FEL2014 - List of Authors (Penn, G.)

Paper	Title	Page
MOP054	Harmonic Lasing Options for LCLS-II	148
	G. Marcus, Y. Ding, Z. Huang, T.O. Raubenheimer SLAC, Menlo Park, California, USA G. Penn LBNL, Berkeley, California, USA
	Harmonic lasing can be a cheap and relatively efficient way to extend the photon energy range of a particular FEL beamline. Furthermore, in comparison to nonlinear harmonics, harmonic lasing can provide a beam that is more intense, stable, and narrow-band. This paper explores the application of the harmonic lasing concept at LCLS-II using various combinations of phase shifters and attenuators. In addition, a scheme by which individual undulator modules are tuned to amplify either the third or fifth harmonic in different configurations is presented in detail.

MOP075	Laser Seeding Schemes for Soft X-rays at LCLS-II	223
	G. Penn LBNL, Berkeley, California, USA P. Emma, E. Hemsing, G. Marcus, T.O. Raubenheimer, L. Wang SLAC, Menlo Park, California, USA
	Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract Nos. DE-AC02-05CH11231 and DE-AC02-76SF00515. The initial design for LCLS-II incorporates both SASE and self-seeded configurations. Increased stability and/or coherence than is possible with either configuration may be provided by seeding with external lasers followed by one or more stages of harmonic generation, especially in the soft x-ray regime. External seeding also allows for increased flexibility, for example the ability to quickly vary the pulse duration. Studies of schemes based on high-gain harmonic generation and echo-enabled harmonic generation are presented, including realistic electron distributions based on tracking through the injector and linac.

TUP033	Broadly Tunable Free-Electron Laser for Four-wave Mixing Experiments with Soft X-ray Pulses	461
	G. Marcus SLAC, Menlo Park, California, USA G. Penn LBNL, Berkeley, California, USA A. Zholents ANL, Argonne, Illinois, USA
	This paper examines a FEL design for the production of three soft x-ray pulses from a single electron beam suitable for four-wave mixing experiments. Independent control of the wavelength, timing and angle of incidence of the three ultra-short, ultra-intense pulses with exquisite synchronization is critical. A process of selective amplification where a chirped electron beam and a tapered undulator are used to isolate the gain region to only a short fraction of the electron beam is explored in detail. Numerical particle simulations are used to demonstrate the essential features of this scheme in the context of the LCLS-II design study.

Paper

Title

Page

Harmonic Lasing Options for LCLS-II

148

G. Marcus, Y. Ding, Z. Huang, T.O. Raubenheimer
SLAC, Menlo Park, California, USA
G. Penn
LBNL, Berkeley, California, USA

Harmonic lasing can be a cheap and relatively efficient way to extend the photon energy range of a particular FEL beamline. Furthermore, in comparison to nonlinear harmonics, harmonic lasing can provide a beam that is more intense, stable, and narrow-band. This paper explores the application of the harmonic lasing concept at LCLS-II using various combinations of phase shifters and attenuators. In addition, a scheme by which individual undulator modules are tuned to amplify either the third or fifth harmonic in different configurations is presented in detail.

MOP075

Laser Seeding Schemes for Soft X-rays at LCLS-II

223

G. Penn
LBNL, Berkeley, California, USA
P. Emma, E. Hemsing, G. Marcus, T.O. Raubenheimer, L. Wang
SLAC, Menlo Park, California, USA

Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract Nos. DE-AC02-05CH11231 and DE-AC02-76SF00515.
The initial design for LCLS-II incorporates both SASE and self-seeded configurations. Increased stability and/or coherence than is possible with either configuration may be provided by seeding with external lasers followed by one or more stages of harmonic generation, especially in the soft x-ray regime. External seeding also allows for increased flexibility, for example the ability to quickly vary the pulse duration. Studies of schemes based on high-gain harmonic generation and echo-enabled harmonic generation are presented, including realistic electron distributions based on tracking through the injector and linac.

TUP033

Broadly Tunable Free-Electron Laser for Four-wave Mixing Experiments with Soft X-ray Pulses

461

G. Marcus
SLAC, Menlo Park, California, USA
G. Penn
LBNL, Berkeley, California, USA
A. Zholents
ANL, Argonne, Illinois, USA

This paper examines a FEL design for the production of three soft x-ray pulses from a single electron beam suitable for four-wave mixing experiments. Independent control of the wavelength, timing and angle of incidence of the three ultra-short, ultra-intense pulses with exquisite synchronization is critical. A process of selective amplification where a chirped electron beam and a tapered undulator are used to isolate the gain region to only a short fraction of the electron beam is explored in detail. Numerical particle simulations are used to demonstrate the essential features of this scheme in the context of the LCLS-II design study.