The application of intense ion beams to the creation of hot dense plasmas

A broad review is presented of the physics central to the production of hot dense plasmas by intense ion beams. Particular attention is paid to the reasons for using ion beams rather than lasers. By using simple laws the required beam intensities and ion energies for light ions (protons, deuterons, etc.) and heavy ions ( A > 120) are compared. Current understanding of ion-dense plasma interactions is discussed together with current thinking on possible accelerator sources of intense beams and their final transport to small targets. Emphasis is placed throughout on the use of ion beams for heating targets of deuterium-tritium mixtures to thermonuclear ignition.

2014 ◽  
Vol 508 ◽  
pp. 012006 ◽  
Author(s):  
J Badziak ◽  
S Jabloński ◽  
T Pisarczyk ◽  
T Chodukowski ◽  
P Parys ◽  
...  
Keyword(s):  

Author(s):  
Qiang Sun ◽  
Qianhong Zhou ◽  
Hantian Zhang ◽  
Wei Yang ◽  
Ye Dong ◽  
...  

Abstract The separation phenomenon of light and heavy ions was widely observed experimentally in the vacuum arc discharge with multi-component composite cathode. In this work, a two-dimensional axisymmetric multi-fluid model is used to study the separation mechanism in the multi-component composite cathode vacuum arc. The multi-component vacuum arcs are simulated as a whole which includes separate cathode spot jets, the mixing region, and common arc column. The results show that the plasma jets originated from the separate cathode spot mix together to form a common arc column after a certain distance from the cathode. Due to the rapid increase of ion temperature dozens of times in mixing region of cathode spot jet, the effect of pressure gradient becomes far greater than that of the collisions between light and heavy ions. This leads to a shift in the predominant ion motion mechanism from ion-ion collision (single cathode spot jet region) to pressure expansion (the mixing region). Finally, the light ions gain higher velocities under pressure expansion. In addition, the effect of thermal conductivity and viscosity leads to the wider high temperature regions for light ions, thus making a wider distribution of corresponding ion flux. The numerical results are qualitatively consistent with the experimental results. This paper provides an insight into ion separation mechanism in the multi-component vacuum arc.


Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1309
Author(s):  
Marcel Miglierini

Due to their excellent magnetic properties, amorphous metallic alloys (AMAs) are considered for the construction of magnetic cores of radio-frequency cavities in accelerators. Here, they might be exposed to ion bombardment. The influence of irradiation by both light and heavy ions featuring low and high energies, respectively, is followed by the techniques of 57Fe Mössbauer spectrometry. Modifications of surface layers in selected Fe-containing AMAs after ion irradiation are unveiled by detection of conversion electrons and photons of characteristic radiation whereas those in their bulk are derived from standard transmission spectra. Rearrangement of microstructure which favors the formation of magnetically active regions, is observed in surface regions bombarded by light ions. Heavy ions caused pronounced effects in the orientation of net magnetization of the irradiated samples. No measurable impact upon short-range order arrangement was observed. Part I of this paper is devoted to radiation effects in Fe-based AMAs induced by neutron irradiation.


1981 ◽  
Vol 52 (5) ◽  
pp. 3269-3275 ◽  
Author(s):  
G. Gerdin ◽  
W. Stygar ◽  
F. Venneri

1997 ◽  
Vol 31 (2) ◽  
pp. 169-174 ◽  
Author(s):  
C. Stöckl ◽  
M. Roth ◽  
W. Süß ◽  
H. Wetzler ◽  
W. Seelig ◽  
...  
Keyword(s):  

2019 ◽  
Vol 37 (4) ◽  
pp. 549-559 ◽  
Author(s):  
Andrei Y. Malykhin ◽  
Elena E. Grigorenko ◽  
Elena A. Kronberg ◽  
Patrick W. Daly ◽  
Ludmila V. Kozak

