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Journal Articles

Acceleration of highly charged GeV Fe ions from a low-Z substrate by intense femtosecond laser

Nishiuchi, Mamiko; Sakaki, Hironao; Esirkepov, T. Z.; Nishio, Katsuhisa; Pikuz, T.*; Faenov, A.*; Skobelev, I. Yu.*; Orlandi, R.; Sako, Hiroyuki; Pirozhkov, A. S.; et al.

Physics of Plasmas, 22(3), p.033107_1 - 033107_8, 2015/03

 Times Cited Count:53 Percentile:1.9(Physics, Fluids & Plasmas)

Almost fully stripped Fe ions accelerated up to 0.9 GeV are demonstrated with a 200 TW femtosecond high-intensity laser irradiating a micron-thick Al foil with Fe impurity on the surface. An energetic low-emittance high-density beam of heavy ions with a large charge-to-mass ratio can be obtained, which is useful for many applications, such as a compact radio isotope source in combination with conventional technology.

Journal Articles

Measurements of electron-induced neutrons as a tool for determination of electron temperature of fast electrons in the task of optimization laser-produced plasma ions acceleration

Sakaki, Hironao; Nishiuchi, Mamiko; Maeda, Shota; Sagisaka, Akito; Pirozhkov, A. S.; Pikuz, T.; Faenov, A.*; Ogura, Koichi; Fukami, Tomoyo; Matsukawa, Kenya*; et al.

Review of Scientific Instruments, 85(2), p.02A705_1 - 02A705_4, 2014/02

 Times Cited Count:2 Percentile:85.32(Instruments & Instrumentation)

High intensity laser-plasma interaction has attracted considerable interest for a number of years. The laser-plasma interaction is accompanied by generation of various charged particle beams. Results of simultaneous novel measurements of electron-induced photonuclear neutrons (photoneutron), which are a diagnostic of the laser-plasma interaction, are proposed to use for optimization of the laser-plasma ion generation. The proposed method is demonstrated by the laser irradiation with the intensity os 1$$times$$10$$^{21}$$ W/cm$$^{2}$$ on the metal foil target. The photoneutrons are measured by using NE213 liquid scintillation detectors. Heavy-ion signal is registered with the CR39 track detector simultaneously. The measured signals of the electron-induced photoneutrons are well reproduced by using the Particle and Heavy Ion Transport code System (PHITS). The results obtained provide useful approach for analyzing the various laser based ion beams.

Oral presentation

Response characterization of ZnS(Ag) screen for on-line imaging diagnosis of laser-accelerated ion beams

Kanasaki, Masato; Sakaki, Hironao; Fukuda, Yuji; Yogo, Akifumi; Jinno, Satoshi; Kondo, Kiminori; Akagi, Takashi*; Hattori, Atsuto*; Matsukawa, Kenya*; Oda, Keiji*; et al.

no journal, , 

In the laser-driven ion acceleration experiment, fast electrons and X-rays also generated and these particles could cause significant contaminants to the ion detectors an a background noise. In the present study, to minimize the noise signals, we have optimized thickness of ZnS(Ag) fluorescent screen, which is much sensitive for ions, through Monte Carlo particle transport code PHITS. And we have also evaluate the response of the fluorescent screen as a function of fluence using rf-accelerator.

Oral presentation

Design of a wide energy range stacked CR-39 detector diminishing contaminant photo-neutrons using Monte Carlo particle transport simulations

Kanasaki, Masato; Fukuda, Yuji; Sakaki, Hironao; Yogo, Akifumi; Jinno, Satoshi; Nishiuchi, Mamiko; Hattori, Atsuto*; Matsukawa, Kenya*; Kondo, Kiminori; Oda, Keiji*; et al.

no journal, , 

A CR-39 detector has been widely utilized in the laser-driven ion acceleration experiments. In our experiments applying cluster-gas target, along with high energy ions with several tens of MeV, a significant amount of well-collimated high energy electrons with similar energies are produced. Such fast electrons could produce high energy photons. Furthermore, such photons could produce photo-neutrons. If the CR-39 is exposed to such photo-neutrons, it can record recoiled protons and other heavy ions generated by the photo-neutrons. In order to precisely diagnose only for laser accelerated protons and heavy ions, we have to keep the photo-neutron fluence level as low as possible. In the present study, to minimize the effect of photo-neutrons, we have optimized the geometry of the CR-39 detector unit by using Monte Carlo particle transport code PHITS. The developed detector unit allows us to diagnose the laser-accelerated ions up to several hundred MeV with less effect from photo-neutrons.

