Oscillator Seeding of a High Gain Harmonic Generation FEL in a Radiator-First Configuration
Abstract
A longitudinally coherent X-ray pulse from a high repetition rate free electron laser (FEL) is desired for a wide variety of experimental applications. However, generating such a pulse with a repetition rate greater than 1 MHz is a significant challenge. The desired high repetition rate sources, primarily high harmonic generation with intense lasers in gases or plasmas, do not exist now, and, for the multi-MHz bunch trains that superconducting accelerators can potentially produce, are likely not feasible with current technology. In this paper, we propose to place an oscillator downstream of a radiator. The oscillator generates radiation that is used as a seed for a high gain harmonic generation (HGHG) FEL which is upstream of the oscillator. For the first few pulses the oscillator builds up power and, until power is built up, the radiator has no HGHG seed. As power in the oscillator saturates, the HGHG is seeded and power is produced. The dynamics and stability of this radiator-first scheme is explored analytically and numerically. A single-pass map is derived using a semi-analytic model for FEL gain and saturation. Iteration of the map is shown to be in good agreement with simulations. A numerical example is presented for amore »
- Authors:
- Publication Date:
- Research Org.:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC)
- OSTI Identifier:
- 1171169
- Report Number(s):
- LBNL-6274E
- DOE Contract Number:
- DE-AC02-05CH11231
- Resource Type:
- Conference
- Resource Relation:
- Conference: International Particle Accelerator Conference IPAC'12, New Orleans, LA, May 20-25, 2012,
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 43 PARTICLE ACCELERATORS; oscillator seeding, high gain harmonic generation FEL, Radiator-First
Citation Formats
Gandhi, P., Wurtele, J., Penn, G., and Reinsch, M. Oscillator Seeding of a High Gain Harmonic Generation FEL in a Radiator-First Configuration. United States: N. p., 2012.
Web.
Gandhi, P., Wurtele, J., Penn, G., & Reinsch, M. Oscillator Seeding of a High Gain Harmonic Generation FEL in a Radiator-First Configuration. United States.
Gandhi, P., Wurtele, J., Penn, G., and Reinsch, M. Sun .
"Oscillator Seeding of a High Gain Harmonic Generation FEL in a Radiator-First Configuration". United States. https://www.osti.gov/servlets/purl/1171169.
@article{osti_1171169,
title = {Oscillator Seeding of a High Gain Harmonic Generation FEL in a Radiator-First Configuration},
author = {Gandhi, P. and Wurtele, J. and Penn, G. and Reinsch, M.},
abstractNote = {A longitudinally coherent X-ray pulse from a high repetition rate free electron laser (FEL) is desired for a wide variety of experimental applications. However, generating such a pulse with a repetition rate greater than 1 MHz is a significant challenge. The desired high repetition rate sources, primarily high harmonic generation with intense lasers in gases or plasmas, do not exist now, and, for the multi-MHz bunch trains that superconducting accelerators can potentially produce, are likely not feasible with current technology. In this paper, we propose to place an oscillator downstream of a radiator. The oscillator generates radiation that is used as a seed for a high gain harmonic generation (HGHG) FEL which is upstream of the oscillator. For the first few pulses the oscillator builds up power and, until power is built up, the radiator has no HGHG seed. As power in the oscillator saturates, the HGHG is seeded and power is produced. The dynamics and stability of this radiator-first scheme is explored analytically and numerically. A single-pass map is derived using a semi-analytic model for FEL gain and saturation. Iteration of the map is shown to be in good agreement with simulations. A numerical example is presented for a soft X-ray FEL.},
doi = {},
url = {https://www.osti.gov/biblio/1171169},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2012},
month = {5}
}