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High energy density physics is the field of physics dedicated to the study of matter and plasmas in extreme conditions of temperature, densities and pressures. It encompasses multiple disciplines such as material science, planetary science, laboratory and astrophysical plasma science. For the latter, high energy density states can be accompanied by extreme radiation environments and super-strong magnetic fields. The creation of high energy density states in the laboratory consists in concentrating/depositing large amounts of energy in a reduced mass, typically solid material sample or dense plasma, over a time shorter than the typical timescales of heat conduction and hydrodynamic expansion. Laser-generated, high current–density ion beams constitute an important tool for the creation of high energy density states in the laboratory. Focusing plasma devices, such as cone-targets are necessary in order to focus and direct these intense beams towards the heating sample or dense plasma, while protecting the proton generation foil from the harsh environments typical of an integrated high-power laser experiment. A full understanding of the ion beam dynamics in focusing devices is therefore necessary in order to properly design and interpret the numerous experiments in the field. In this work, we report a detailed investigation of large-scale, kilojoule-class laser-generated ion beam dynamics in focusing devices and we demonstrate that high-brilliance ion beams compress magnetic fields to amplitudes exceeding tens of kilo-Tesla, which in turn play a dominant role in the focusing process, resulting either in a worsening or enhancement of focusing capabilities depending on the target geometry.

Recent progress in the physics of fast ignition of fusion targets is reviewed here. Fundamental studies on hot electron energy transport show that the scheme looks promising if the heating pulse can be guided close enough to a compressed core. The idea of using cone-guided compression was first demonstrated experimentally under a Japan-UK collaboration. The use of the gold cone was extremely successful and showed a 10 3 neutron increase out of CD target implosion with a 300 J/0.5 ps enforced heating laser pulse. The heated temperature was close to 1 keV. In order to increase the temperature to 10 keV, a 10 kJ PW- laser system is necessary. Osaka University has started constructing such a laser system.

Target design and the fabrication scheme are discussed aiming an application for the future laser fusion reactor KOYO-F that has 4 modular chambers with a wet wall operated with fast ignition scheme. Gain estimation and load of fusion output from the non-symetric burn on the first wall are shown.

The progress of laser fusion research at the Institute of Laser Engineering, Osaka University is reviewed. They are physics investigations on target implosion, development of laser technologies, and R&D for laser fusion power plants. The long term strategy of Inertial Fusion Energy (IFE) development has been reexamined taking into account the recent progress of implosion physics and reactor related technologies. 15 refs., 12 figs.

Here we report recent progress for the fast ignition inertial confinement fusion demonstration. The fraction of low energy ( 4% of the heating efficiency and > 4 keV of ion temperature are achievable by using GEKKO-XII and LFEX, properly designed cone-fuel and an external magnetic field.

Recent progresses have shown the possibility of the ignition at the inertial confinement fusion experiment in the direct drive scheme. The imploded core of burning temperature, 5-10 keV, and the imploded core of 600 times liquid fuel density have been realized separately at Osaka University by using less than 10 kJ energy with 3% energy balance. While the high temperature core could only generate the neutrons up to a level of one tenth to a hundredth predicted by the one dimensional calculation at a compression ratio over ten. The required energy and its uniformity on the spherical pellet are trade-off for given the resultant of the implosion. The key issue in the inertial fusion energy development is now the realization of the ignition which is one of milestones to the energy production by the ICF. In this report, the basic design of the Gekko XII upgrade system named {open_quotes}Kongoh{close_quotes} at Osaka University is discussed with system components being developed now to improve the uniformity, controllability, and the energy delivering in the existing building of Gekko XII.