Oral presentation

A Diagnosis of laser-accelerated ion beams considered with photo-neutrons contaminants

Kanasaki, Masato; Fukuda, Yuji; Sakaki, Hironao; Yogo, Akifumi; Jinno, Satoshi; Nishiuchi, Mamiko; Hattori, Atsuto*; Matsukawa, Kenya*; Kondo, Kiminori; Oda, Keiji*; et al.

no journal, , 

In laser-driven ion acceleration experiments applying cluster-gas target, along with high energy ions, a significant amount of well-collimated high energy electrons with several hundreds of MeV are produced. Such fast electrons could produce high energy photons via bremsstrahlung processes. Furthermore, such photons could produce photo-neutrons in a series of ($$gamma$$,n) reactions. If CR-39 detectors, which can detect only ions and it is insensitive to high energy photons and electrons, is exposed to such photo-neutrons, it can record recoiled protons and other heavy ions generated by the nuclear reactions. In order to precisely diagnose only for laser accelerated ions, we have to keep the photo-neutron flux level as low as possible, because it could cause significant contaminant effects to the CR-39 as a background noise. In the present study, to minimize the flux of photo-neutrons, we have considered the geometry of the stacked CR-39 detector unit by using Monte Carlo simulation.

Oral presentation

A Study on the effect of photo-neutrons on laser-accelerated ion beam diagnostics

Kanasaki, Masato; Fukuda, Yuji; Sakaki, Hironao; Yogo, Akifumi; Jinno, Satoshi; Nishiuchi, Mamiko; Hattori, Atsuto*; Matsukawa, Kenya*; Kondo, Kiminori; Oda, Keiji*; et al.

no journal, , 

In laser-driven ion acceleration experiments with cluster-gas targets, a significant amount of high energy electrons are produced. Such fast electrons can produce photo-neutrons via bremsstrahlung processes followed by ($$gamma$$,n) reactions. If the CR-39 is exposed to photo-neutrons, it can record proton tracks indirectly as background noises. In the present study, to diminish the effect of photo-neutrons, we have considered the configuration of a beam dump for high energy electrons and a CR-39 detector unit by using Monte Carlo simulations.

Oral presentation

The Effect of photo-neutrons on diagnostics using CR-39 for laser-accelerated ion beam

Kanasaki, Masato; Fukuda, Yuji; Sakaki, Hironao; Yogo, Akifumi; Jinno, Satoshi; Nishiuchi, Mamiko; Hattori, Atsuto*; Matsukawa, Kenya*; Kondo, Kiminori; Oda, Keiji*; et al.

no journal, , 

In laser-driven ion acceleration experiments applying cluster-gas targets, a significant amount of high energy electrons are produced. Such fast electrons can produce photo-neutrons via bremsstrahlung processes followed by ($$gamma$$,n) reactions. When the CR-39 is exposed to photo-neutrons, it records etchable tracks of generated ions depending on their species and energy as background noises. To minimize the effect of photo-neutrons, the configuration of the CR-39 detector unit and beam dump for high energy electrons has been examined by Monte Carlo simulations. As a result, we have found the suitable configuration for CR-39 to detect only laser-accelerated ions with less contaminant by photo-neutrons in one laser shot.

