Heinrich Hora

UNSW Sydney | UNSW · Department of Theoretical Physics

The Prague Asterix Laser System (PALS) is a terawatt iodine laser (1.2 kJ, 350 ps, 1315 nm), designed to deliver irradiance on target of about 3e16 W/cm2. The PALS laser together with a Ti:sapphire laser (1 J, 50 fs, 800 nm) is used for experiments allowing femtosecond probing of laser-produced plasma. We present an experimental study of emission o...

Nuclear reactions produce ten million times more energy than the chemical reactions e.g. from burning carbon, but the equilibrium thermal pressures for chemical reactions need temperatures of hundred °C while nuclear burns need many dozens of million °C. This is on the level for ITER or at NIF with using nanosecond laser pulses. In contrast, non-th...

With the aim to overcome the problems of climatic changes and rising ocean levels, one option is to produce large-scale sustainable energy by nuclear fusion of hydrogen and other very light nuclei similar to the energy source of the sun. Sixty years of worldwide research for the ignition of the heavy hydrogen isotopes deuterium (D) and tritium (T)...

Extreme laser pulses driving non-equilibrium processes in high density plasmas permit an increase of the fusion of hydrogen with the boron isotope 11 by nine orders of magnitude of the energy gains above the classical values. This is the result of initiating the reaction by non-thermal ultrahigh acceleration of plasma blocks by the nonlinear (ponde...

Extreme laser pulses driving non-equilibrium processes in high density plasmas permit an increase of the fusion of hydrogen with the boron isotope 11 by nine orders of magnitude of the energy gains above the classical values. This is the result of initiating the reaction by non-thermal ultrahigh acceleration of plasma blocks by the nonlinear (ponde...

The physics basics of the interaction of lasers with plasmas are presented as before including a fundamental question with Richard Feynman about nonlinearity opening a new chapter of research. New in the second edition are the last 20 years results with extremely short laser pulses and extremely high powers (Peta- to Exawatt and more) including the...

Fusion energy from reacting hydrogen (protons) with the boron isotope 11 (HB11) resulting in three stable helium nuclei, is without problem of nuclear radiation in contrast to DT fusion. But the HB11 reaction driven by nanosecond laser pulses with thermal compression and ignition by lasers is extremely difficult. This changed radically when irradia...

After the very long consideration of the ideal energy source by fusion of the protons of light hydrogen with the boron isotope 11 (boron fusion HB11) the very first two independent measurements of very high reaction gains by lasers basically opens a fundamental breakthrough. The non-thermal plasma block ignition with extremely high power laser puls...

Ultrahigh acceleration of plasma blocks in the range of 1020 cm/s2 has been confirmed experimentally after this was long predicted as a non-thermal direct conversion of optical energy into plasma motion due to dominating nonlinear (ponderomotive) forces [1]. The use of laser pulses of more than PW power and ps or shorter duration can ignite a nucle...

The application of laser pulses with psec or shorter duration enables nonthermal efficient ultrahigh acceleration of plasma blocks with homogeneous high ion energies exceeding ion current densities of $10^{12}~\text{A}~\text{cm}^{-2}$ . The effects of ultrahigh acceleration of plasma blocks with high energy proton beams are proposed for muon produc...

Compared with the deuterium tritium (DT) fusion, the environmentally clean fusion of protons with 11B is extremely difficult. When instead of nanosecond laser pulses for thermal-ablating driven ignition, picosecond pulses are used, a drastic change by nonlinearity results in ultrahigh acceleration of plasma blocks. This radically changes to economi...

Fusion energy from reacting hydrogen (protons) with the boron isotope 11 (HB11) resulting in three stable helium nuclei, is without problem of nuclear radiation in contrast to DT fusion. But the HB11 reaction driven by nanosecond laser pulses with thermal compression and ignition by lasers is extremely difficult. This changed radically when irradia...

