Angular distributions of ions from laser-produced plasma

This paper presents comprehensive experimental results of angular distributions of ions emitted from laser-produced plasmas. Performing a series of laser shots onto planar Sn, Au, and Pb targets, both the focusing conditions as well as the tilt angle of the target were changed to study the effect on the plasma expansion. In the experiments, the iodine laser system PERUN (laser energy of 30 J in 350 ps of duration) with laser power density of 5 × 1014 W/cm2 was used. For plasma diagnostics four ion collectors and an ion-energy analyzer were applied. Comparison of angular distribution of the fast ion group (velocity within the range of 1–3.4 × 108 cm/s) and of the slow ion group (velocity within the range of 0.14–1 × 108 cm/s) shows distinct differences. The preferred direction of ion emission of these groups depends seriously on focusing conditions. When setting the focus on the in-focus position both groups of ions are peaked in the direction close to the target normal. The maximum charge of ions registered by the ion-energy analyzer were 36+, 51+, and 49+ for Sn, Au, and Pb, respectively.

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Protons and ion acceleration from thick targets at 1010 W/cm2 laser pulse intensity

Laser and Particle Beams ◽

10.1017/s0263034610000728 ◽

2010 ◽

Vol 29 (1) ◽

pp. 29-37 ◽

Cited By ~ 20

Author(s):

L. Torrisi ◽

F. Caridi ◽

L. Giuffrida

Keyword(s):

Laser Pulse ◽

Relative Yield ◽

Ion Acceleration ◽

Energy Analyzer ◽

Ion Energy ◽

Laser Absorption ◽

Pulse Intensity ◽

Laser Pulse Intensity ◽

Emission Yield ◽

Ion Emission

AbstractProton ion acceleration via laser-generated plasma is investigated at relatively low laser pulse intensity, on the order of 1010 W/cm2. Time-of-flight technique is employed to measure the ion energy and the relative yield. An ion collector and an ion energy analyzer are used with this aim and to distinguish the number of charge states of the produced ions. The kinetic energy and the emission yield are measured through a consolidated theory, which assumes that the ion emission follows the Coulomb-Boltzmann-Shifted function. The proton stream is generated by thin and thick hydrogenated targets and it is dependent on the free electron states, which increase the laser absorption coefficient and the ion acceleration. The maximum proton energy, of about 200 eV, and the maximum proton amount can be obtained with thick metallic hydrogenated materials, such as the titanium hydrate TiH2.

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Angular distributions of ions emitted from laser plasma produced at various irradiation angles and laser intensities

Laser and Particle Beams ◽

10.1017/s0263034608000591 ◽

2008 ◽

Vol 26 (4) ◽

pp. 555-565 ◽

Cited By ~ 26

Author(s):

L. Láska ◽

K. Jungwirth ◽

J. Krása ◽

E. Krouský ◽

M. Pfeifer ◽

...

Keyword(s):

Laser Beam ◽

Angular Distributions ◽

Linear Interaction ◽

Preferred Direction ◽

Self Focusing ◽

Laser Focus ◽

Ponderomotive Forces ◽

Irradiation Geometry ◽

Irradiation Angle ◽

Ion Emission

AbstractAngular distributions of currents and velocities (energies) of ions produced at various target irradiation angles and laser intensities ranged from 1010 W/cm2 to 1017 W/cm2 were analyzed. It was confirmed that for low laser intensities the ion current distributions are always peaked along the target normal. However, at laser intensities comparable to or higher than 1014 W/cm2, the preferred direction of ion emission strongly depends on the irradiation geometry (laser focus setting, the irradiation angle), and can be off the target normal. This is very likely caused by the non-linear interaction of the laser beam with produced plasma, in particular, by the action of ponderomotive forces and the laser beam self-focusing.

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Multiply charged ions from iodine laser-produced plasma of medium- and high-Z targets

Laser and Particle Beams ◽

10.1017/s026303460001171x ◽

1998 ◽

Vol 16 (1) ◽

pp. 5-12 ◽

Cited By ~ 17

Author(s):

J. Krása ◽

L. Láska ◽

K. Mašek ◽

M. Pfeifer ◽

B. Králiková ◽

...

