Open AccessPhoton diagnostics at the FLASH THz beamline
Author(s) -
Pan Rui,
Zapolnova Ekaterina,
Golz Torsten,
Krmpot Aleksandar J.,
Rabasovic Mihailo D.,
Petrovic Jovana,
Asgekar Vivek,
Faatz Bart,
Tavella Franz,
Perucchi Andrea,
Kovalev Sergey,
Green Bertram,
Geloni Gianluca,
Tanikawa Takanori,
Yurkov Mikhail,
Schneidmiller Evgeny,
Gensch Michael,
Stojanovic Nikola
Publication year - 2019
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577519003412
Subject(s) - beamline , optics , terahertz radiation , desy , laser , ultrashort pulse , spectrometer , physics , free electron laser , pulse duration , optoelectronics , materials science , beam (structure)
The THz beamline at FLASH, DESY, provides both tunable (1–300 THz) narrow‐bandwidth (∼10%) and broad‐bandwidth intense (up to 150 uJ) THz pulses delivered in 1 MHz bursts and naturally synchronized with free‐electron laser X‐ray pulses. Combination of these pulses, along with the auxiliary NIR and VIS ultrashort lasers, supports a plethora of dynamic investigations in physics, material science and biology. The unique features of the FLASH THz pulses and the accelerator source, however, bring along a set of challenges in the diagnostics of their key parameters: pulse energy, spectral, temporal and spatial profiles. Here, these challenges are discussed and the pulse diagnostic tools developed at FLASH are presented. In particular, a radiometric power measurement is presented that enables the derivation of the average pulse energy within a pulse burst across the spectral range, jitter‐corrected electro‐optical sampling for the full spectro‐temporal pulse characterization, spatial beam profiling along the beam transport line and at the sample, and a lamellar grating based Fourier transform infrared spectrometer for the on‐line assessment of the average THz pulse spectra. Corresponding measurement results provide a comprehensive insight into the THz beamline capabilities.