共查询到20条相似文献,搜索用时 31 毫秒
1.
主要给出了“闪光二号”加速器高功率离子束(HPIB)产生及应用研究的初步结果.介绍了强箍缩反射离子束二极管的结构及工作原理,给出了考虑阴阳极产生的等离子体运动对二极管间隙影响的饱和顺位流修正公式.实验得到的离子束峰值能量约500keV,峰值电流约160kA.介绍了利用高功率离子束(质子束)轰击19F靶产生6—7MeV准单能脉冲γ射线的初步实验结果,给出了利用高功率脉冲离子束模拟1keV黑体辐射x射线对材料的热-力学效应初步研究结果.
关键词:
高功率离子束
箍缩二极管
准单能脉冲γ射线
热-力学效应 相似文献
2.
An oscillator-amplifier XeCl laser system has been used to experimentally investigate the effectiveness of a liquid stimulated Brillouin scattering (SBS) mirror for correcting the spatial aberrations of broad-band laser radiation in a double-pass amplifier. It has been found that the SBS amplifier performance is strongly dependent on the intensity I
p exciting the Brillouin medium. A good beam reconstruction has been attained at I
p1GW/cm2, whereas highly aberrated output beams have been delivered by the SBS amplifier for I
p>1 GW/cm2. By comparing the broad-band SBS amplifier performance to that of the same amplifier with a dielectrically coated flat mirror at one end, it has been found that the use of a SBS mirror is advantageous to obtain lower divergence output beams only for low energy pump beams (<1 mJ). 相似文献
3.
《Physics letters. A》1988,131(1):73-77
New results on mixing in single layered metal structures exposed to nanosecond high power ion beams (HPIB) are presented. Au/Cu and Cu/Mo structures have been investigated using RBS, SIMS, AES and transmission electron microscopy. It is shown that HPIB-induced mixing was initiated at the substrate-deposited-layer interface in contrast to laser melting which starts at the surface. Cu3Au superstructure phase, CuAu metastable state and an amorphous structure have been revealed. Cu/Mo structures which cannot produce equilibrium alloys and compounds and strongly differ in their thermophysical properties, can be mixed in the gaseous and liquid phases by three HPIB pulses with 0.95 J/cm2 energy density. 相似文献
4.
A new mechanism of destruction of transparent dielectrics with small highly-absorbing inclusions by using intensive laser emission has been suggested. It has been shown that for experimentally found values of threshold radiation intensity Ith ≈ 1 GW/cm2 and impurity concentration n ? 107 cm-3 radiation absorption outside the front of the impurity-initiated shock wave, when allowing for the collective action of waves, results in great heating of the dielectric surface layer which causes its destruction. The found critical value of impurity concentration is several orders less than the value estimated over a model of heating of an inclusion-surrounding dielectric at the expense of heat conductivity. 相似文献
5.
A. Picciotto L. Torrisi S. Gammino A. M. Mezzasalma F. Caridi D. Margarone 《辐射效应与固体损伤》2013,168(10-12):705-713
The temperature of laser-generated pulsed plasmas is an important property that depends on many parameters, such as the particle species and the time elapsed from the laser interaction with the matter and the surface characteristics. Laser-generated plasmas with low intensity (<1010 W/cm2) at INFN-LNS of Catania and with high intensity (>1014 W/cm2) in PALS laboratory in Prague have been investigated in terms of temperatures relative to ions, electrons, and neutral species. Time-of-flight (ToF) measurements have been performed with an electrostatic ion energy analyzer (IEA) and with different Faraday cups, in order to measure the ion and electron average velocities. The IEA was also used to measure the ion energy, the ion charge state, and the ion energy distribution. The Maxwell–Boltzmann function permitted to fit the experimental data and to extrapolate the ion temperature of the plasma core. The velocity of the neutrals was measured with a special mass quadrupole spectrometer. The Nd:Yag laser operating at low intensity produced an ion temperature core of the order of 400 eV and a neutral temperature of the order of 100 eV for many ablated materials. The ToF of electrons indicates the presence of hot electron emission with an energy of ~1 keV. 相似文献
6.
7.
H. Minami D. Manage Y.Y. Tsui R. Fedosejevs M. Malac R. Egerton 《Applied Physics A: Materials Science & Processing》2001,73(5):531-534
We have compared the quality of carbon films deposited with magnetically guided pulsed laser deposition (MGPLD) and conventional
pulsed laser deposition (PLD). In MGPLD, a curved magnetic field is used to guide the plasma but not the neutral species to
the substrate to deposit the films while, in conventional PLD, the film is deposited with a mixture of ions, neutral species
and clusters. A KrF laser pulse (248 nm) was focused to intensities of 10 GW/cm2 on a carbon source target and a magnetic field strength of 0.3 T was used to steer the plasma around a curved arc to the
deposition substrate. Electron energy loss spectroscopy was used in order to measure the fraction of sp3 bonding in the films produced. It is shown that the sp3 fraction, and hence the diamond-like character of the films, increased when deposited only with the pure ion component by
MGPLD compared with films produced by the conventional PLD technique. The dependence of film quality on the laser intensity
is also discussed.
