Design studies of a proof-of-principle experiment on THz SASE FEL at PITZ

X.-K Li ,Igor Isaev ,Raffael Niemczyk ,Matthias Groß ,F Stephan ,Christian Koschitzki ,Holger Huck ,A Oppelt ,Gregor Loisch ,Osip Lishilin ,David Melkumyan ,M Krasilnikov ,Guan Shu ,H Shaker,Houjun Qian ,Prach Boonpornprasert ,Y Chen ,Shankar Lal ,James Good ,G Vashchenko

doi:10.1088/1742-6596/1350/1/012036

X.-K Li , Igor Isaev + Show 18 more

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https://doi.org/10.1088/1742-6596/1350/1/012036

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Abstract

A free-electron laser based THz source is undergoing design studies at the Photo Injector Test facility at DESY in Zeuthen (PITZ). It is considered as a prototype for pump-probe experiments at the European XFEL, benefiting from the fact that the electron beam from the PITZ facility has an identical pulse train structure as the XFEL pulses. In the proposed proof-of-principle experiment, the electron beam (up to 4 nC bunch charge and 200 A peak current) will be accelerated to 16-22 MeV/c to generate SASE radiations in an LCLS-I undulator in the THz range between 60 and 100 pm with an expected energy of up to ~1 mJ/pulse. In this paper, we report our simulations on the optimization of the photo-injector and the design of the transport and matching beamline. Experimental investigations on the generation, characterization and matching of the high charge beam in the existing 22-m-long beamline will also be presented.

Highlights

As more user beamlines are put into use at the European X-ray free-electron laser facility (EuXFEL), pump-probe experiments will play an important role in many research frontiers in biology, chemistry and materials, etc [1, 2]
A free-electron laser based THz source is undergoing design studies at the Photo Injector Test facility at DESY in Zeuthen (PITZ). It is considered as a prototype for pump-probe experiments at the European XFEL, benefiting from the fact that the electron beam from the PITZ facility has an identical pulse train structure as the XFEL pulses
The advantages are: 1) it can produce the identical electron bunch train ( THz pulse train) as the X-ray pulses at EuXFEL; 2) the electron beam has moderate energy so no large beam dump is needed and 3) it can be installed near the user hall and is flexible in terms of the THz transportation

Summary

Introduction

As more user beamlines are put into use at the European X-ray free-electron laser facility (EuXFEL), pump-probe experiments will play an important role in many research frontiers in biology, chemistry and materials, etc [1, 2]. To provide the THz pump, proposals have been made at EuXFEL, for instance, by injecting the used electron beam into a super-conducting THz undulator [4]. Another promising idea is to put a separate PITZlike photo-injector near the user hall to drive the THz source [5].

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