Keyword(s):

Laser System ◽

General View ◽

Ion Energy ◽

Iodine Laser ◽

Maximum Charge ◽

Multiply Charged ◽

Laser Produced Plasma ◽

Current Densities ◽

Charged Ions ◽

Ion Species

Maximum charge states of ions registered in the far expansion zone from laser-produced plasma of Al, Co, Ni, Cu, Ta, W, Pt, Au, Pb, and Bi are presented. The Thomson parabola spectrometer was used to display a general view of the ion species of an expanding plasma while detailed ion charge-energy spectra were determined by the cylindrical electrostatic ion energy analyzer. The current densities of highly charged ion groups above 20 mA/cm2 were measured by use of an ion collector at a distance of ∼1 m from the target. The photodissociation iodine laser system PERUN (λ = 1.315 μm, power density up to ∼1015 W cm−2) was employed as a driver.

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Corpuscular diagnostics and processing methods applied in investigations of laser-produced plasma as a source of highly ionized ions

Laser and Particle Beams ◽

10.1017/s0263034600010053 ◽

1996 ◽

Vol 14 (3) ◽

pp. 293-321 ◽

Cited By ~ 202

Author(s):

E. Woryna ◽

P. Parys ◽

J. Wołowski ◽

W. Mróz†

Keyword(s):

Experimental Data ◽

Electron Emission ◽

Secondary Electron ◽

Neutral Atom ◽

Secondary Electron Emission ◽

Energy Analyzer ◽

Ion Energy ◽

Laser Produced Plasma ◽

Corpuscular Diagnostics ◽

Ion Emission

This paper presents a set of complementary corpuscular diagnostics applied in experiments for investigation of laser-produced plasma as a source of ions. The measuring possibilities and methods for processing experimental data of a cylindrical electrostatic ion energy analyzer, a Thomson parabola ion analyzer, various types of electrostatic probes, a detector of neutral atom fluxes, as well as methods for visualization of ion emission areas are discussed. Special attention was focused on the ion-induced secondary electron emission problem and its influence on the accuracy of the measurements.

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Fast ion emission from the plasma produced by the PALS laser system

Plasma Physics and Controlled Fusion ◽

10.1088/0741-3335/44/7/316 ◽

2002 ◽

Vol 44 (7) ◽

pp. 1277-1283 ◽

Cited By ~ 34

Author(s):

J Wolowski ◽

J Badziak ◽

F P Boody ◽

H Hora ◽

V Hnatowicz ◽

...

Keyword(s):

Laser System ◽

Ion Emission ◽

Fast Ion

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X-ray and ion emission studies from subnanosecond laser-irradiated SiO2 aerogel foam targets

Laser and Particle Beams ◽

10.1017/s0263034617000489 ◽

2017 ◽

Vol 35 (3) ◽

pp. 505-512 ◽

Cited By ~ 2

Author(s):

C. Kaur ◽

S. Chaurasia ◽

A.A. Pisal ◽

A.K. Rossall ◽

D.S. Munda ◽

...

Keyword(s):

Laser Energy ◽

Laser System ◽

Line Emission ◽

Plasma Temperature ◽

X Rays ◽

Plasma Parameters ◽

X Ray ◽

Spectral Ranges ◽

Ion Emission

AbstractIn this experiment, a comparative study of ion and X-ray emission from both a SiO2 aerogel foam and a quartz target is performed. The experiment is performed using Nd:glass laser system operated at laser energy up to 15 J with a pulse duration of 500 ps with focusable intensity of 1013–1014 W/cm2 on target. X-ray fluxes in different spectral ranges (soft and hard) are measured by using X-ray diodes covered with Al filters of thickness 5 µm (0.9–1.56 keV) and 20 µm (3.4–16 keV). A 2.5 times enhancement in soft X-ray flux (0.9–1.56 keV) and a decrease of 1.8 times in hard X rays (3.4–16 keV) for 50 mg/cc SiO2 aerogel foam is observed compared with the solid quartz. A decrease in the flux of the K-shell line emission spectrum of soft X rays is noticed in the case of the foam targets. The high-resolution K-shell spectra (He-like) of Si ions in both the cases are analyzed for the determination of plasma parameters by comparing with FLYCHK simulations. The estimated plasma temperature and density are Tc = 180 eV, ne = 7 × 1020 cm−3 and Tc = 190 eV, ne = 4 × 1020 cm−3 for quartz and SiO2 aerogel foam, respectively. To measure the evolution of the plasma moving away from the targets, four identical ion collectors are placed at different angles (22.5, 30, 45, and 67.5°) from target normal. The angular distribution of the thermal ions are scaled as cosnθ with respect to target normal, where n = 3.8 and 4.8 for the foam and quartz, respectively. The experimental plasma volume measured from the ion collectors and shadowgraphy images are verified by a two-dimensional Eulerian radiative–hydrodynamic simulation (POLLUX code).

