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J. K. Crane

First Name: J.

Middle Name: K.

Last Name: Crane

Full Name: J. K. Crane

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5 papers

title: Generation of High Brightness X-Rays with the PLEIADES Thomson X-Ray Source

format: conference procceeding

conference: 2003 Particle Accelerator Conference

year: 2003

14 authors: W. J. Brown | S. Anderson | C. P. J. Barty | J. K. Crane | R. R. Cross | D. N. Fittinghoff | F. V. Hartemann | J. Kuba | G. P. Le Sage | D. R. Slaughter | P. T. Springer | A. Tremaine | J. B. Rosenzweig | D. J. Gibson

abstract: The use of short laser pulses to generate high peak intensity, ultra-short x-ray pulses enables exciting new experimental capabilities, such as femtosecond pump-probe experiments used to temporally resolve material structural dynamics on atomic time scales. PLEIADES (Picosecond Laser Electron InterAction for the Dynamic Evaluation of Structures) is a next generation Thomson scattering x-ray source being developed at Lawrence Livermore National Laboratory (LLNL). Ultra-fast picosecond x-rays (10-200 keV) are generated by colliding an energetic electron beam (20-100 MeV) with a high intensity, sub-ps, 800 nm laser pulse. The peak brightness of the source is expected to exceed 1020 photons/s/0.1 bandwidth/mm2/mrad2. Simulations of the electron beam production, transport, and final focus are presented. Electron beam measurements, including emittance and final focus spot size are also presented and compared to simulation results. Measurements of x-ray production are also reported and compared to theoretical calculations.

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title: Electron Beam Production and Characterization for the PLEIADES Thomson X-Ray Source

format: conference procceeding

conference: 10th Advanced Accelerator Concepts Workshop

year: 2002

13 authors: W. J. Brown | F. V. Hartemann | A. Tremaine | P. T. Springer | G. P. Le Sage | C. P. J. Barty | J. B. Rosenzweig | J. K. Crane | R. R. Cross | D. N. Fittinghoff | D. J. Gibson | D. R. Slaughter | S. Anderson

abstract: We report on the performance of an S-band RF photocathode electron gun and accelerator for operation with the PLEIADES Thomson x-ray source at LLNL. Simulations of beam production, transport, and focus are presented. It is shown that a 1 ps, 500 pC electron bunch with a normalized emittance of less than 5 Tcmm-mrad can be delivered to the interaction point. Initial electron measurements are presented. Calculations of expected x-ray flux are also performed, demonstrating an expected peak spectral brightness of 1020 photons/s/mm2/mrad2/0.1% bandwidth. Effects of RF phase jitter are also presented, and planned phase measurements and control methods are discussed.

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title: Space-charge effects in high brightness electron beam emittance measurements

format: journal article

year: 2002

4 authors: S. Anderson | J. B. Rosenzweig | G. P. Le Sage | J. K. Crane

abstract: The measurement of emittance in space-charge dominated, high brightness beam systems is investigated from conceptual, computational, and experimental viewpoints. As the self-field-induced collective motion in the low energy, high brightness beams emitted from photoinjector rf guns are more important in determining the macroscopic beam evolution than thermal spreads in transverse velocity; traditional methods for phase space diagnosis fail in these systems. We discuss the role of space charge forces in a traditional measurement of transverse emittance, the quadrupole scan. The mitigation of these effects by use of multislit- or pepper-pot-based techniques is explained. The results of a direct experimental comparison between quadrupole scanning and slit-based determination of the emittance of a 5 MeV high brightness electron beam are presented. These data are interpreted with the aid of both envelope and multiparticle simulation codes. It is shown that the ratio of the beam's beta function to its transverse plasma wavelength plays a central role in the quadrupole scan results. Methods of determining the presence of systematic errors in quadrupole scan data are discussed.

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title: RF photoinjector development for a short-pulse, hard X-ray Thomson scattering source

format: conference procceeding

conference: 9th Advanced Accelerator Concepts Workshop

year: 2001

6 authors: G. P. Le Sage | S. G. Anderson | T. E. Cowan | J. K. Crane | T. Ditmire | J. B. Rosenzweig

abstract: An important motivation in the development of the next generation X-ray light sources is to achieve picosecond and sub-ps pulses of hard X-rays for dynamic studies of a variety of physical, chemical anti biological processes. Present hard X-ray sources are either pulse-width or intensity limited, which allows ps-scale temporal resolution only for signal averaging of highly repetitive processes. A much faster and brighter hard X-ray source is being developed at LLNL, based on Thomson scattering of fs-laser pulses by a relativistic electron beam, which will enable X-ray characterization of the transient structure of a sample in a single shot. Experimental and diagnostic techniques relevant to the development of next generation sources including the Linac Coherent Light Source can be tested with the Thomson scattering hard X-ray source. This source will combine an RF photoinjector with a 100 MeV S-band linac. The photoinjector and linac also provide an ideal test-bed for examining space-charge induced emittance growth effects. A program of beam dynamics and diagnostic experiments are planned in parallel with Thomson source development. Our experimental progress and future plans will be discussed.

