Laser-driven acceleration of ion beams for ion fast ignition: the effect of the laser wavelength on the ion beam properties

AbstractFast ignition of inertial fusion targets driven by quasi-monoenergetic ion beams is investigated by means of numerical simulations. Light and intermediate ions such as lithium, carbon, aluminum and vanadium have been considered. Simulations show that the minimum ignition energies of an ideal configuration of compressed Deuterium-Tritium are almost independent on the ion atomic number. However, they are obtained for increasing ion energies, which scale, approximately, as Z2, where Z is the ion atomic number. Assuming that the ion beam can be focused into 10 µm spots, a new irradiation scheme is proposed to reduce the ignition energies. The combination of intermediate Z ions, such as 5.5 GeV vanadium, and the new irradiation scheme allows a reduction of the number of ions required for ignition by, roughly, three orders of magnitude when compared with the standard proton fast ignition scheme.

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Preparation of TEM samples by focused ion beams

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100138968 ◽

1995 ◽

Vol 53 ◽

pp. 518-519

Author(s):

John F. Walker ◽

J C Reiner ◽

C Solenthaler

Keyword(s):

Integrated Circuit ◽

Polycrystalline Silicon ◽

Field Effect Transistor ◽

High Spatial Resolution ◽

Ion Beam ◽

Ion Beams ◽

Focused Ion Beams ◽

Precise Location ◽

Effect Transistor ◽

Circuit Technology

The high spatial resolution available from TEM can be used with great advantage in the field of microelectronics to identify problems associated with the continually shrinking geometries of integrated circuit technology. In many cases the location of the problem can be the most problematic element of sample preparation. Focused ion beams (FIB) have previously been used to prepare TEM specimens, but not including using the ion beam imaging capabilities to locate a buried feature of interest. Here we describe how a defect has been located using the ability of a FIB to both mill a section and to search for a defect whose precise location is unknown. The defect is known from electrical leakage measurements to be a break in the gate oxide of a field effect transistor. The gate is a square of polycrystalline silicon, approximately 1μm×1μm, on a silicon dioxide barrier which is about 17nm thick. The break in the oxide can occur anywhere within that square and is expected to be less than 100nm in diameter.

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Atomic force microscopy (AFM) of the topography of silicon surfaces exposed to ion beams

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100130298 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1132-1133

Author(s):

Mark Denker ◽

Jennifer Wall ◽

Mark Ray ◽

Richard Linton

Keyword(s):

Secondary Ion Mass Spectrometry ◽

Incidence Angle ◽

Ion Beam ◽

Depth Profiling ◽

Depth Resolution ◽

Ion Beams ◽

Scanning Tunneling ◽

Tunneling Microscopy ◽

Trace Impurities ◽

Energy Dose

Reactive ion beams such as O2+ and Cs+ are used in Secondary Ion Mass Spectrometry (SIMS) to analyze solids for trace impurities. Primary beam properties such as energy, dose, and incidence angle can be systematically varied to optimize depth resolution versus sensitivity tradeoffs for a given SIMS depth profiling application. However, it is generally observed that the sputtering process causes surface roughening, typically represented by nanometer-sized features such as cones, pits, pyramids, and ripples. A roughened surface will degrade the depth resolution of the SIMS data. The purpose of this study is to examine the relationship of the roughness of the surface to the primary ion beam energy, dose, and incidence angle. AFM offers the ability to quantitatively probe this surface roughness. For the initial investigations, the sample chosen was <100> silicon, and the ion beam was O2+.Work to date by other researchers typically employed Scanning Tunneling Microscopy (STM) to probe the surface topography.

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Chemical Precursors for GaAs Etching with low Energy ion Beams: Chlorine adsorption on GaAs(100)

MRS Proceedings ◽

10.1557/proc-223-215 ◽

1991 ◽

Vol 223 ◽

Cited By ~ 3

Author(s):

Richard B. Jackman ◽

Glenn C. Tyrrell ◽

Duncan Marshall ◽

Catherine L. French ◽

John S. Foord

Keyword(s):

Ion Beam ◽

Ion Beams ◽

Low Energy ◽

Ion Beam Etching ◽

Chlorine Adsorption

ABSTRACTThis paper addresses the issue of chlorine adsorption on GaAs(100) with respect to the mechanisms of thermal and ion-enhanced etching. The use of halogenated precursors eg. dichloroethane is also discussed in regard to chemically assisted ion beam etching (CAIBE).

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Yttrium Oxide Freeze-Casts: Target Materials for Radioactive Ion Beams

Materials ◽

10.3390/ma14112864 ◽

2021 ◽

Vol 14 (11) ◽

pp. 2864

Author(s):

Eva Kröll ◽

Miriana Vadalà ◽

Juliana Schell ◽

Simon Stegemann ◽

Jochen Ballof ◽

...

Keyword(s):

Pore Structure ◽

Yttrium Oxide ◽

Ion Beam ◽

Isotope Separation ◽

Target Material ◽

Ion Beams ◽

Radioactive Isotopes ◽

Solid Loading ◽

Radioactive Ion Beams ◽

Freeze Casting

Highly porous yttrium oxide is fabricated as ion beam target material in order to produce radioactive ion beams via the Isotope Separation On Line (ISOL) method. Freeze casting allows the formation of an aligned pore structure in these target materials to improve the isotope release. Aqueous suspensions containing a solid loading of 10, 15, and 20 vol% were solidified with a unidirectional freeze-casting setup. The pore size and pore structure of the yttrium oxide freeze-casts are highly affected by the amount of solid loading. The porosity ranges from 72 to 84% and the crosslinking between the aligned channels increases with increasing solid loading. Thermal aging of the final target materials shows that an operation temperature of 1400 °C for 96 h has no significant effect on the microstructure. Thermo-mechanical calculation results, based on a FLUKA simulation, are compared to measured compressive strength and forecast the mechanical integrity of the target materials during operation. Even though they were developed for the particular purpose of the production of short-lived radioactive isotopes, the yttria freeze-cast scaffolds can serve multiple other purposes, such as catalyst support frameworks or high-temperature fume filters.