Summary form only given. Intensity nonuniformities in an incident laser beam may cause corresponding variations in the ablation pressure. The variations in the ablation pressure should be less than a few percent in order for spherical targets to implode symmetrically and to be ignited in inertial confinement-fusion experiments. The uniformity requirements on the laser beam could be eased by the degree of lateral heat conduction and plasma-hydrodynamic motions occurring between the absorption and the ablation surfaces. Theoretically, the scaling of the smoothing on the standoff distance (D) between the absorption and the ablation surfaces and the intensity-modulation wavelength (L) is obtained in terms of heat conduction and plasma-fluid motions. Experiments were conducted with a 0.53-/spl mu/m, 1-ns (FWHM), Gaussian shaped laser beam focused onto thin polystyrene targets. The smoothing factor shows a clear exponential decrease as D/L increases.

The fast ignition is a new scheme in laser fusion, in which higher energy gain is expected with smaller laser pulse energy. The cone target has been introduced for realizing higher coupling efficiency. At ILE, Osaka University, the laser with 4 beams and the total output of 10kJ/ps: LFEX has been built and we have started the integrated experiments. The experiments showed that the coupling efficiency is degraded because of the laser pre‐pulse. Namely, the main pulse is absorbed in a long scale pre‐plasma produced by the pre‐pulse and hot electron energy is higher than that for a clean pulse. Furthermore, the distance between the hot electron source and the core plasma is long. So, we are exploring how to overcome the pre‐pulse effects on the cone target. The next series of experiments is planned for this fall. In these experiments, the LFEX pre‐pulse level will be reduced and advanced targets for mitigating the pre‐pulse effects will be introduced.In this paper, it is proposed that a thin foil cover the l...

Thermonuclear ignition and subsequent burn are key physics for achieving laser fusion. In fast ignition, a highly compressed fusion fuel generated with multiple ns‐laser beams is rapidly heated with a large energy, ps‐laser pulse in prior to core disassembly. This scheme has a high potential to achieve ignition and burn since driver energy required for high fusion gain is predicted to be about one tenth of that needed for the central ignition scheme. In Japan, Fast Ignition Realization Experiment (FIREX) project has been started to clarify the physics of energy transport and deposition in the core plasma and to demonstrate fuel temperature of above 5 keV. After the success, FIREX‐I will be followed by the second phase of the project (FIREX‐II) to demonstrate ignition and burn. LFEX laser, designed to deliver a laser pulse of 10 kJ in 10 ps, are operational and the first phase of FIREX experiments has been stated. A new target is proposed to attain dense compression of fuel and improve laser‐core coupling efficiency by adopting double‐cone structure, a low‐density inner liner, low‐Z outer coating, and Br‐doped fuel shell. In this paper, present status and near term prospects of the FIREX‐I project will be reported together with activities on target designing, laser development, and plasma diagnostics.

The kinetic effects of electron heat transport in an imploding plasma are investigated by using the one‐dimensional hydrodynamics implosion code with the Fokker–Planck equation. The Fokker–Planck equation is solved in the implosion simulation by reducing it to the multigroup transport equations. The implosion time, mass ablation rates, and compressed core plasma parameters of the simulations are compared with those of the flux‐limited Spitzer–Harm model simulations and the experimental results of high‐density compression. As a result, it is shown that the Fokker–Planck simulation results agree well with the experiments, in which the random phase plate is employed for the uniform implosion.

Fuel areal density, 〈ρR〉, is a fundamental quantity for ICF implosions. For current and future targets, areal densities are large enough that a variety of neutron based diagnostic techniques can be used to determine fuel 〈ρR〉. These include measurements based on the secondary production of DT neutrons from initially pure deuterium fuel and, for higher 〈ρR〉 values, techniques utilizing high energy tertiary neutrons or lower energy scattered neutrons. This paper describes these techniques and gives an overview of the current experimental status.