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title: Experimental characterization of an ultrafast Thomson scattering x-ray source with three-dimensional time and frequency-domain analysis

format: journal article

year: 2004

18 authors: W. J. Brown | S. G. Anderson | C. P. J. Barty | S. M. Betts | R. Booth | J. K. Crane | R. R. Cross | D. N. Fittinghoff | D. J. Gibson | F. V. Hartemann | E. P. Hartouni | J. Kuba | G. P. Le Sage | D. R. Slaughter | A. M. Tremaine | A. J. Wootton | P. T. Springer | J. B. Rosenzweig

abstract: We present a detailed comparison of the measured characteristics of Thomson backscattered xrays produced at the Picosecond Laser-Electron Interaction for the Dynamic Evaluation of Structures facility at Lawrence Livermore National Laboratory to predicted results from a newly developed, fully three-dimensional time and frequency-domain code. Based on the relativistic differential cross section, this code has the capability to calculate time and space dependent spectra of the x-ray photons produced from linear Thomson scattering for both bandwidth-limited and chirped incident laser pulses. Spectral broadening of the scattered x-ray pulse resulting from the incident laser bandwidth, perpendicular wave vector components in the laser focus, and the transverse and longitudinal phase spaces of the electron beam are included. Electron beam energy, energy spread, and transverse phase space measurements of the electron beam at the interaction point are presented, and the corresponding predicted x-ray characteristics are determined. In addition, time-integrated measurements of the xrays produced from the interaction are presented and shown to agree well with the simulations.

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title:	Generation of High Brightness X-Rays with the PLEIADES Thomson X-Ray Source
format:	conference procceeding
conference:	2003 Particle Accelerator Conference
year:	2003
14 authors:	W. J. Brown \| S. Anderson \| C. P. J. Barty \| J. K. Crane \| R. R. Cross \| D. N. Fittinghoff \| F. V. Hartemann \| J. Kuba \| G. P. Le Sage \| D. R. Slaughter \| P. T. Springer \| A. Tremaine \| J. B. Rosenzweig \| D. J. Gibson
abstract:	The use of short laser pulses to generate high peak intensity, ultra-short x-ray pulses enables exciting new experimental capabilities, such as femtosecond pump-probe experiments used to temporally resolve material structural dynamics on atomic time scales. PLEIADES (Picosecond Laser Electron InterAction for the Dynamic Evaluation of Structures) is a next generation Thomson scattering x-ray source being developed at Lawrence Livermore National Laboratory (LLNL). Ultra-fast picosecond x-rays (10-200 keV) are generated by colliding an energetic electron beam (20-100 MeV) with a high intensity, sub-ps, 800 nm laser pulse. The peak brightness of the source is expected to exceed 1020 photons/s/0.1 bandwidth/mm2/mrad2. Simulations of the electron beam production, transport, and final focus are presented. Electron beam measurements, including emittance and final focus spot size are also presented and compared to simulation results. Measurements of x-ray production are also reported and compared to theoretical calculations.
keywords:
Download \| View \| Details \| edit \| delete

title:	Electron Beam Production and Characterization for the PLEIADES Thomson X-Ray Source
format:	conference procceeding
conference:	10th Advanced Accelerator Concepts Workshop
year:	2002
13 authors:	W. J. Brown \| F. V. Hartemann \| A. Tremaine \| P. T. Springer \| G. P. Le Sage \| C. P. J. Barty \| J. B. Rosenzweig \| J. K. Crane \| R. R. Cross \| D. N. Fittinghoff \| D. J. Gibson \| D. R. Slaughter \| S. Anderson
abstract:	We report on the performance of an S-band RF photocathode electron gun and accelerator for operation with the PLEIADES Thomson x-ray source at LLNL. Simulations of beam production, transport, and focus are presented. It is shown that a 1 ps, 500 pC electron bunch with a normalized emittance of less than 5 Tcmm-mrad can be delivered to the interaction point. Initial electron measurements are presented. Calculations of expected x-ray flux are also performed, demonstrating an expected peak spectral brightness of 1020 photons/s/mm2/mrad2/0.1% bandwidth. Effects of RF phase jitter are also presented, and planned phase measurements and control methods are discussed.
keywords:
Download \| View \| Details \| edit \| delete

