Evaluation of laser-irradiated Ar clusters as a source for time-resolved x-ray studies

Abstract

We have measured the absolute average photon flux, the spectral characteristics, and the time structure of x rays emitted from Ar clusters which were irradiated by a 100 fs laser with an intensity of 10 17 W/cm 2 . The measured photon flux was 10 7 photons per shot in the K ␣ ͑at 3 keV͒ line in a 4 sr solid angle. The temporal structure was measured using a streak camera with a 10 ps time resolution. It was found that less than 1% of the photons were emitted within the 10 ps time-response function of the streak camera. The emission profile is roughly exponential with a time constant of 3 ns.

Dynamics of rare gas nanoclusters irradiated by short and intense laser pulses

“…2 present similar durations. Thus these results are in disagreement with the results of Larsson and Sjogren [11] who reported a few ns duration for K-shell X-ray emission of Ar clusters, and greatly improve the measurements of Shiraishi et al [12] whose temporal resolution was 100 ps. Further, this indicates that a cluster-based X-ray source can be an efficient spectroscopic tool on ps time scale.…”

“…Cluster-based radiation sources are of interest provided the duration is in the subpicosecond range since the characteristic times of dynamical rearrangements in chemical reactions and condensed matter are about a few ps. In this respect, some controversial observations have been made in the multi-keV range: Larsson and Sjogren [11] reported a few ns duration for the K-shell X-ray emission of Ar clusters whereas Shiraishi et al [12] measured a duration of 100 ps for the M-shell of Xe clusters. Our primary aim is to resolve this controversy and thus determine whether clusterbased X-ray sources are relevant to ultrafast X-ray science.…”

Caractérisation spectrale et temporelle de l'émission X issue de l'interaction laser-agrégats

“…D'une part les modèles ne simulent pas le rayonnement X émis et ne proposent pas toujours de scénario en fonction du temps. D'autre part, deux équipes, qui ont réalisé des expériences avec une résolution temporelle poussée, ont obtenu des résultats contradictoires: Shiraishi et al mesurent une durée de 100 ps, limitée par la résolution temporelle, pour l'émission de 74 JOURNAL DE PHYSIQUE IV xénon en couche M (∼ 1 keV) [2], tandis que Larsson et al mesurent une durée caractéristique de l'ordre de 3 ns, avec une résolution temporelle de l'ordre de 10 ps, pour les raies de couche K de l'argon (∼ 3 keV) [3]. Malgré le nombre d'études réalisées, l'interaction laser intense-agrégat n'est pas encore bien comprise.…”

Interaction of intense laser pulses with atomic clusters: Measurements of ion emission, simulations and applications

“…In addition to a prompt X-ray component, time resolution of the X-ray emission using an X-ray streak-camera has shown that the most of the emission (around 99%) is emitted on a nanosecond timescale [15,61]. This implies that it is coming from the hot, underdense (n e < n crit ) plasma that is formed after the individual clusters have exploded and expanded to form a uniform, bulk plasma.…”