The burning process of high density (about 10¹⁸cm⁻³), high temperature (tens to hundreds of keV) plasma trapped by a high mirror-like magnetic field in a Compact Magnetic Fusion (CMF) device is numerically investigated.. The initial high density and high temperature plasma in the CMF device is produced by ultrashort high intensity laser beam intera...

The interaction of the sub-picosecond UV laser in sub-relativistic intensities with deuterium is investigated. At high plasma temperatures, based on the quantum correction in the collision frequency, the electron heating and the ion block generation in plasma are studied. It is found that due to the quantum correction, the electron heating increase...

Erratum to: J. Fusion energy DOI 10.1007/s10894-014-9759-5In the original version of this article, Figs. 2, 3, 4, 5, 7 and 8 need a correction due to an improvement of the computer code. The correct figures and captions are given below. There is no change in the contents of the original version.Fig. 2Solid HB11 cylinder of 5 mm radius irradiated by...

In contrast to the broad stream of sustainable developments on fusion energy, new aspects are developed now by applying ultra-short, ultra-powerful laser pulses in a plasma-block ignition scheme by avoiding the well known difficulties of thermal-pressure instabilities and losses through using electro-dynamic non-thermal energy conversion. A further...

Interaction of a linearly polarized Gaussian laser pulse (at relativistic intensity of 2.0 × 1020 Wcm−2) with a multi-layer foam (as a near critical density target) attached to a solid layer is investigated by using two-dimensional particle-in-cell simulation. It is found that electrons with longitudinal momentum exceeding the free electrons limit...

Propagation of a chirped laser pulse with a circular polarization through an uprising plasma density profile is studied by using 1D-3V particle-in-cell simulation. The laser penetration depth is increased in an overdense plasma compared to an unchirped pulse. The induced transparency due to the laser frequency chirp results in an enhanced heating o...

Fusion reactions of solid density boron-11 with protons after initiation of a fusion flame by very powerful picosecond laser pulses were derived for plane geometry. The problem of lateral energy losses with laser beams was solved by using spherical geometry, where however the gains are limited. The other elimination of losses now available by cylin...

This work is an electronic pre-publication of a book manuscript being under consideration in order to provide information to interested researchers about a review of mechanical forces in plasmas by electro-dynamic fields. Beginning with Kelvin's ponderomotive force of 1845 in electrostatics, the hydrodynamic force in a plasma is linked with quadrat...

The process of energy loss of charged heavy particles in plasma has been discussed taking into consideration photon emissions by electrons of plasma during scattering as is necessitated by quantum electrodynamics. Although the range in general increases with temperature, it is found that the numerical formula of former treatment giving a range as T...

The efficiency of energy release has been calculated here for fusion reactions in inertially confined plasmas of high density. It is found that inclusion of reheat due to absorption of the energetic alphas released by the reactions in the plasma itself predicts higher gains G due to ignition. Including losses by bremsstrahlung and fuel depletion we...

The laser mechanism in a p-type GaAs slab with no junction and a hole concentration higher than 7 x 1018 cm-3 is investigated theoretically for the case that the excited electrons are injected from a gas discharge outside the slab. With such an excitation by slow electrons a lower bound of the current density is calculated from the Schawlow-Townes...

Measurements of the temperature dependence of the photoemission from multi-alkali cathodes down to 77.4 °K are described. The general shape of the measured characteristics is compared with curves obtained by other authors for cathodes of different origin. It is found that the properties of the cathodes depend on the preparation method. In all measu...

Since C. Yamanaka et al. demonstrated that the best fusion gains from laser irradiated pellets result only when central shocks are avoided and an ideal volume compression is achieved, the problems o f the central (spark) ignition with necessary densities of 1000 times the solid state may be overcome. Based on an analytical formula of volume ignitio...

An account is given of measurements relating to the temperature dependence of the photo­emission of muhialkali cathodes at temperatures in the region of 80 °K. These measurements show intensity-dependent and spectrally dependent non-linearities with hysteresis in which pronounced discontinuities of the quantum yield of the photoemission occur up to...

