemans, Rev. Mod. Phys. 81 (2009) 1229.
  3. W. Leemans, E. Esarey, Physics Today 63 (3) (2009) 44.
  4. T. Plettner, R. Byer, E. Colby, B. Cowan, C. Sears, J. Spencer, R. Siemann, PR-STAB 8 (2005) 121301.
  5. P. Chen, J.M. Dawson, R.W. Huff, T. Katsouleas, Phys. Rev. Lett. 64 (1985) 693.
  6. I. Blumenfeld, C.E. Clayton, F.J. Decker, M.J. Hogan, C. Huang, R. Ischebeck, R. Iverson, C. Joshi, T. Katsouleas, N. Kirby, W. Lu, K.A. Marsh, W.B. Mori, P. Muggli, E. Oz, R.H. Siemann, D. Walz, M. Zhou, Nature 445 (2006) 741.
  7. L.M. Brown, R.P. Feymann, Phys. Rev. 85 (2) (1952) 231.
  8. W.J. Brown, F.V. Hartemann, PR-STAB 7 (2004) 060703.
  9. P.B. Corkum, Phys. Rev. Lett. 71 (1993) 1994.
  10. M. Lewenstein, P. Balcou, et al., Phys. Rev. A 49 (1994) 2117.
  11. D.H. Whittum, A.M. Sessler, J.M. Dawson, Phys. Rev. Lett. 64 (1990) 2511.
  12. A. Rousse, K.T. Phuoc, R. Shah, A. Pukhov, E. Lefebvre, V. Malka, S. Kiselev, F. Burgy, J.-P. Rousseau, D. Umstadter, D. Hulin, Phys. Rev. Lett. 93 (2004) 135005.
  13. W.P. Leemans, B. Nagler, A.J. Gonsalves, C. Toth, K. Nakamura, C.G.R. Geddes, E. Esarey, C.B. Schroeder, S.M. Hooker, Nat. Phys. 2 (2006) 696.
  14. C.G.R. Geddes, C. Toth, J. Van Tilborg, E. Esarey, C.B. Schroeder, D. Bruhwiler, C. Nieter, J. Cary, W.P. Leemans, Nature 431 (7008) (2004) 538.
  15. F. Albert, R. Shah, K.T. Phuoc, R. Fitour, F. Burgy, J.-P. Rousseau, A. Tafzi, D. Douillet, T. Lefrou, A. Rousse, Phys. Rev. E 77 (2008) 056402.
  16. HHG seeding has been demonstrated at SPARC in the VUV (67 nm), L. Giannessi, Personal communication.
  17. C.B. Schroeder, W.M. Fawley, F. Gruner, M. Bakeman, K. Nakamura, K.E. Robinson, C. Toth, E. Esarey, W.P. Leemans, Free-electron laser driven by the LBNL laser- plasma accelerator, in: C.B. Schroeder, E. Esarey, W. Leemans (Eds.), Advanced Accelerator Concepts, vol. 1086, AIP, New York2009, pp. 637-642.
  18. Fuchs, et al., Nat. Phys. 5 (2009) 826.
  19. J.B. Rosenzweig, D.B. Cline, B. Cole, H. Figueroa, W. Gai, R. Konecny, J. Norem, P. Schoessow, J. Simpson, Phys. Rev. Lett. 61 (1988) 98.
  20. T. Katsouleas, Phys. Rev. A 33 (1986) 2056.
  21. C. Huang, et al., Phys. Rev. Lett. 99 (2007) 255001.
  22. C. Huang, et al., J. Comput. Phys. 217 (2006) 658.
  23. R. Ruth et al., Test accelerator for the next linear collider, SLAC PUB 6293, 1993.
  24. A.M. Sessler, D.H. Whittum, L.-H. Yu, Phys. Rev. Lett. 68 (1992) 309.
  25. C. Sears, E. Colby, B. Cowan, R. Siemann, J. Spencer, R. Byer, T. Plettner, PRL 95 (2005) 194801.
  26. C. Sears, E. Colby, R. Ischebeck, C. McGuinness, J. Nelson, R. Noble, R. Siemann, J. Spencer, D. Walz, T. Plettner, R. Byer, PRST-AB 11 (2008) 061301.
  27. C. Sears, E. Colby, R. England, R. Ischebeck, C. McGuinness, J. Nelson, R. Noble, R. Siemann, J. Spencer, D. Walz, T. Plettner, R. Byer, PRST-AB 11 (2008) 101301.