Oral presentation

Laser-driven proton generation from a thin-foil target with a high-intensity laser

Sagisaka, Akito; Nishiuchi, Mamiko; Pirozhkov, A. S.; Ogura, Koichi; Sakaki, Hironao; Maeda, Shota; Pikuz, T.; Faenov, A. Ya.*; Fukuda, Yuji; Yogo, Akifumi; et al.

no journal, , 

High-intensity laser and thin-foil interactions produce high-energy particles, hard X-ray, high-order harmonics, and terahertz radiation. A proton beam driven by a high-intensity laser has received attention as a compact ion source for medical and other applications. We have performed several high intensity laser-matter interaction experiments using a thin-foil target irradiated by Ti:sapphire laser (J-KAREN) at JAEA. The pulse duration was typically $$sim$$ 40 fs (FWHM). The electron density profiles of the preformed plasma were observed with the interferometer. The high temporal contrast laser system could reduce the preformed plasma. The maximum proton energy gradually increased as the laser performance improved and finally protons of $$sim$$ 40 MeV energy were observed at the peak laser intensity of $$sim$$ 1 $$times$$ 10$$^{21}$$ W/cm$$^{2}$$.

Oral presentation

A Diagnosis method of laser-accelerated protons using CR-39 in a field contaminated by photo-neutrons

Kanasaki, Masato; Fukuda, Yuji; Sakaki, Hironao; Yogo, Akifumi; Jinno, Satoshi; Nishiuchi, Mamiko; Matsukawa, Kenya*; Kondo, Kiminori; Oda, Keiji*; Yamauchi, Tomoya*

no journal, , 

In laser-driven ion acceleration experiments using the cluster-gas targets, a significant amount of fast electrons, which drives the ion acceleration, are produced along with high energy ions with several-tens of MeV. Fast electrons could produce high energy photons via bremsstrahlung processes. Accordingly, the photons could produce photo-neutrons via a series of photo-nuclear reactions. In order to diagnose the laser-accelerated protons, we have developed the new analysis technique of CR-39 based on the etch pit geometry, which can practically discriminate the genuine etch pits created by laser-accelerated protons from false etch pits created by the photo-neutrons.

Oral presentation

Laser driven ion acceleration experiment by high contrast high intensity laser J-KAREN system

Nishiuchi, Mamiko; Sakaki, Hironao; Sagisaka, Akito; Maeda, Shota; Pirozhkov, A. S.; Pikuz, T.; Faenov, A. Ya.*; Ogura, Koichi; Fukuda, Yuji; Matsukawa, Kenya*; et al.

no journal, , 

no abstracts in English

Oral presentation

Measurement of electron spectrum generated by irradiating thin-Foil target with Ultra-intense Ultra-short pulse laser

Maeda, Shota; Nishiuchi, Mamiko; Sakaki, Hironao; Sagisaka, Akito; Pirozhkov, A. S.; Pikuz, T.; Faenov, A. Ya.*; Ogura, Koichi; Fukuda, Yuji; Matsukawa, Kenya*; et al.

no journal, , 

In JAEA, the high energy ions generated by the interaction between Ultra-intense Ultra-Short pulse laser and thin-foil target is being studied. Irradiating condition must be optimized to generate higher energy ions while suppress the becoming gigantic of laser. It is necessary to know the physical phenomenon in plasma to determine the parameter to optimize from the information on the electron and neutron, X-rays, which are generated simultaneously with ion. In this study, in order to measure electron temperature accurately, an electron spectrometer was developed which have broad range (1-200 MeV). The detector is comprised of permanent magnets and a fluorescent plate, CCD camera. In the presentation, the result of the calibration experiment carried out using 4, 9, 12, 15 MeV quasi-monoenergetic electron beam in HIBMC will be reported. Moreover, response analysis method was inspected using PHITS which is particle transporting Monte Carlo simulation code, and will also report the result.

