Open AccessVery high brightness and power LCLS‐II hard X‐ray pulses
Author(s) -
Halavanau Aliaksei,
Decker Franz-Josef,
Emma Claudio,
Sheppard Jackson,
Pellegrini Claudio
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/s1600577519002492
Subject(s) - undulator , optics , physics , monochromator , tapering , bandwidth (computing) , linear particle accelerator , photon energy , photon , brightness , advanced photon source , pulse duration , particle accelerator , radiation , laser , beam (structure) , wavelength , computer graphics (images) , computer science , computer network
The feasibility of generating X‐ray pulses in the 4–8 keV fundamental photon energy range with 0.65 TW peak power, 15 fs pulse duration and 9 × 10 −5 bandwidth using the LCLS‐II copper linac and hard X‐ray (HXR) undulator is shown. In addition, third‐harmonic pulses with 8–12 GW peak power and narrow bandwidth are also generated. High‐power and small‐bandwidth X‐rays are obtained using two electron bunches separated by about 1 ns, one to generate a high‐power seed signal, the other to amplify it through the process of the HXR undulator tapering. The bunch delay is compensated by delaying the seed pulse with a four‐crystal monochromator. The high‐power seed leads to higher output power and better spectral properties, with more than 94% of the X‐ray power within the near‐transform‐limited bandwidth. Some of the experiments made possible by X‐ray pulses with these characteristics are discussed, such as single‐particle imaging and high‐field physics.