  28. X. Lin, PRST-AB 4 (2001) 051301.
  29. B. Cowan, PRST-AB 6 (2003) 101301.
  30. B. Cowan, PRST-AB 11 (2008) 011301.
  31. T. Plettner, P. Lu, R. Byer, PRST-AB 9 (2006) 111301.
  32. J. Rosenzweig, A. Murokh, C. Pellegrini, Phys. Rev. Lett. 74 (1995) 2467.
  33. C. McGuinness, E. Colby, R. Byer, J. Mod. Opt. 19 (2009).
  34. N. Na, R. Siemann, R. Byer, PRST-AB 8 (2005) 031301.
  35. T. Plettner, R. Byer, PRST-AB 11 (2008) 030704.
  36. P. Hommelhoff, C. Kealhofer, M. Kasevich, Mod. Trends Laser Phys. 19 (4) (2009) 736ff.
  37. E. Colby, et al., An electron source for a laser accelerator, in Proceedings of the PAC2005, 2005, p. 2101ff.
  38. D. Xiang, G. Stupakov, Phys. Rev. ST Accel. Beams 12 (2009) 030702.
  39. W.S. Graves, W.J. Brown, F.X. Kaertner, D.E. Moncton, Nucl. Instr. and Meth. 608 (i.1) (2009) s103.
  40. W.J. Brown, F.V. Hartemann, AIP Conf. Proc. 737 (2004) 839.
  41. J.B. Rosenzweig, O. Williams, Int. J. Mod. Phys. A 23 (2007) 4333.
  42. G.A. Krafft, Phys. Rev. Lett. 92 (2004) 204802.
  43. D.C. Nguyen, N.A. Moody, G. Bolme, L.J. Castellano, C.E. Heath, F.L. Krawczyk, S.I. Kwon, R. McCrady, F.A. Martinez, P. Marroquin, M. Prokop, P. Roybal, W.T. Roybal, T.L. Tomei, P.A. Torrez, W.M. Tuzel, L.M. Young, T. Zaugg, Endpoint energy measurements of field emission current in a CW normal- conducting RF injector, submitted for publication to PRST-AB (2010).
  44. K. Baptiste, J. Corlett, S. Kwiatkowski, S. Lidia, J. Qiang, F. Sannibale, K. Sonnad, J. Staples, S. Virostek, R. Wells, Nucl. Instr. and Meth. 599 (2009) 9.
  45. A. Burrill, I. Ben-Zvi, R. Calaga, X. Chang, H. Hahn, D. Kayran, J. Kewisch, V. Litvinenko, G. McIntyre, A. Nicoletti, D. Pate, J. Rank, J. Scaduto, R. Tao, K. Wu, A. Zaltsman, Y. Zhao, H. Bluem, M. Cole, M. Falletta, D. Holmes, E. Peterson, J. Rathke, T. Schultheiss, A. Todd, R. Wong, J. Lewellen, W. Funk, P. Kneisel, L. Phillips, J. Preble, D. Janssen, V. Nguyen-Tuong, Nucl. Instr. and Meth. 557 (2006) 75.
  46. C. Hernandez-Garcia et al., Performance and modeling of the JLAB IR FEL upgrade injector, in: Proceedings of the 26th International Free-electron Laser Conference, Trieste, Italy, 2004, p.558.
  47. J.B. Rosenzweig, M.P. Dunning, E. Hemsing, G. Marcus, P. Musumeci, A. Marinelli, M. Ferrario, Quasicrystalline beam formation in RF photoinjec- tors, in: Proceedings of the 30th International Free-Electron Laser Conference, Gyeongju, Korea, 2008.
  48. Kulagin, et al., Phys. Rev. Lett. 99 (2007) 124801.
  49. O. Klimo, J. Psikal, J. Limpouch, V.T. Tikhonchuk, PRST-AB 11 (2008) 031301.
  50. J.-F. Hergott, M. Kovacev, et al., Phys. Rev. A 66 (2002) 021801(R).
  51. E. Takahashi, Y. Nabekawa, et al., IEEE J. STQE 10 (2004) 1315.
  52. M. Schn ürer, Spielmann Ch., et al., Phys. Rev. Lett. 80 (1998) 3236.
  53. Z. Chang, A. Rundquist, et al., Phys. Rev. Lett. 79 (1997) 2967.
  54. I.J. Kim, C.M. Kim, et al., Phys. Rev. Lett. 94 (2005) 243901-1-4.
  55. E.J. Takahashi, et al., PRL 101 (2008) 253901.
  56. H.T. Kim, I.J. Kim, et al., IEEE J. STQE 10 (2004) 1329.
  57. E. Gibson, X. Zhang, et al., IEEE J. STQE 10 (2004) 1339.
  58. M. Nisoli, E. Priori, et al., Phys. Rev. Lett. 88 (2002) 33902-1.
  59. S. Kazamias, D. Douillet, et al., Phys Rev. Lett. 90 (2003) 193901-1.
  60. D. Dowell et al., Cathode R&D for future light sources, Nucl. Instr. and Meth., submited.
  61. N. Moody, et al., J. Appl. Phys. 102 (2007) 104901.
  62. See for example A. Tunnermann, J. Limpert, S. Nolte, Ultrashort pulse fiber lasers and amplifiers, in: Femtosecond Technology for Technical and Medical Applications, Springer, Berlin, ISSN 1437-0859, 2004.

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