The mass ablation rate has been measured using the 12-beam GEKKO XII glass laser. An X-ray pinhole camera coupled to a streak camera was used to provide both spatial and temporal history of the emission from buried maker layers. The camera was filtered by 0.75 mu m of Al to enhance the image of the cool, denser plasma near the ablation front. The targets (diameter approximately 500 mu m) were both polymer shells and solid polymer pellets and were overcoated with up to four maker layers sandwiched between CH ablator layers. Laser energies of up to 8 kJ in 1.7 ns were incident on the targets, with absorbed irradiances of up to 4.0*10/sup 14/ W-cm/sup -2/. Good agreement has been found between the experiment and a one-dimensional hydrodynamic code in which the heat flow is obtained from the Fokker-Planck equation. The mass data were consistent with the temporal behavior of spectral line emissions observed by a streaked crystal spectrography. The introduction of random phase plates had no significant influence on the mass ablation rate for imploding targets. The results indicate that a highly uniform drive pressure has been achieved for the GEKKO XII laser. >

We examined the genomic status of the p16INK4A (inhibitor of cyclin-dependent kinase 4 A) and cyclin-dependent kinase 4 (CDK4) genes in 62 human hepatocellular carcinomas (HCCs), 5 cholangiocellular carcinomas and 6 cell lines derived from human liver cancers. Although no samples showed the homozygous deletion of the p16INK4A gene, we detected intragenic mutations of the p16INK4A gene in 3 HCCs and one HCC cell line, which led to an amino-acid substitution or a frameshift. In 2 HCC samples with mis-sense mutations of the p16INK4A gene, loss of heterozygosity on 9p22 was also detected, suggesting that the loss of function of p16 was induced during hepatocarcinogenesis. On the other hand, amplification or rearrangement of the CDK4 gene was not detected in any samples examined in this study. These results indicated that the mutations or deletions of the p16INK4A gene are not frequent, but may play a role in a sub-set of human HCC.

Nurses provide the psychosocial nursing care to promote the patients' empowerment. In spite of recognizing the importance of psychosocial nursing. The research reported here is part of a large study designed to explore the psychosocial nursing intervention strategies. This part of the study is focused on characteristics of psychosocial nursing care as identified by nurses. Research design was descriptive and qualitative. Subjects were a convenient sample of nurses who have more than 5 years experience and agreed to participate in this research. Data was collected through semistructured interviews. Data was recorded on a tape and transcribed, then analyzed based on Grounded Theory Approach.The number of subjects consisted of 39 nurses. The average age and duration of clinical experience was 36.6 years old and 12.6 years.Sixteen of the characteristics of psychosocial nursing to promote the empowerment among the patients were identified; 1) respect the patients' decision making, 2) clinical judgment from multiple perspectives, 3) predictability, 4) flexibility, 5) classification of the patients by comparison, 6) monitoring, 7) relief from reality, 8) relief from pain and suffering, 9) enhancement of the patients' ego strength, 10) nurture of hope, 11) support individualized daily living styles, 12) encouragement of the patients'own problem solving abilities, 13) respect of individuality, 14) self-utilization, 15) self-control based on professional identity, 16) utilization of team power.Nurses choose from the sixteen dimensions of psychosocial nursing and organizing them in order to stabilizing the patients' conditions.

DD‐produced protons are used to measure the imploded fuel‐shell areal density ρΔR of a cryogenic foam target. 12 green beams of the GEKKO XII laser directly imploded a cryogenic foamshell target containing a liquid or solid D2 fuel. The proton emission is detected through a dipole magnet on a CR‐39 plate, whose energy shift from 3.02 MeV yielded the maximum ρΔR of 12 mg/cm2 or the density of 8 g/cm3, in agreement with that from the secondary neutron method within a factor of 2. The proton energy spread is sensitive to the laser energy imbalance.