Received: 7 December 2000 / Accepted: 20 August 2001 / Published online: 2 October 2001 相似文献
8.
V. S. Kovivchak T. V. Panova 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2016,10(6):1226-1230
The influence of a high-power ion beam on polycrystalline oxides (V2O5, MoO3, and WO3) is investigated. Oxide irradiation with ion beams with current densities of greater than ~30 A/cm2 is established to initiate changes in the color of irradiated layers and lead to surface-layer particle melting. It is demonstrated that a distinctive feature of the interaction between a high-power ion beam and V2O5 is the formation of surface nanosheets and nanowires whose characteristic cross-sectional size and thickness are ~1 μm and up to ~40 nm, respectively. The nanosheets are generated near emerging surface cracks if the beam current density is ~100 A/cm2. Possible mechanisms of surface nanostructures formation under the action of pulsed ion beams are discussed. 相似文献
9.
10.
V. A. Gribkov A. V. Dubrovsky M. Paduch M. J. Sadowski M. Scholz K. Tomaszewski K. Malinowski E. Skladnik-Sadowska P. Strzyzewski A. K. Marchenko A. V. Tsarenko S. A. Masljaev V. N. Pimenov 《Czechoslovak Journal of Physics》2006,56(12):1401-1416
The paper presents results of recent experiments, as performed with the PF-1000 and PF-6 Plasma-Focus facilities, which were
aimed at investigation of the correlation between processes of the irradiation of different materials of fusion devices and
results of this irradiation. Among the irradiated samples there were pure tungsten, tantalum, copper, aluminum, and alloys,
based on these metals, various steels, carbon and carbon-based materials, which are designed for plasma facing components
or constructional parts of future thermonuclear reactors of the inertial- and magnetic-confinement types. The corpuscular
radiation consisted of high-energy (E
D>100 keV) deuterium ion beams and fast (v
str ≥ 107 cm/s) deuterium-plasma streams. They were investigated by a number of methods with spatial and temporal resolution. Particular
attention was paid to the verification of diagnostic techniques, which might be used for time- and space-resolved studies
of the interaction process. Correlation of these data with information obtained from subsequent analytical investigation of
some of the irradiated specimens, as performed by means of a number of methods typical for material sciences, gives possibility
to deduce physical mechanisms of the deuterium implantation and radiation damage of the investigated materials in dependence
on the conditions of their irradiation. 相似文献
11.
12.
H. Hora 《Optical and Quantum Electronics》1970,2(4):201-214
Ruby laser intensities exceedingI
* - 1014 W/cm2 create a predominant acceleration of dense plasma due to nonlinear collisionless interaction resulting mainly from collective effects. Recoil causes confinement of the plasma interior in the form of a superlinearly increased radiation pressure. Similar nonlinear forces produce self-focusing in plasmas at a threshold laser power of only 105 to 106 W. The resulting filaments have intensitiesI
*, from which their diameter can be determined in agreement with measurements of Korobkin and Alcock. These high intensities should allow some observed properties of laser produced plasmas (keV ions, linear increase of the ion charge) to be interpreted on the basis of the nonlinear acceleration described. 相似文献
13.
N. G. Basov B. L. Vasin A. A. Galichii A. E. Danilov B. Yu. Ivanov M. P. Kalashnikov B. V. Kruglov Yu. A. Mikhailov V. P. Osetrov V. N. Puzyrev A. V. Rode S. M. Savchenko G. V. Sklizkov V. M. Solodkov S. I. Fedotov V. A. Tsitovich L. I. Shishkina 《Journal of Russian Laser Research》1983,4(3):205-220
The construction principle and the applicable system are considered for the highpower laser amplifier module of the “Del'fin” facility, intended for spherical heating of thermonuclear targets. Results are presented of investigations of the radiation parameters of the amplifier module under various operating regimes. The system for focusing the laser radiation on the target surfaces is described and the results of experiments on plasma heating by radiation of three composite laser beams, at a laser energy level up to 1 kJ at a flux density up to 1014 W/cm2, are analyzed. 相似文献
14.
V. S. Kovivchak T. V. Panova O. V. Krivozubov N. N. Leontieva E. V. Knyazev 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2014,8(2):351-355
The modification of polycrystalline oxides (SnO2 and ZnO) under the action of a nanosecond high-power ion beam (HPIB) with current densities of 50–150 A/cm2, which is accompanied by melting of initial particles of the surface layer, is investigated. It is established that submicron-sized particles of tetragonal SnO whose average size is 210 nm are formed on the SnO2 surface irradiated by an ion beam with a current density of 150 A/cm2. These particles have pronounced crystallographic faceting. When ZnO is irradiated by HPIBs with different current densities, a thin Zn film is formed in the sintered surface layer. Possible mechanisms of the observed conversions are discussed. 相似文献
15.