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Production of ion beams in high-power laser–plasma interactions and their applications

Laser and Particle Beams ◽

10.1017/s0263034604221048 ◽

2004 ◽

Vol 22 (1) ◽

pp. 19-24 ◽

Cited By ~ 21

Author(s):

F. PEGORARO ◽

S. ATZENI ◽

M. BORGHESI ◽

S. BULANOV ◽

T. ESIRKEPOV ◽

...

Keyword(s):

Laser Pulse ◽

Medical Physics ◽

Ion Beam ◽

Laser Pulses ◽

Ion Beams ◽

Laser Plasma Interactions ◽

Physical Mechanisms ◽

Short Laser Pulses ◽

Laser Pulse Intensity ◽

Target Design

Energetic ion beams are produced during the interaction of ultrahigh-intensity, short laser pulses with plasmas. These laser-produced ion beams have important applications ranging from the fast ignition of thermonuclear targets to proton imaging, deep proton lithography, medical physics, and injectors for conventional accelerators. Although the basic physical mechanisms of ion beam generation in the plasma produced by the laser pulse interaction with the target are common to all these applications, each application requires a specific optimization of the ion beam properties, that is, an appropriate choice of the target design and of the laser pulse intensity, shape, and duration.

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Applications of Energy Beams in Material and Device Processing

MRS Proceedings ◽

10.1557/proc-23-25 ◽

1983 ◽

Vol 23 ◽

Author(s):

G.J. Galvin ◽

L.S. Hung ◽

J.W. Mayer ◽

M. Nastasi

Keyword(s):

Ion Beam ◽

High Energy ◽

Ion Beams ◽

Traditional Role ◽

Near Surface ◽

Device Processing ◽

Composition Modification ◽

Directed Energy ◽

Transistor Fabrication

ABSTRACTEnergetic ion beams used outside the traditional role of ion implantation are considered for semiconductor applications involving interface modification for self-aligned silicide contacts, composition modification for formation of buried oxide layers in Si on insulator structures and reduced disorder in high energy ion beam annealing for buried collectors in transistor fabrication. In metals, aside from their use in modification of the composition of near surface regions, energetic ion beams are being investigated for structural modification in crystalline to amorphous transitions. Pulsed beams of photons and electrons are used as directed energy sources in rapid solidification. Here, we consider the role of temperature gradients and impurities in epitaxial growth of silicon.

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Surface Analysis by MeV Ion Beams and Microscopy

Microscopy and Microanalysis ◽

10.1017/s1431927609990894 ◽

2009 ◽

Vol 15 (S3) ◽

pp. 87-88

Author(s):

José A. R. Pacheco de Carvalho ◽

Cláudia F. F. P. R. Pacheco ◽

António D. Reis

Keyword(s):

Surface Analysis ◽

Nuclear Reactions ◽

Ion Beam ◽

Ion Beams ◽

Analysis Method ◽

Analysis Techniques ◽

Target Composition ◽

Nuclear Techniques ◽

Surface Analysis Techniques ◽

Wide Range

AbstractMaterial analysis, specially surface analysis of materials, has been increasingly important. A wide range of surface analysis techniques is available. The techniques are, generally, complementary. There are nuclear and non-nuclear techniques, e.g. microscopy. Nuclear techniques, which are nondestructive, permit analysis for a few microns near the surface. They have been applied to areas such as scientific, technologic, industry, arts and medicine, using MeV ion beams. Nuclear reactions permit to achieve high sensitivities for detection of light elements in heavy substrates and also discrimination of isotopes. We use ion-ion nuclear reactions, elastic scattering and the energy analysis method, where an energy spectrum is obtained of ions from the target for a chosen energy of the incident ion beam. The target composition and concentration profile information contained in the spectrum is computationally obtained through a computer program that has been developed for predicting such energy spectra. Predicted spectra obtained for variations of target parameters are compared with experimental data, giving that information. SEM and TEM are also used.

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FIB Precise Prototyping and Simulation

MRS Proceedings ◽

10.1557/proc-0960-n10-03-ll06-03 ◽

2006 ◽

Vol 960 ◽

Cited By ~ 3

Author(s):

Philipp M. Nellen ◽

Victor Callegari ◽

Juergen Hofmann ◽

Elmar Platzgummer ◽

Christof Klein

Keyword(s):

High Precision ◽

Ion Beam ◽

Ion Beams ◽

Focused Ion Beams ◽

Fresnel Lenses ◽

Closed Approach ◽

Physical Effects

ABSTRACTWe present a closed approach towards direct microstructuring and high precision prototyping with focused ion beams (FIB). The approach uses the simulation of the involved physical effects and the modeling of geometry/topography during milling while the ion beam is steered over the surface. Experimental examples are given including the milling of single spots, trenches, rectangles, and Fresnel lenses. Good agreements between simulations and experiments were obtained. The developed procedures can also be applied to other FIB prototyping examples.

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