title: Towards jitter-free pump-probe measurements at seeded free electron laser facilities.
abstract: X-ray free electron lasers (FEL) coupled with optical lasers have opened unprecedented opportunities for studying ultrafast dynamics in matter. The major challenge in pump-probe experiments using FEL and optical lasers is synchronizing the arrival time of the two pulses. Here we report a technique that benefits from the seeded-FEL scheme and uses the optical seed laser for nearly jitter-free pump-probe experiments. Timing jitter as small as 6 fs has been achieved and confirmed by measurements of FEL-induced transient reflectivity changes of Si3N4 using both collinear and non-collinear geometries. Planned improvements of the experimental set-up are expected to further reduce the timing jitter between the two pulses down to fs level.
authors.forename: Miltcho B
authors.initials: MB
authors.lastname: Danailov
authors.forename: Filippo
authors.initials: F
authors.lastname: Bencivenga
authors.forename: Flavio
authors.initials: F
authors.lastname: Capotondi
authors.forename: Francesco
authors.initials: F
authors.lastname: Casolari
authors.forename: Paolo
authors.initials: P
authors.lastname: Cinquegrana
authors.forename: Alexander
authors.initials: A
authors.lastname: Demidovich
authors.forename: Erika
authors.initials: E
authors.lastname: Giangrisostomi
authors.forename: Maya P
authors.initials: MP
authors.lastname: Kiskinova
authors.forename: Gabor
authors.initials: G
authors.lastname: Kurdi
authors.forename: Michele
authors.initials: M
authors.lastname: Manfredda
authors.forename: Claudio
authors.initials: C
authors.lastname: Masciovecchio
authors.forename: Riccardo
authors.initials: R
authors.lastname: Mincigrucci
authors.forename: Ivaylo P
authors.initials: IP
authors.lastname: Nikolov
authors.forename: Emanuele
authors.initials: E
authors.lastname: Pedersoli
authors.forename: Emiliano
authors.initials: E
authors.lastname: Principi
authors.forename: Paolo
authors.initials: P
authors.lastname: Sigalotti