One of the numerous applications of the ICAN laser using the advantage of fiber optics with chirped pulse amplification (CPA), is the scheme of side-on initiation of a nuclear fusion flame in solid density fuel with laser pulses of shorter than picosecond (ps) duration and power in the petawatt (PW) and higher range. The ICAN Fiber optics has speci...

Aiming breakeven for nuclear fusion energy needs a more than 1000 times higher fusion gain. This may be achieved as the anomalously high jump of gains known from the discovery of volume ignition since 1978. This is considered for combination with the present most advanced experiments at the world highest class laser of NIF.

The formulation of the momentum of electromagnetic radiation or photons in media is a historical question. After Peierls discussed all these options, a crucial new value for the dominating dispersion factor σ was derived for non-ionized media with the consequence that an opto-acoustic coupling exists. After the experimental confirmation of the Kapi...

In this research, we presented the application of picosecond terawatt laser pulses for ultrahigh acceleration of plasma blocks for fast ignition of fusion. Ultrahigh acceleration of plasma blocks after irradiation of picosecond laser pulses of around terawatt power in the range of 1020 cm/s2 was discovered by Sauerbrey (1996) as measured by Doppler...

Physics defines the reasons why laser driven ICF by laser pulses of nanosecond duration is basically different from the use of picosecond length. High intensity picoseconds laser pulses transfer energy directly into kinetic energy of plasma blocks without thermal losses, without delays by collisions and with exclusion of most instabilities. Followi...

A fundamental difference between interaction of laser pulses of less than picosecond duration and power in the range of and above Petawatt appears in contrast to pulses of nanosecond duration. This is due to the basic property that the long pulse interaction is based on thermal effects with inefficient delays of chaotic microscopic thermal motion w...

When crossing an electron beam in vacuum with an optical (laser) beam with standing waves, an interaction was redicted known as Kapitz-Dirac effect where the electrons are diffracted at the nodes of the optical field. After the final success of an experiment was reported (Freimund et al. 2001) confirming this classical kind of laser interaction wit...

The initial Kapitza-Dirac effect for crossing energetic electron beams with laser beams had been generalized for quantum modulation of the electrons. The recent developments provide advanced insights with the initial experimental facts, where consequences are leading to results about non-resonant laser interaction with condensed media including non...

A review of research work done in collaboration with Jak Kelly between 1975 and 2012 at the University of New South Wales requires a rather detailed explanation of the subjects covered. These begin with the pioneering work on very high intensity electron beams of energy ranging between 10 and 200 keV as well as ion beams and their defect generation...

Our recent gas loaded nanoparticle experiments are aimed at developing unique power sources in the kW range. Current experiments are in the 1-300 watt range. They are an outgrowth of "lessons learned" from earlier studies of LENR reactions occurring with light water electrolysis of Ni/Pd. Observations (local melting spots, spotty charged particle e...

The new possibility of side-on laser ignition of p-11B with negligible radioactivity encouraged to study the fusion of solid state p-7Li fuel that again turns out to be only about 10 times more difficult than the side-on ignition of solid deuterium-tritium using petawatt-picosecond laser pulses at anomalous interaction conditions if very high contr...

The new candidates for laser fusion energy with minimized radioactivity were presented. The possibility of side-on laser ignition of H–11B with negligible radioactivity encouraged to study the fusion of solid state H–7Li fuel which again turns out to be only about ten times more difficult than the side-on ignition of solid deuterium–tritium using p...

Arguments are discussed on how ion energy measurements from ultra-thin diamond irradiation with 45 fs laser pulses of 26 terawatt power may be related to the ultra-high acceleration of plasma blocks where the significance of the highly efficient direct conversion of laser radiation into mechanical motion of ions or plasma blocks is dominated by non...