Physics investigation of implosion and relevant technology development at ILE, Osaka University are reviewed. Since the completion of GEKKO XII and its first shot in December 1983, high temperature implosion demonstrated 10 keV and 1013 neutron/shot, and high density compressions more than 600 times over initial solid density were achieve. Fundamental physic relevant to the implosion process such as thermal smoothing, R‐T instability, pre‐heat effect and fuel pusher mixing are investigated. Precision GEKKO XII project and fuel capsule development for cryogenic target with preliminary implosion test are going on.Conceptual design of commercial reactor KOYO has been proceeded. LD pump solid state laser is designed showing the feasibility for reactor driver. Fuel pellet design and gain scaling reveals the key physics issues to be investigated in the next step of program. Applications of ICF technologies performed at ILE with outer collaborators are also shown.

The high energetic electron measurement is one of the most important issues to research the ignition mechanism in the Fast Ignition Realization EXperiment Project. It is also important for the energy spectra with angular distribution because the electron spread is different by the target design. Therefore we have been developed the compact Electron SpectroMeter so as to be installed on different angular potions. We have performed the calibration using L-band LINAC in the Institute of Scientific and Industrial Research, Osaka University. The analyzer has been tested to measure energetic electrons from the aluminum and gold plain targets irradiated by LFEX laser (maximum energy of 10 kJ) up to 800 J. The electron measurement has been performed at the integrated experiments using CD-shell with Au cone. The non-Maxwellian spectrum can be observed when the effective core heating by the electron is occurred.

Reported is the simultaneous observations of a beatwave excited plasma wave and energetic electrons. A plasma wave is excited when the beatwave frequency of a laser with 10.6 and 9.57 μm equals the plasma frequency. The Stokes sideband measurement gives the wave amplitude dn/n0 of 5%. Plasma electrons with the energies more than 10 MeV are observed at the resonant density. The experiment offers a possibility for the plasma beatwave accelerator.

The ultrafast imaging methods in sliced sampling streak cameras are investigated. It is shown that the sampling-image x-ray streak camera has potential advantages in highly time-resolved and space-resolved imaging for imploded core plasmas. An optimized sampling method is presented to acquire two-dimensional spatial resolutions ⩽10μm and temporal resolution ∼10ps, within a field of view ∼100μm and a time range ∼100ps.

The fundamental physics and relevant experimental data studied at the Institute of Laser Engineering, Osaka University, are discussed on the subject of laser-wavelength dependence. The main items are (i) absorption, (ii) heat transport and target ablation, (iii) preheating, and (iv) implosion uniformity. Short-wavelength lasers are hopeful candidates for fusion drivers owing to high coupling efficiencies and low preheating.

This paper describes the study of implosion processes of glass microballoon targets irradiated directly and uniformly by the GEKKO XII glass laser system. In this direct driven mode using a high‐aspect‐ratio target, high neutron yields were achieved. Comparison between experiment and the computer simulation using one‐dimensional hydrodynamic codes shows good agreement. Progress of direct driven implosion shows the possibility of achieving breakeven by using the 100 kJ class laser of 0.35 μm wavelength.

High frequency parametric instabilities excited when an intense electromagnetic pulse (ω0, k 0) propagates through an underdense plasma are currently under active investigation.1,2 Energy and momentum conservation give $$ {\omega _{o}} = {\omega _{1}} + {\omega _{2}}$$ and, $$ {\omega _{o}} = {\omega _{1}} + {\omega _{2}} $$ where at least one of the decay waves is an electron plasma wave (epw) with the dispersion relation $$ {\underline k _{o}} = {\underline k _{1}} + {\underline k _{2}} $$ In the underdense corona of a laser fusion pellet there are two such instabilities of particular concern; the two-plasmon decay (2ωp) instability and the stimulated Raman scattering (SRS) instability. This is because the epw’s associated with these instabilities can have phase velocities on the order of the speed of light and therefore produce very energetic electrons when they damp.3 Since such electrons can preheat the fuel in a laser fusion pellet before significant compression the 2ωp and SRS instabilities are of particular concern. In the 2ωp decay instability, the two decay waves are both epw’s so that frequency matching can occur only if ω0 ≃ 2ωp. This instability can therefore be expected to occur only near the quarter-critical layer of an inhomogeneous plasma.