A review of low density porous materials used in laser plasma experiments

Abstract

This review describes and categorizes the synthesis and properties of low density porous materials, which are commonly referred to as foams and are utilized for laser plasma experiments. By focusing a high-power laser on a small target composed of these materials, high energy and density states can be produced. In the past decade or so, various new target fabrication techniques have been developed by many laboratories that use high energy lasers and consequently, many publications and reviews followed these developments. However, the emphasis so far has been on targets that did not utilize low density porous materials. This review therefore, attempts to redress this balance and endeavors to review low density materials used in laser plasma experiments in recent years. The emphasis of this review will be on aspects of low density materials that are of relevance to high energy laser plasma experiments. Aspects of low density materials such as densities, elemental compositions, macroscopic structures, nanostructures, and characterization of these materials will be covered. Also, there will be a brief mention of how these aspects affect the results in laser plasma experiments and the constrictions that these requirements put on the fabrication of low density materials relevant to this field. This review is written from the chemists' point of view to aid physicists and the new comers to this field.

High-flux high-energy ion beam production from stable collisionless shock acceleration by intense petawatt-picosecond laser pulses

“…The target combining the near critical plasmas and the high density tube is complicated. However, as the rapid and significant technological advances have been made in the target fabrication [57], the target described in this paper can now or very soon be manufactured, where the tube can be filled with foams [38], cryogenic hydrogen microjet [39] or high-pressure gas jets [40]. In order to make the proposed scheme work properly without prematurely expansion of the tube wall, a laser contrast of 10 10 is required, which is available by using the plasma mirrors [58,59].…”

“…Second, similarly, a large number of hot electrons disperse transversely into a much broader area outside the laser focal spot without recirculation, which results in severe reduction of plasma temperature as well as shock velocity, and eventually inefficient reflection/acceleration of ions. Note that the near-critical plasma is now available via either using foams [38], cryogenic hydrogen microjet target [39], high-pressure gas jets [40] or exploding an ultrathin foil with nanosecond lasers [41]. We also notice that, very recently, a experiment using high-intensity 1 μm wavelength laser have successfully demonstrated the ability of CSA to efficiently accelerate ions with high yield and narrow distributions [42], where the ion energy (15-20 MeV) and particle number (3×10 9 ) in a 10 % energy width is comparable to the best results obtained experimentally by any other mechanism, including TNSA.…”

Silica Mesoporous Structures: Effective Nanocarriers in Drug Delivery and Nanocatalysts

“…These properties are determined by their shape [2], size [3], and composition. Compared to uniform particles of the same size, porous nanomaterials have unique properties due to their vacant spaces, including low densities [4][5][6][7], large active surfaces [8][9][10], low refractive coefficients [11][12][13][14], desirable permeabilities [15][16][17], good selectivity [18][19][20], and thermal and acoustic resistances [21][22][23]. The above-mentioned characteristics of porous nanostructures have resulted in the presentation of diverse nanoporous materials, which have attracted the attention of scientists in a variety of fields.…”

Easy-handling minimum mass laser target scaffold based on sub-millimeter air bubble -An example of laser plasma extreme ultraviolet generation-

“…Low density materials are versatile; used in many applications such as tissue engineering 3 , high surface area matrix 4 , and widely throughout laser plasma experiments. Within laser plasma experiments, critical electron density of plasma is a key parameter to determine the absorption of laser resulting high energy density state, generating of quantum beam 5,6 . Ultralow density less than the critical density, typically ~1 mg/cm 3 , is desired to control the plasma character 7,8 .…”

“…For example, Gd (6 nm) is of interest as a beyond EUV source 43,44 , which can be found in nanoparticle form. A detailed review on general uses, including surface coatings, of microcapusles have been discussed elsewhere 5 .…”