Abstract. In this work we present an analysis of the dynamics of suprathermal ions of different masses (H+, He+, O+) during prolonged dipolarizations in the near-Earth magnetotail (X>-17RE) according to Cluster/RAPID observations in 2001–2005. All dipolarizations from our database were associated with fast flow braking and consisted of multiple dipolarization fronts (DFs). We found statistically that fluxes of suprathermal ions started to increase ∼1 min before the dipolarization onset and continued to grow for ∼1 min after the onset. The start of flux growth coincided with the beginning of a decrease in the spectral index γ. The decrease in γ was observed for protons for ∼1 min after the dipolarization onset, and for He+ and O+ ions for ∼3 and ∼5 min after the onset respectively. The negative variations of γ for O+ ions were ∼2.5 times larger than for light ions. This demonstrates more efficient acceleration for heavy ions. The strong negative variations of γ were observed in finite energy ranges for all ion components. This indicates the possibility of nonadiabatic resonant acceleration of ions in the course of their interaction with multiple DFs during dipolarizations. Our analysis showed that some fraction of light ions can be accelerated up to energies ≥600 keV and some fraction of oxygen ions can be accelerated up to ∼1.2 MeV. Such strong energy gains cannot be explained by acceleration at a single propagating DF and suggest the possibility of multistage ion acceleration in the course of their interaction with multiple DFs during the prolonged dipolarizations.


2009 ◽  
Vol 75 (1) ◽  
pp. 15-18 ◽  
Author(s):  
P. K. SHUKLA

AbstractThe excitation of electrostatic ion wakefields by electromagnetic pulses in a very dense plasma is considered. For this purpose, a wave equation for the ion wakefield in the presence of the ponderomotive force of the electromagnetic waves is obtained. Choosing a typical profile for the electromagnetic pulse, the form of the ion wakefields is deduced. The electromagnetic wave-generated ion wakefields can trap protons and accelerate them to high energies in dense plasmas.


1967 ◽  
Vol 45 (12) ◽  
pp. 4039-4051 ◽  
Author(s):  
L. Hastings ◽  
A. van Wijngaarden

Local regions on the surface of ZnO:Zn phosphor samples were deteriorated by a large number of low-energy ions. In this manner thin films which did not luminesce under ion bombardment were prepared. The phosphor samples were then scanned across energetic ion beams with sufficient energy to traverse the thin phosphor films. By comparing the luminescent response to this ion excitation in the damaged and undamaged portions of the phosphor surface, the total average energy losses of 1H, 4He, 14N, 40Ar, and 84Kr in passing through the films were determined. It was found that the energy losses for the heavier projectiles, when compared with the energy loss of hydrogen, are appreciably smaller than the energy losses predicted by the Lindhard and Scharff theory.The deterioration depth of the phosphor under prolonged bombardment is proportional to the speed of the damaging projectiles.


2004 ◽  
Vol 22 (1) ◽  
pp. 25-28 ◽  
Author(s):  
O. RENNER ◽  
I. USCHMANN ◽  
E. FÖRSTER

Modern experimental methods and instruments for X-ray spectral investigation of hot dense plasma provide complex information on environmental conditions in extreme states of matter. The basic spectroscopic conceptions for K-shell plasma diagnosis are outlined, the main characteristics of toroidally bent crystal spectrometers and vertical-dispersion instruments are briefly reviewed. Selected applications (monitoring and optimization of the emission from the femtosecond-laser-produced plasmas, characterization of colliding laser-exploded foils, spectral line merging, and continuum lowering in constrained-flow plasmas) demonstrate the usefulness of advanced spectroscopic methods for plasma diagnostics and fundamental research.


1998 ◽  
Vol 16 (1) ◽  
pp. 21-30 ◽  
Author(s):  
P. Angelo ◽  
H. Derfoul ◽  
P. Gauthier ◽  
P. Sauvan ◽  
A. Poquerusse ◽  
...  

We create hot (Te > 200 eV) and dense (Ne > 1023 cm−3) plasmas in the colliding zone of two thin foils accelerated by two laser beams of the LULI facilities. Three spectroscopic diagnostics (two 1D space-resolved spectrographs and a 2D monochromatic imaging) are used to drive the efficiency of the compression. We show that 2D effects are important. Realistic simulations of these experiments must be done, taking into account the inhomogeneity of the laser intensity in the focal spot, the foil distorsion, the plasma lateral expansion, and the lateral thermal conduction. Two-dimensional LASNEX code results are in good agreement with our experimental results. The optimized compressed plasmas generated are favorable for the exhibition of dense plasma effects due to molecular formations, and they reproduce in laboratory some astrophysical situations.


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