Abstract

An evaluation of the cone-shaped pickup performance as a part of the high bandwidth bunch arrival-time monitors (BAMs) for a low charge sub-10 fs arrival-time measurements is presented. Three sets of pickups are installed at the free electron laser FLASH at Deutsches Elektronen-Synchrotron, the quasi-cw SRF accelerator ELBE at the Helmholtz-Zentrum Dresden-Rossendorf and the SwissFEL injector test facility at Paul Scherrer Institute. Measurements and simulations are in good agreement and the pickups fulfill the design specifications. Utilizing the high bandwidth BAM with the cone-shaped pickups, an improvement of the signal slope by a factor of 10 is demonstrated at ELBE compared to the BAM with a low bandwidth.

Highlights

  • In order to study dynamical processes down to a femtosecond time scale, pump-probe experiments are conducted utilizing ultrashort x-ray pulses from free electron lasers (FELs) [1,2]

  • Utilizing the high bandwidth bunch arrival-time monitors (BAMs) with the cone-shaped pickups, an improvement of the signal slope by a factor of 10 is demonstrated at ELBE compared to the BAM with a low bandwidth

  • Unlike the measurements done at FLASH and ELBE, the measurements at the SwissFEL injector test facility are conducted outside the tunnel without loss of bandwidth of the measured pickup signal

Read more

Summary

INTRODUCTION

In order to study dynamical processes down to a femtosecond (fs) time scale, pump-probe experiments are conducted utilizing ultrashort x-ray pulses from free electron lasers (FELs) [1,2]. A resonant detection scheme utilizing a radio frequency (rf) phase difference from two single cell phase cavities at 2.805 GHz provides for a sub-50 fs arrivaltime measurements for bunch charges of 20 pC [9] This type of monitor is implemented at the Linac Coherent Light Source at Stanford Linear Accelerator Center. As an integral part of a laser-based synchronization system, the bunch arrival-time monitors (BAMs) measure the arrival time with a sub-10 fs time resolution for bunch charges higher than 500 pC [5] In this scheme, a transient beam-induced signal modulates the amplitude of an external laser pulse in a Mach-Zehnder type electro-optic modulator (EOM). Two different kinds of oscilloscopes were available for the measurements, a sampling oscilloscope at FLASH and a real time oscilloscope at the other facilities

Measurements at FLASH
GHz bottom
Measurements at ELBE
Measurements at the SwissFEL injector test facility
SUMMARY

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.