Development of an apparatus for characterization of cluster-gas targets for laser-driven particle accelerations

Jinno, Satoshi; Fukuda, Yuji; Sakaki, Hironao; Yogo, Akifumi; Kanasaki, Masato; Kondo, Kiminori; Faenov, A. Y.; Skobelev, I. Yu.*; Pikuz, T.; Boldarev, A. S.*; et al.

Progress in Ultrafast Intense Laser Science XI; Springer Series in Chemical Physics, Vol.109, p.215 - 233, 2015/00

https://doi.org/10.1007/978-3-319-06731-5_10

Clusters formed in supersonic gas expansion through a three-staged conical nozzle have been verified by measuring the angular distribution of the light scattered from cluster target. The size distirbutions of the clusters are calculated based on the Mie theory. The reliability of the size measurement is verified to be an experimental error of 10% using standard particles. The mean sizes of CO clusters for the cases of CO/H and CO/He mixed-gas targets are estimated to be 0.26 m and 0.22 m, respectively. For the CO/H, the cluster density is estimated to be 5.5 clusters/cm by measuring the attenuation of the laser beam intensity. Furthermore, total gas density profiles are obtained via the Abel inversion from the phase shift of the light passing through the target using an interferometer. The variation of the cluster mass fraction along the radial direction of the target is almost constant, which is consistent with a Boldarev's model.

Characterization of submicron-sized CO clusters formed with a supersonic expansion of a mixed-gas using a three-staged nozzle

Jinno, Satoshi; Fukuda, Yuji; Sakaki, Hironao; Yogo, Akifumi; Kanasaki, Masato; Kondo, Kiminori; Faenov, A. Ya.*; Skobelev, I. Yu.*; Pikuz, T.; Boldarev, A. S.*; et al.

Applied Physics Letters, 102(16), p.164103_1 - 164103_4, 2013/04

https://doi.org/10.1063/1.4802915

The size of CO clusters, produced in a supersonic expansion of a mixed-gas of CO/He or CO/H through a three-staged conical nozzle designed based on the Boldarev's model, has been evaluated by measuring the angular distribution of light scattered from the clusters. The data are analyzed utilizing the Mie scattering theory, and the sizes of CO clusters are estimated as 0.22 m and 0.25 m for the cases of CO/He and CO/H gas mixtures, respectively. The results confirm that the Boldarev's model is reliable enough for the production of micron-sized clusters.

Ion acceleration in subcritical density plasma via interaction of intense laser pulse with cluster-gas target

Fukuda, Yuji; Faenov, A.*; Tampo, Motonobu; Pikuz, T.*; Nakamura, Tatsufumi; Kando, Masaki; Hayashi, Yukio; Yogo, Akifumi; Sakaki, Hironao; Kameshima, Takashi*; et al.

Progress in Ultrafast Intense Laser Science VII, p.225 - 240, 2011/05

http://www.springer.com/physics/atomic,+molecular,+optical+%26+plasma+physics/book/978-3-642-18326-3

We present substantial enhancement of the accelerated ion energies up to 10-20 MeV per nucleon by utilizing the unique properties of the cluster-gas target irradiated with 40-fs laser pulses of only 150 mJ energy, corresponding to approximately tenfold increase in the ion energies compared to previous experiments using thin foil targets. A particle-in-cell simulation infers that the high energy ions are generated at the rear side of the target due to the formation of a strong dipole vortex structure in sub-critical density plasmas. The demonstrated method can be important in the development of efficient laser ion accelerators for hadron therapy and other applications.

Energy increase in multi-MeV ion acceleration in the interaction of a short pulse laser with a cluster-gas target

Fukuda, Yuji; Faenov, A. Y.; Tampo, Motonobu; Pikuz, T. A.*; Nakamura, Tatsufumi; Kando, Masaki; Hayashi, Yukio; Yogo, Akifumi; Sakaki, Hironao; Kameshima, Takashi*; et al.

Physical Review Letters, 103(16), p.165002_1 - 165002_4, 2009/10

https://doi.org/10.1103/PhysRevLett.103.165002

A new approach for accelerating ions, based on the use of a cluster-gas target and a compact ultrashort pulse laser, is presented. It is shown that ions with energy 10-20 MeV per nucleon having a small divergence (full angle) of 3.4 are generated, corresponding to an approximately tenfold increase in the ion energies compared to previous experiments using solid targets. It is inferred from a particle-in-cell code simulation that the high energy ions are generated at the rear side of the target due to the formation of a strong dipole vortex structure in near-critical density plasmas.