title:	Space-charge effects in high brightness electron beam emittance measurements
format:	journal article
year:	2002
4 authors:	S. Anderson \| J. B. Rosenzweig \| G. P. Le Sage \| J. K. Crane
abstract:	The measurement of emittance in space-charge dominated, high brightness beam systems is investigated from conceptual, computational, and experimental viewpoints. As the self-field-induced collective motion in the low energy, high brightness beams emitted from photoinjector rf guns are more important in determining the macroscopic beam evolution than thermal spreads in transverse velocity; traditional methods for phase space diagnosis fail in these systems. We discuss the role of space charge forces in a traditional measurement of transverse emittance, the quadrupole scan. The mitigation of these effects by use of multislit- or pepper-pot-based techniques is explained. The results of a direct experimental comparison between quadrupole scanning and slit-based determination of the emittance of a 5 MeV high brightness electron beam are presented. These data are interpreted with the aid of both envelope and multiparticle simulation codes. It is shown that the ratio of the beam's beta function to its transverse plasma wavelength plays a central role in the quadrupole scan results. Methods of determining the presence of systematic errors in quadrupole scan data are discussed.
keywords:
Download \| View \| Details \| edit \| delete

title:	RF photoinjector development for a short-pulse, hard X-ray Thomson scattering source
format:	conference procceeding
conference:	9th Advanced Accelerator Concepts Workshop
year:	2001
6 authors:	G. P. Le Sage \| S. G. Anderson \| T. E. Cowan \| J. K. Crane \| T. Ditmire \| J. B. Rosenzweig
abstract:	An important motivation in the development of the next generation X-ray light sources is to achieve picosecond and sub-ps pulses of hard X-rays for dynamic studies of a variety of physical, chemical anti biological processes. Present hard X-ray sources are either pulse-width or intensity limited, which allows ps-scale temporal resolution only for signal averaging of highly repetitive processes. A much faster and brighter hard X-ray source is being developed at LLNL, based on Thomson scattering of fs-laser pulses by a relativistic electron beam, which will enable X-ray characterization of the transient structure of a sample in a single shot. Experimental and diagnostic techniques relevant to the development of next generation sources including the Linac Coherent Light Source can be tested with the Thomson scattering hard X-ray source. This source will combine an RF photoinjector with a 100 MeV S-band linac. The photoinjector and linac also provide an ideal test-bed for examining space-charge induced emittance growth effects. A program of beam dynamics and diagnostic experiments are planned in parallel with Thomson source development. Our experimental progress and future plans will be discussed.
keywords:
Download \| View \| Details \| edit \| delete

title:	Experimental characterization of an ultrafast Thomson scattering x-ray source with three-dimensional time and frequency-domain analysis
format:	journal article
year:	2004
18 authors:	W. J. Brown \| S. G. Anderson \| C. P. J. Barty \| S. M. Betts \| R. Booth \| J. K. Crane \| R. R. Cross \| D. N. Fittinghoff \| D. J. Gibson \| F. V. Hartemann \| E. P. Hartouni \| J. Kuba \| G. P. Le Sage \| D. R. Slaughter \| A. M. Tremaine \| A. J. Wootton \| P. T. Springer \| J. B. Rosenzweig
abstract:	We present a detailed comparison of the measured characteristics of Thomson backscattered xrays produced at the Picosecond Laser-Electron Interaction for the Dynamic Evaluation of Structures facility at Lawrence Livermore National Laboratory to predicted results from a newly developed, fully three-dimensional time and frequency-domain code. Based on the relativistic differential cross section, this code has the capability to calculate time and space dependent spectra of the x-ray photons produced from linear Thomson scattering for both bandwidth-limited and chirped incident laser pulses. Spectral broadening of the scattered x-ray pulse resulting from the incident laser bandwidth, perpendicular wave vector components in the laser focus, and the transverse and longitudinal phase spaces of the electron beam are included. Electron beam energy, energy spread, and transverse phase space measurements of the electron beam at the interaction point are presented, and the corresponding predicted x-ray characteristics are determined. In addition, time-integrated measurements of the xrays produced from the interaction are presented and shown to agree well with the simulations.
keywords:	pbpl
Download \| View \| Details \| edit \| delete

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