A fundamental different mechanism dominates laser interaction with picosecond-terawatt pulses in contrast to the thermal-pressure processes with ns pulses. At ps-interaction, the thermal effects are mostly diminished and the nonlinear (ponderomotive) forces convert laser energy instantly with nearly 100% efficiency into the space charge neutral ele...

We show that the phase velocity in a stationary state of a de Broglie wave can be directly obtained from the probability distribution, i.e. the quantum trajectories, without detailed knowledge of the phase term itself. In other words, the amplitude of a de Broglie wave function describes not only the probability distribution but also the phase velo...

Results on iodine laser production of Ag, Au, Pb, Sn and Ta ions are presented and experiments on their implantation into steel, Al and plastics are compared and discussed. Ions were implanted without additional acceleration into metals to the depth of several hundreds of nanometers, and into plastics to a depths of up to several micrometers.

DOI:https://doi.org/10.1103/PhysRevE.85.039908

The interaction of laser pulses of picosecond duration and terawatt to petawatt power accelerated for the very fast undistorted plasma blocks for deuterium DD or deuterium tritium fast ignition is investigated. Based on the direct and instant conversion of laser energy into mechanical motion by nonlinear (ponderomotive) forces, any thermal pressure...

The hot spot heating process by an assumed deuteron beam is evaluated in order to estimate the contribution of the energy produced by the deuteron beam-target fusion to the heating process. The deuteron beam energy versus the number of deuterons is evaluated through the experimentally achieved proton beam energy distribution using the TRIDENT short...

Low Energy nuclear Reaction (LENR) Cells are a new way to use nano-structured electrodes in power cells to produce nuclear reactions at low temperature (relative to the temperature for hot fusion). While still in the research stage, this promises ultimate development of "green" nuclear powered "batteries", offering remarkable energy densities well...

In addition to the matured "laser inertial fusion energy" with spherical compression and thermal ignition of deuterium-tritium (DT), a very new alternative for the fast ignition scheme may have now been opened by using side-on block ignition aiming beyond the DT-fusion with igniting the neutron-free reaction of proton-boron-11 (p-11 B). Measurement...

A special Fest-Conference was organized at the University of Illinois, Urbana, US, to celebrate the completion of fifty years of distinguished research work conducted by Professor Georg H. Miley. The special Fest-Conference was organized at the university from April 14-15, 2011 where large number of collaborators, associates, and former students ga...

A volumetrically-loaded ultra-high-density deuterium cluster material is described here for use as a deuteron beam source in laser matter interactions. Due to high volumetric loading, the material has potential to provide enough deuteron beam flux for the inertial confinement fusion (ICF) fuel ignition, avoiding depletion problem encountered by cur...

For quiver energies of electrons in a laser field close to the relativistic threshold, the interaction front with a target is stabilized based on relativistic properties against Rayleigh-Taylor instabilities

The design basis for a possible near-term driven subcritical assembly for student labs using a cylindrical Inertial Electrostatic Confinement (IEC) fusion neutron source is described. The rebirth of nuclear fission power is going to require a new generation of training facilities for students. The IEC driven subcritical provides a very versatile fa...

Following our previous presentation of a new three-fold symmetry for derivation of the magic numbers of nuclei based upon a quark state model of nuclei, here the nuclear binding energy is obtained from such new perspective. From this point of view, since each nucleon is made of three quarks, the binding energy of nuclei contains a volume term propo...

An anomalously strong increase of nuclear fusion gains for laser driven compression and thermal ignition of hydrogen-boron11 has been discovered from computations by using the latest results of Newins and Swain about details of a resonance maximum of the astrophysical S-function at 148 keV for the reaction cross-sections. Extensive computations bas...

The 9th International Workshop on Laser Interaction and Related Plasma Phenomena was held from 6 to 10 November 1989, at Naval Postgraduate School, Monterey, California. This series of meetings began in 1969 and it is the longest series of meetings in this field in the USA. It is, in fact, the longest series with published proceedings that document...

