IPAC2011 - List of Authors (Ding, Y.T.)

Paper	Title	Page
TUPC171	2D Optical Streaking for Ultra-short Electron Beam Diagnostics	1437
	L. Wang, Y.T. Ding, Z. Huang SLAC, Menlo Park, California, USA
	We propose a novel approach to measure the short electron bunch profile at micrometer level. Low energy electrons generated during beam-gas ionization are simultaneously modulated by the transverse electric field of a circularly-polarized laser, and then they are collected at a down-stream screen where the angular modulation are converted to a circular shape there. The longitudinal bunch profile is simply represented by the angular distribution of the electrons on the screen. We only need to know the laser wavelength for calibration and there is no phase synchronization problem. Meanwhile the required laser power is also relatively low in this setup. Some simulations examples and resolution of this method will be discussed.

THPC104	Optimization for Single-Spike X-Ray Fels at LCLS with a Low Charge Beam	3131
	L. Wang, Y.T. Ding, Z. Huang SLAC, Menlo Park, California, USA
	The recently commissioned Linac Coherent Light Source is an x-ray free-electron laser at the SLAC National Accelerator Laboratory, which is now operating at x-ray wavelengths of 20-1.2 Angstrom with peak brightness nearly ten orders of magnitude beyond conventional synchrotron sources. At the low charge operation mode (20 pC), the x-ray pulse length can be <10 fs. In this paper we report our numerical optimization and simulations to produce even shorter x-ray pulses by optimizing the machine and undulator setup. In the soft x-ray regime, with the help of slotted-foil or undulator taper, a single spike x-ray pulse is achievable with peak FEL power of 30 GW.

Paper

Title

Page

2D Optical Streaking for Ultra-short Electron Beam Diagnostics

1437

L. Wang, Y.T. Ding, Z. Huang
SLAC, Menlo Park, California, USA

We propose a novel approach to measure the short electron bunch profile at micrometer level. Low energy electrons generated during beam-gas ionization are simultaneously modulated by the transverse electric field of a circularly-polarized laser, and then they are collected at a down-stream screen where the angular modulation are converted to a circular shape there. The longitudinal bunch profile is simply represented by the angular distribution of the electrons on the screen. We only need to know the laser wavelength for calibration and there is no phase synchronization problem. Meanwhile the required laser power is also relatively low in this setup. Some simulations examples and resolution of this method will be discussed.

THPC104

Optimization for Single-Spike X-Ray Fels at LCLS with a Low Charge Beam

3131

L. Wang, Y.T. Ding, Z. Huang
SLAC, Menlo Park, California, USA

The recently commissioned Linac Coherent Light Source is an x-ray free-electron laser at the SLAC National Accelerator Laboratory, which is now operating at x-ray wavelengths of 20-1.2 Angstrom with peak brightness nearly ten orders of magnitude beyond conventional synchrotron sources. At the low charge operation mode (20 pC), the x-ray pulse length can be <10 fs. In this paper we report our numerical optimization and simulations to produce even shorter x-ray pulses by optimizing the machine and undulator setup. In the soft x-ray regime, with the help of slotted-foil or undulator taper, a single spike x-ray pulse is achievable with peak FEL power of 30 GW.