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Angular Distribution and Ion Time of Flight Produced on Silicon Target by Laser Irradiation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.227.31 ◽

2011 ◽

Vol 227 ◽

pp. 31-34

Author(s):

Yasmina Belaroussi ◽

Tahar Kerdja ◽

Smail Malek

Keyword(s):

Angular Distribution ◽

Laser Energy ◽

Angular Distributions ◽

Physical Processes ◽

Incident Laser ◽

Ion Energy ◽

Incident Laser Energy ◽

Silicon Target ◽

The Mean

The growth of thin films by laser ablation involves very complex physical processes. The quality of the layer and stoechiometry of the deposits depend on key parameters like the ion energy and their angular distribution. The evolution of ions number and energy, and the angular distributions in regards to the incident laser energy, have been studied by the mean of a charges collector. We present the polar diagrams of energy and number of ions collected by irradiating a silicon target using an excimer laser at different energies.

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Enhanced laser ion acceleration from mass-limited targets

Laser and Particle Beams ◽

10.1017/s0263034608000268 ◽

2008 ◽

Vol 26 (2) ◽

pp. 225-234 ◽

Cited By ~ 50

Author(s):

J. Limpouch ◽

J. Psikal ◽

A.A. Andreev ◽

K. YU. Platonov ◽

S. Kawata

Keyword(s):

Laser Energy ◽

Ion Acceleration ◽

Acceleration Process ◽

Beam Diameter ◽

Hot Electron ◽

Laser Beam Diameter ◽

Ion Energy ◽

Particle In Cell ◽

Geometrical Form ◽

Fast Ion

AbstractLaser interactions with mass-limited targets are studied here via numerical simulations using our relativistic electromagnetic two-dimensional particle-in cell code including all three-velocity components. Analytical estimates are derived to clarify the simulation results. Mass-limited targets preclude the undesirable spread of the absorbed laser energy out of the interaction zone. Mass-limited targets, such as droplets, are shown here to enhance the achievable fast ion energy significantly due to an increase in the hot electron concentration. For given target dimensions, the existence is demonstrated for an optimum laser beam diameter when ion acceleration is efficient and geometrical energy losses are still acceptable. Ion energy also depends on the target geometrical form and rounded targets are found to enhance the energy of accelerated ions. The acceleration process is accompanied by generation of the dipole radiation in addition to the ordinary scattering of the electromagnetic wave.

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Multiply charged ion emission from laser produced tungsten plasma

Laser and Particle Beams ◽

10.1017/s0263034612000687 ◽

2012 ◽

Vol 30 (4) ◽

pp. 651-657 ◽

Cited By ~ 10

Author(s):

B. Ilyas ◽

A.H. Dogar ◽

S. Ullah ◽

N. Mahmood ◽

A. Qayyum

Keyword(s):

Charge State ◽

Laser Fluence ◽

Experimental Studies ◽

Clear Correlation ◽

Threshold Fluence ◽

Energy Analyzer ◽

Plume Expansion ◽

Ion Energy ◽

Expansion Model ◽

Ion Emission

AbstractPlasma was generated by focusing 10 ns Nd:YAG (λ = 1064 nm) laser pulse on the thick tungsten target. The laser fluence at the target was varied in the range of 3.57–10.97 J/cm2. The ion emission from the expanding tungsten plasma was analyzed with the help of an ion collector and time-of-flight electrostatic ion energy analyzer. About 44 times rise in the ion charge per laser shot was observed in the investigated laser fluence range. The measured threshold fluence for onset of the tungsten plasma was 3.27 J/cm2. The estimated plume expansion coefficient Zinf/Xinf = 2.5 ± 0.2 was in agreement with the previous experimental studies and the predictions of self-similar plume expansion model. The electrostatic ion energy analyzer study showed that charge state of the W ions increases with the laser fluence and maximum ion charge state was 5+. It was observed that threshold fluence for appearance of a specific charge state can be measured. A clear correlation between the relative abundances of W(n−1)+, Wn+, and W(n+1)+ indicates that higher order charge states are most probably produced by stepwise ionization process.

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