Oral presentation

Evaluation of neutron from the laser-driven acceleration

Sakaki, Hironao; Nishiuchi, Mamiko; Maeda, Shota; Sagisaka, Akito; Pirozhkov, A. S.; Pikuz, T.; Faenov, A. Y.*; Ogura, Koichi; Fukuda, Yuji; Matsukawa, Kenya*; et al.

no journal, , 

We report that the results of simultaneous novel measurements of electron-induced photonuclear neutrons (photoneutron), which are a diagnostic of the laser-plasma interaction. The proposed method is demonstrated by the laser irradiation with the intensity of 1$$times$$10$$^{21}$$ W/cm$$^{2}$$ on the metal foil target. The photoneutrons are measured by using NE213 liquid scintillation detectors. The measured signals of the electron-induced photoneutrons are well reproduced by using the Particle and Heavy Ion Transport code System (PHITS).

Oral presentation

Radiation properties of plasma irradiated by ultra-short laser pulses with intensities of 10$$^{21}$$ W/cm$$^{2}$$

Faenov, A.*; Hansen, S.*; Colgan, J.*; Abdallah, J.*; Pikuz, T.; Pikuz, S.*; Skobelev, I.*; Nishiuchi, Mamiko; Sakaki, Hironao; Maeda, Shota; et al.

no journal, , 

Oral presentation

The Possibility of laser-driven heavy ion source

Nishiuchi, Mamiko; Sakaki, Hironao; Nishio, Katsuhisa; Sako, Hiroyuki; Pikuz, T.; Faenov, A. Ya.*; Esirkepov, T. Z.; Pirozhkov, A. S.; Matsukawa, Kenya*; Maeda, Shota; et al.

no journal, , 

The up-grade plan for the heavy ion accelerator facilities in the world is now going on. The important issues to be solved is how to make high-current, high Q/M and high energy heavy ion beam. To make smaller size heavy ion accelerator is important in order to minimize the construction and running costs. The key issue is, "whether or not we can obtain high Q/M ion beam at the very beginning of the accelerator stages". However, the existing conventional ion-source technology can supply the beam of Q/M $$<$$ 0.2. On the other hand, our research at is to accelerate the ions by the laser-based method by using high contrast high intensity short pulse laser system, J-KAREN. Thanks to the extra-ordinary high quasi-static electric field of $$sim$$100 TV/m set in our method, the ions are efficiently stripped and accelerated toward high energy. By optimizing the condition, it is very probable that not only the laser-based ion source but also the laser-based ion injector would be realized. We show the experimental results of high-energy heavy ion acceleration by the interaction between high intensity short-pulse laser pulse interaction with the thin-foil target.

Oral presentation

Laser-driven proton acceleration with a thin-foil target

Sagisaka, Akito; Nishiuchi, Mamiko; Pirozhkov, A. S.; Ogura, Koichi; Sakaki, Hironao; Maeda, Shota; Pikuz, T.; Faenov, A. Y.*; Fukuda, Yuji; Kanasaki, Masato; et al.

no journal, , 

High-intensity laser and thin-foil interactions produce high-energy particles, hard X-ray, high-order harmonics, and terahertz radiation. A proton beam driven by a high-intensity laser has received attention as a compact ion source for medical and other applications. We have performed several high intensity laser-matter interaction experiments using a thin-foil target irradiated by Ti:sapphire laser (J-KAREN) at JAEA. The pulse duration was typically $$sim$$40 fs (FWHM). The high-order harmonics (2nd$$sim$$4th) were observed with the spectrometer in the reflected direction. The maximum proton energy of $$sim$$40 MeV energy were observed at the peak laser intensity of $$sim$$1$$times$$10$$^{21}$$W/cm$$^{2}$$.

Oral presentation

Measurements of the electron temperature from the laser-driven acceleration

Sakaki, Hironao; Nishiuchi, Mamiko; Maeda, Shota; Ishida, Akihiro*; Yamashita, Tomohiro*; Katahira, Kei*; Pikuz, T.; Faenov, A.*; Esirkepov, T. Z.; Pirozhkov, A. S.; et al.

no journal, , 

We will tell about the measurement methods of the electron temperature from the laser-driven acceleration.