Ion acceleration in the interaction of short pulse laser radiation with the cluster-gas target

Fukuda, Yuji; Faenov, A. Y.; Tampo, Motonobu; Pikuz, T. A.*; Nakamura, Tatsufumi; Kando, Masaki; Hayashi, Yukio; Yogo, Akifumi; Sakaki, Hironao; Kameshima, Takashi; et al.

AIP Conference Proceedings 1153, p.85 - 93, 2009/07

https://doi.org/10.1063/1.3204561

When the target consists of solid-density clusters embedded in the background gas, its irradiation by high intensity laser light renders ion acceleration a truly unique property. We present that the cluster-gas target, which consists of submicron-sized clusters and background gases, irradiated by a few TW laser pulse produces high energy ions upward of the order of 10-20 MeV/n in the forward direction.

Separation of emission lines of multiply charged ions against background of a very noisy spectrum of femtosecond laser plasma

Gasilov, S. V.*; Faenov, A. Y.

Instruments and Experimental Techniques, 51(2), p.205 - 212, 2008/03

https://doi.org/10.1134/S0020441208020097

Generation of fast ions by an efficient coupling of high power laser into snow nanotubes

Palchan, T.*; Henis, Z.*; Faenov, A. Y.; Magunov, A. I.*; Pikuz, S. A.*; Gasilov, S. V.*; Skobelev, I. Yu.*; Zigler, A.*

Applied Physics Letters, 91(25), p.251501_1 - 251501_3, 2007/12

https://doi.org/10.1063/1.2820388

Extracting ion emission lines from femtosecond-laser plasma X-ray spectra heavily contaminated by spikes

Gasilov, S. V.*; Faenov, A. Y.; Pikuz, T. A.*; Villoresi, P.*; Poletto, L.*; Stagira, S.*; Calegari, F.*; Vozzi, C.*; Nisoli, M.*

Journal of Applied Physics, 102(6), p.063303_1 - 063303_7, 2007/00

https://doi.org/10.1063/1.2780872

Generation of X-rays and energetic ions from superintense laser irradiation of micron-sized Ar clusters

Fukuda, Yuji; Akahane, Yutaka; Aoyama, Makoto; Inoue, Norihiro*; Ueda, Hideki; Kishimoto, Yasuaki; Yamakawa, Koichi; Faenov, A. Y.*; Magunov, A. I.*; Pikuz, T. A.*; et al.

Laser and Particle Beams, 22(3), p.215 - 220, 2004/07

https://doi.org/10.1017/S0263034604223047

High resolution K-shell spectra of a plasma created by superintense laser irradiation of micron-sized Ar clusters have been measured with an intensity above 10 W/cm and a pulse duration of 30 fs. The total photon flux of 210 photons/pulse was achieved for He resonant line of Ar (=3.9491 AA , 3.14 keV). In parallel with X-ray measurements, energy distributions of emitted ions have been measured. The multiply-charged ions with kinetic energies up to 800 keV were observed. It is found that hot electrons produced by high contrast laser pulses allow the isochoric heating of clusters and shift the ion balance towards the higher charge states, which enhances both the X-ray line yield of the He-like argon ion and the ion kinetic energy.

X-ray study of microdroplet plasma formation under the action of superintense laser radiation

Fukuda, Yuji; Yamakawa, Koichi; Akahane, Yutaka; Aoyama, Makoto; Inoue, Norihiro*; Ueda, Hideki; Abdallah, J. Jr.*; Csanak, G.*; Faenov, A. Y.*; Magunov, A. I.*; et al.

JETP Letters, 78(3), p.115 - 118, 2003/08

https://doi.org/10.1134/1.1618874

We have measured the X-ray emission spectra of a plasma generated by laser radiation with an intensity above 10 W/cm and a pulse duration of 30 fs acting uon an argon jet target with a large aboundance of micron-sized clusters. The time variation of the X-ray yeild from various multiplicities, calculated within the framework of a nonstationary kinetic model, shows a good qualitative agreement with the experimental time-integrated spectrum.