G. E. Remnev Yu. F. Ivanov E. P. Naiden M. S. Saltymakov A. V. Stepanov V. F. Shtan’ko 《Technical Physics》2009,54(4):600-602
Synthesis of silicon carbide and diamond nanoparticles is studied during short-pulse implantation of carbon ions and protons
into a silicon target. The experiments are carried out using a TEMP source of pulsed powerful ion beams based on a magnetically
insulated diode with radial magnetic field B
r
. The beam parameters are as follows: the ion energy is 300 keV, the pulse duration is 80 ns, the beam consists of carbon
ions and protons, and the ion current density is 30 A/cm2. Single-crystal silicon wafers serve as a target. SiC nanoparticles and nanodiamonds form in the surface layer of silicon
subjected to more than 100 pulses. The average coherent domain sizes in the SiC particles and nanodiamonds are 12–16 and 8–9
nm, respectively. 相似文献
16.
This paper presents an investigation of the resonant excitation of the electrostatic ion cyclotron wave at the difference frequency of two microwave beams propagating in a magnetoactive solid state plasma, viz. n InSb. The resonant excitation of the electrostatic ion cyclotron wave occurs when the difference frequency of the two microwave beams and the difference of their propagation vectors satisfy the dispersion relation corresponding to the electrostatic ion cyclotron wave. For typical plasma parameters of n InSb and microwave beams of power densities 1 MW cm?2, the power density of the excited ion cyclotron wave is 0.40 kW cm?2 when external magnetic field is . The power density of the excited ion cyclotron wave increases with the magnetic field. This study may provide new means for the characterisation and diagnostic of semiconductors. 相似文献
17.
T. Redel J. Eberlein R. Tkotz W. Hartmann M. Stetter R. Stark K. Frank J. Christiansen 《Applied Physics A: Materials Science & Processing》1992,54(6):520-522
The investigation of the interaction of pulsed electron beams with PMMA (polymethylmethacrylate) targets is reported. The electron beam of some 10–8 s in duration is produced in a pulsed low-pressure gas discharge. The beam power density of up to 108 W/cm2 leads to a surface plasma formation similar to that of the pulsed laser ablation process. The propagation of the ablated material and the shock wave inside the PMMA target are observed by means of Schlieren diagnostics. An electron density gradient of over 3×1019 cm–4 has been observed in the expanding plasma up to 1.5 s after the plasma formation. During the early stage of expansion, the expansion velocity of the plasma plume as determined by the steep electron density gradient is around 105 cm/s. The pressure behind the shock front inside the PMMA target as determined from the shock velocity exceeds 0.3 Gpa. 相似文献
18.
M. Borghesi T. Toncian J. Fuchs C. A. Cecchetti L. Romagnani S. Kar K. Quinn B. Ramakrishna P. A. Wilson P. Antici P. Audebert E. Brambrink A. Pipahl R. Jung M. Amin O. Willi R. J. Clarke M. Notley P. Mora T. Grismayer E. D’Humières Y. Sentoku 《The European physical journal. Special topics》2009,175(1):105-110
The acceleration of high-energy ion beams following the interaction of short (t < 1 ps) and intense (Iλ2 > 1018 W cm-2 μm2) laser pulses with solid targets is a field of research currently attracting high interest in the scientific community, due
to some of the unique properties of these ion sources, promising routes toward the optimization of their energy content, and
a number of possible, innovative applications in the scientific, technological and medical areas. Work on the characterization
and development of these sources has progressed enormously over the past few years, thanks to the contribution of many groups
worldwide. This paper will report some recent results, obtained in experiments carried out at the RAL and LULI laboratories,
in which we investigated the ion acceleration mechanism, developed a technique to control the ion beam divergence and energy
spectrum, and applied a proton radiography technique to investigate electric and magnetic field production following laser-matter
interaction. 相似文献
19.
P. Mathey S. Latour P. Lompré P. Jullien D. Rytz B. Salce 《Applied physics. B, Lasers and optics》2000,71(4):523-531
The temperature distribution in a parallelepipedic crystal irradiated with a Gaussian repartition of light is calculated by
solving the three-dimensional heat equation and taking into account the losses through the sides of the samples. The theoretical
and experimental maps of temperature are satisfactorily compared. For barium titanate crystals, the resistance to intense
cw laser (25.7 kW/mm2 at 514.5 nm) and to Nd:YAG pulsed laser (peak power of 9.2 MW at 532 nm) is investigated. The defects induced by the irradiation
are analysed. Under pulsed illumination, the damage threshold is found to be 0.54 GW/cm2 in a nominally undoped BaTiO3 and 0.44 GW/cm2 in a rhodium-cobalt doped BaTiO3 crystal.
Received: 7 March 2000 / Revised version: 14 April 2000 / Published online: 16 August 2000 相似文献
20.
Voitsekhovskii A. V. Kokhanenko A. P. Shul'ga S. A. Smith R. 《Russian Physics Journal》2003,46(8):791-799
A mathematical model for describing the interaction between high-power pulsed ion beams and semiconductor CdxHg1–x
Te (cadmium–mercury–tellurium or CMT) targets is developed, the results of numerical simulation are reported, and the comparison with experiment is performed. 相似文献