Oral presentation

High resolution X-ray spectroscopy of plasma irradiated by ultra-short laser pulses with intensities of 10$$^{21}$$ W/cm$$^{2}$$

Faenov, A.*; Hansen, S. B.*; Colgan, J.*; Abdallah, J.*; Pikuz, T.; Pikuz, S. A.*; Skobelev, I. Y.*; Nishiuchi, Mamiko; Sakaki, Hironao; Maeda, Shota; et al.

no journal, , 

Oral presentation

Multi-charged heavy ion acceleration from the ultra-intense short pulse laser system interacting with the metal target

Nishiuchi, Mamiko; Sakaki, Hironao; Nishio, Katsuhisa; Sako, Hiroyuki; Orlandi, R.; Pikuz, T.; Faenov, A.*; Esirkepov, T. Z.; Pirozhkov, A. S.; Matsukawa, Kenya*; et al.

no journal, , 

To investigate the quark-gruon plasma or the systhesis of the super-heavy elements, the upgrade of the existing large accelerator facilities are going on. At J-PARC, the high flux high energy heavy ion beam is also desired. To have the beam, it is key issue how to obtain the high Q/M heavy ions a the ion source. However, the conventional ion source technique have difficulties to obtain such ions. On the other hand, we succeeded to obtain the high Q/M heavy ion beam with $$>$$ 10 MeV/u from the interaction between the J-KAREN laser and thin foil target interaction. This results shows that the laser-driven ion acceleration scheme have possibility that it can substitute the conventional ion source as well as the injector.

Oral presentation

Laser-driven ion acceleration by high intensity short-pulse high-contrast laser system at JAEA

Nishiuchi, Mamiko; Sakaki, Hironao; Nishio, Katsuhisa; Orlandi, R.; Sako, Hiroyuki; Pikuz, T.; Faenov, A. Ya.*; Esirkepov, T. Z.; Pirozhkov, A. S.; Matsukawa, Kenya*; et al.

no journal, , 

For the applications of compact injector, we conduct the ion acceleration experiments using relatively compact and high-contrast short pulse laser system, J-KAREN at KPSI JAEA. The on-target laser intensity of 10$$^{21}$$ Wcm$$^{-2}$$ with 200TW, less than 10J of energy, is achieved by controlling the temporal and spatial pulse profiles. Without applying plasma mirror system, the maximum proton energy of 43 MeV is obtained with aluminum (Al) 0.8 um thick target. In some shots we observe that the protons and Al ions are accelerated up to 30 MeV and 12 MeV/u, respectively. With the soft X-ray spectroscopy the Al ions are found to be almost fully stripped, which is caused by the synergy of three major effects: optical field ionization due to the laser and plasma collective fields; the electron impact ionization; and the X-ray single photon ionization. The observation of almost fully stripped Al ions proves that laser-driven ions acceleration is a promising ion source for the conventional accelerator. In addition, the observed energy of 12 MeV/u of the Al ions shows that the laser-based ion acceleration method can be the basis of a compact heavy ion injector for nuclear physics.

Oral presentation

Ion acceleration by the 10$$^{21}$$ Wcm$$^{-2}$$ intensity high contrast laser pulses interacting with the thin foil target

Nishiuchi, Mamiko; Sakaki, Hironao; Nishio, Katsuhisa; Orlandi, R.; Sako, Hiroyuki; Pikuz, T.; Faenov, A. Ya.*; Esirkepov, T. Z.; Pirozhkov, A. S.; Matsukawa, Kenya*; et al.

no journal, , 

Laser-driven ion beam is paid attention because of its peculiar characteristics. One of the applications is the compact injector for the conventional accelerator system for the nuclear research. For that objective, we have carried out the J-KAREN experiment with 10$$^{21}$$ Wcm$$^{-2}$$ of intensity, less than 10 J of energy and 35fs of laser duration with 10$$^{10}$$ contrast level. The J-KAREN laser pulses are irradiated on the Al foil target. Almost fully stripped aluminum ion acceleration up to 12 MeV/u from the interaction between the ultra-intense short pulse high contrast laser and the micrometer thick foil target is presented.

23 (Records 1-20 displayed on this page)