The International Workshop on Laser Interactions and Related Plasma Phenomena is the oldest continuing series of meetings in the United States with published proceedings documenting much of the growth of this dynamic field. The meeting format is designed to provide an interactive atmosphere that encourages first disclosures along with in-depth crit...

The 7th International Workshop in the series Laser Interaction and Related Plasma Phenomena continued the high standards established by the earlier meetings in this series. It was organized under the directorship of Heinrich Hora and George H. Miley at the Naval Postgraduate School in Monterey, California, with Fred Schwirzke as the local organizer...

The refractive index n and the absorption constant K are numerically evaluated for fully ionized hydrogen plasmas as functions of the electron temperature T and atomic density N for the case of ruby, neodymium-glass, and CO2 laser radiation and for the second harmonics of each type of radiation on the basis of the two-fluid model of hydrodynamics u...

Studies of laser produced pair production are followed up from early stages. Pair production by vacuum polarization was discussed with laser produced acceleration up to values similar to those at the surface of black holes leading to the discovery of a difference between Hawking and Unruh radiation. It was found that production of anti-hydrogen by...

An alternative fast ignition scheme with petawatt(PW)-picosecond(ps) laser pulses for producing a fusion flame was based on the fact that the nonlinear force can accelerate plasma blocks by 1020cm/s2 as predicted and measured. These plasma blocks are studied for side- on ignition by the updated Chu-Bobin fusion scheme and permits side-on ignition o...

Specific studies were performed in order to increase the thickness of laser generated directed space charge quasineutral plasma blocks with anomalously high ion current densities above 1011 A/cm2. This may lead to an alternative scheme of laser driven fusion with the irradiation of petawatt-picosecond laser pulses. Initial electron densities were u...

In contrast to laser fusion with spherical plasma compression to very high densities, the alternative was studied with side-on ignition of solid state (or modestly higher) deuterium-tritium, based on hydrodynamic theory. The extremely difficult conditions may be overcome using petawatt-picosecond (PW-ps) laser pulses, however, only by applying the...

Use of laser-driven Inertial Confinement Fusion (ICF) for space propulsion has been examined in several earlier conceptual design studies. However, these designs used older ICF target technology. Important new directions opened following the development of "chirped" lasers capable of ultra-short ps pulses with powers of PWs. This allows fast igniti...

The advent of ultra-high power lasers allows laser power levels that are about 1000 times the power of all the power stations in the USA. This opens the way to new approaches for inertial confinement fusions (ICF) that in turn can drastically reduce the laser input energy needed to achieve practical ICF power. The specific approach discussed here i...

In contrast to the usual laser fusion scheme with spherical irradiation and very high compression and ignition of fuel, the alternative scheme with side-on ignition of uncompressed solid density of fuel (Chu) may lead to a solution by using the now available picosecond laser pulses with higher than petawatt power. A necessary condition is to use cl...

Here we report on the production of highly directed ion blocks by plasma interaction of ultraviolet wavelength light produced from a KrF laser. This may support the requirement to produce a fast ignition deuterium-tritium fusion at densities not much higher than the solid state by a single shot petawatt-picoseconds ultraviolet laser pulse. Using do...

A new three-fold symmetry is presented for derivation of the magic numbers of nuclei and is compared with the model based on the Boltzmann distribution from the standard abundance distribution (SAD) of nuclei in the universe in the endothermic branch. This results in a 3n relation leading to the motivation to explore the quark state in nuclei. But...

Anomalous interaction of terawatt-picosecond laser pulses allows side-on ignition of solid state density fusion fuel with the unexpected possibility of igniting uncompressed hydrogen–boron p-11B. Suppression of relativistic self-focusing by using very clean laser pulses with an extremely high contrast ratio is essential to achieve ignition threshol...

A resurgence in nuclear power use is now underway worldwide. However, due many university research reactors shutdown, they must rely on using sub-critical assemblies which employs a cylindrical Inertial Electrostatic Confinement (IEC) device to provide a fusion neutron source. The source is inserted in a fuel element position, with its power input...

