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Micron-scale Laser-wire at the ATF-II at KEK Commissioning and Results

Proceedings of IPAC 11 1401-1403

Authors:

LJ Nevay, L Corner, R Walczak, GA Blair, ST Boogert, L Deacon, P Karataev, A Aryshev, N Terunuma, J Urakawa

Abstract:

We present the first results from the commissioning of the upgraded laser-wire experiment at the Accelerator Test Facility 2 (ATF-II) at KEK. A new laser transport line and beam diagnostics were used to collide 150 mJ, 167 ps long laser pulses with 1.28 GeV, 30 ps long electron bunches to measure the vertical transverse size. Additionally, a new detector was installed with a reduced area for lower background. Initial scans showing a convoluted beam size of 18.4 ± 0.4 μm were used to tune the electron beam optics and reduce this down to 8.0 ± 0.3 μm. Laser pulse energy and charge dependency were investigated showing a linear relationship in both with a minimum laser energy of 20 mJ required for adequate signal to make a laser-wire scan.

Photonic crystal fibre laser for electron beam measurement

Proceedings of IPAC 11 577-579

Authors:

L Corner, LJ Nevay, R Walczak

Abstract:

We present the successful development of a new fibre laser system for a laser-wire electron beam emittance diagnostic, suitable for intra-train scanning in an ILC-specification environment. The system is based on the amplification of a commercial Ytterbium (Yb) fibre laser with a repetition rate of 6.49MHz in rod type Yb doped photonic crystal fibre (PCF). We demonstrate world leading laser performance, with amplification of pulses from 1.5uJ to 268uJ and a beam quality factor M2 < 1.1, in 1ms bursts at 2Hz.