Clusters of condensed deuterium of densities up to 10 29 cm 23 in pores in solid oxide crystals were confirmed from time-of-flight mass spectrometry measurements. Based on these facts, a schematic outline and possible conclusions of expectable generalizations are presented, which may lead to a simplification of laser driven fusion energy including...

Energy production by laser driven fusion energy is highly matured by spherical compression and ignition of deuterium-tritium (DT) fuel. An alternative scheme is the fast ignition where petawatt (PW)-picosecond (ps) laser pulses are used. A significant anomaly was measured and theoretically analyzed with very clean PW-ps laser pulses for avoiding re...

Block ignition was proposed recently as a possible alternate approach to fast ignition for ICF fusion. This approach uses a modified petawatt-picosecond (PW-ps) laser pulse shape where the prepulse is strongly suppressed. This results in highly directed plasma blocks due to nonlinear (ponderomotive) force acceleration with space charge neutral ion...

Anomalous interaction of picosecond laser pulses of terawatt to petawatt power is due to suppression of relativistic self-focusing if prepulses are cut-off by a contrast ratio higher than 10 8 , resulting in quasi-neutral directed plasma blocks with deuterium tritium ion current densities above 10 11 A/cm 2 . This is still not high enough for ignit...

Controlled fusion energy from burning hydrogen with boron-11 is of interest because no neutrons are produced. Following the scheme of ignition by spherical irradiation by laser or particle beams, one has to deal with exorbitant conditions of densities and input energies. A new approach following the scheme of block ignition with laser pulses of pic...

The anomaly at laser plasma interaction at laser pulses of TW to PW power and ps duration led to a very unique generation of quasi-neutral plasma blocks by a skin layer interaction avoiding the relativistic self-focusing. This is in contrast to numerous usual experiments. The plasma blocks have ion current densities above 1011 A/cm2 and may be used...

The use of laser‐driven Inertial Confinement Fusion (ICF) for space propulsion has been the subject of several earlier conceptual design studies, (see: Orth, 1998; and other references therein). However, these studies were based on older ICF technology using either “direct “or “in‐direct x‐ray driven” type target irradiation. Important new directio...

Measurements of thermal conduction in tokamaks parallel to the magnetic field were up to 20 times less than the classical values. This was explained by the quantum correction of the collision frequency of electrons with ions. This stowing effect of heat is applied to re-evaluate the ignition threshold for the energy flux density E* for the ignition...

Measurement of extremely new phenomena during the interaction of laser pulses with terawatt and higher power and picoseconds with plasmas arrived at drastically different anomalies in contrast to the usual observations if the laser pulses were very clean with a contrast ratio higher than 108. This was guaranteed by the suppression of prepulses duri...

A research paper presented focuses on the Maruhn Greiner Maximum of uranium fission for confirmation of low energy nuclear reactions LENR through a compound nucleus with double magic numbers. The paper states that the deuterium ions are space charge neutral until a diameter of 2 to 3 pm, due to the screening factor 13, which is 2.6 times higher tha...

A study was conducted to demonstrate the diagnostics of creation and decay of B-mesons in the Large Hadron Collider (LHC) by using petawatt laser pulses of picosecond duration. The study found that the fine structure of the time dependence and the degree of dependence of the polarization direction of the decay products can be detected by the accele...

A new threefold symmetry is presented for derivation of the magic numbers of nuclei and compared with the model based on the Boltzmann distribution from the standard abundance distribution of nuclei in the universe in the endothermic branch. This results in a 3n relation leading to the motivation to explore the quark state in nuclei. But, this is i...

Hydrodynamic analysis for ignition of inertial fusion by Chu [Phys. Fluids 15, 413 (1972)] arrived at extremely high thresholds of a minimum energy flux density E* at 4×108 J/cm2 which could be provided, e.g., by spark ignition. In view of alternative schemes of fast ignition, a re-evaluation of the early analysis including later discovered collec...