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A simple deuterium DC glow discharge was employed to study the production of densely packed deuterium clusters with high binding energies in palladium. The incident ions create damage cascades leading to the production of defects such as vacancies, dislocations, and voids. These defects trap interstitial deuterons with binding energies dependent on the trap’s geometry and volume. 1 Varying fluences of incident ions were used (1E18 ions/cm 2 , 1E19 ions/cm 2 , and 1E20 ions/cm 2 ) and incident energies dependent on cathode bias (-0.75 kV, -0.875 kV, and -1.0 kV). Thermal Desorption Spectroscopy (TDS) was used to estimate the clusters’ trapping energies. 2 There appeared to be a deuterium trapping limit dependent on defect concentration where once a distinct defect density was met any further damage was counterproductive in deuterium trapping. The condition that produced the most trapped deuterium was -0.75 kV in 1 Torr deuterium with a fluence of 1E18 ions/cm 2 . Some samples were observed under SEM and TEM. The results showed surface pit and blister formations which grew in concentration as the fluence increased. Beneath the surface formations, cross-section images showed large voids and holes in the material with cracks at grain boundaries. TEM images displayed the resulting damage structure which extended ~250 nm into the cathode for a sample at 1.0 Torr and -1.0 kV. A proposal is that as the damage concentration increased, these voids grew to such an extent that they formed the blisters and eventually ruptured.

A coordinated experimental-simulation study was carried out to explore the relationship between plasma conditions and ion angular energy distributions incident on a DC glow discharge cathode. Langmuir probe measurements of the Electron Energy Distribution Functions (EEDF) validated a COMSOL simulation’s accuracy which confirmed the proper methodology for reproducing discharge dynamics. 1 The simulation was a coupling between COMSOL’s Plasma module and Boltzmann Equation, Two-Term Approximation module allowing for accurate calculations of the Townsend coefficients. Proper Townsend coefficients are necessary to represent the kinetics of DC discharges with low ionization fractions and species mobility that are highly dependent on the electric field, e.g., ions transiting the plasma sheath. The EEDFs were measured along the cathode dark space and negative glow regions using the Druyvesteyn method. 2 After the trend of EEDFs were validated, the model was expanded to extract ion angular energy distributions in conditions where measuring plasma properties became no longer feasible.

The importance of the development of chirped pulse amplification (CPA) was highlighted with the award of the 2018 Nobel Prize in Physics to Gerard Mourou and Donna Strickland. CPA laser physics ope...

After achieving significant research results on laser-driven boron fusion, the essential facts are presented how the classical very low-energy gains of the initially known thermal ignition conditions for fusion of hydrogen (H) with the boron isotope 11 (HB11 fusion) were bridged by nine orders of magnitudes in agreement with experiments. This is possible under extreme non-thermal equilibrium conditions for ignition by >10 PW-ps laser pulses of extreme power and nonlinear conditions. This low-temperature clean and low-cost fusion energy generation is in crucial contrast to local thermal equilibrium conditions with the advantage to avoid the difficulties of the usual problems with extremely high temperatures.

For developing a laser boron fusion reactor driven by picosecond laser pulses of more than 30 petawatts power, advances are reported about computations for the plasma block generation by the dielectric explosion of the interaction. Further results are about the direct drive ignition mechanism by a single laser pulse without the problems of spherical irradiation. For the sufficiently large stopping lengths of the generated alpha particles in the plasma results from other projects can be used., 10 pages, 5 figures, extended tex from lectures on 5th and 6th June 2017in Shanghai/China

Pressures created by non-thermal forces from picosecond CPA laser pulses of extreme power can be higher than the hundred million °C temperatures for the usual ignition of fusion of clean and abundant laser boron fusion.

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-thermal pressures can be higher by lasers using nonlinear forces of picoseconds or shorter duration as computer results of 1978 had demonstrated by non-thermal plasma-block acceleration. This is in full agreement with the ultrahigh acceleration measured by Sauerbrey since 1996 thanks to his use of ultra-extreme powers of picosecond CPA-laser pulses. Even the very inefficient classical fusion of hydrogen with the 11B can be used for the non-thermal reaction with sufficiently modest heating in a reactor for generation electricity.

Exceptionally high reaction gains of hydrogen protons measured with the boron isotope 11 are compared with other fusion reactions. This is leading to the conclusion that secondary avalanche reactions are happening and confirming the results of high-gain, neutron-free, clean, safe, low-cost, and long-term available energy. The essential basis is the unusual non-thermal block-ignition scheme with picosecond laser pulses of extremely high powers above the petawatt range.

Evaluation of nuclear binding energies from theory close to available measurements of a very high number of superheavy elements (SHE) based on α-decay energies Q α , arrived at a closing shell with a significant neutron number 184. Within the option of several discussed magic numbers for protons of around 120, Bagge's numbers 126 and 184 fit well and are supported by the element generation measurements by low energy nuclear reactions (LENR) discovered in deuterium loaded host metals. These measurements were showing a Maruhn–Greiner maximum from fission of compound nuclei in an excited state with double magic numbers for mutual confirmation.

Changing the high intensity interaction time of lasers with plasma from nanosecond duration to picoseconds results in a categorically different regime. With high intensity picoseconds laser pulses, the optical energy is converted directly into kinetic energy of plasma blocks without thermal losses, without delays by collisions, and with exclusion of most of the instabilities. Following the long known theory by the nonlinear (ponderomotive) force, the plasma receives a predicted ultrahigh acceleration in agreement with measurements by Sauerbrey. Interaction of the generated plasma blocks with solid state fusion fuel should produce a side-on ignition of a Chu-Bobin fusion flame. Using hydrodynamics with separate electron and ion fluids, detailed properties can be studied about shock generation, including the varying velocity of the flame fronts far . Results from recent computations confirm how the collective nonthermal nonlinear force driven plasma interactions are causing only marginal electron heating.

A fundamental difference of very high intensity laser interaction with plasmas from solid targets appears with lasing at picosecond (ps) pulse durations in contrast to pulses of nanoseconds (ns). This can be seen from the more than 10,000 times higher acceleration with ps pulse durations than with thermal pressure determined interaction. A ps pulse duration produces instantly acting high-efficiency nonlinear (ponderomotive) electrodynamic force dominated acceleration in contrast to heating with longer pulses. The ps pulses accelerate high-density plasma blocks. This can be used by a new scheme of side-on driven laser fusion with generating a flame ignition in uncompressed fusion fuel of solid density resulting in a reaction velocity of more than 2000 km/s for DT.

At very low frequencies, the new pan-European radio telescope LOFAR is opening the last unexplored window of the electromagnetic spectrum for astrophysical studies. The revolutionary APERTIF phased arrays that are about to be installed on the Westerbork radio telescope (WSRT) will dramatically increase the survey speed for the WSRT. Combined surveys with these two facilities will deeply chart the northern sky over almost two decades in radio frequency from \sim 15 up to 1400 MHz. Here we briefly describe some of the capabilities of these new facilities and what radio surveys are planned to study fundamental issues related the formation and evolution of galaxies and clusters of galaxies. In the second part we briefly review some recent observational results directly showing that diffuse radio emission in clusters traces shocks due to cluster mergers. As these diffuse radio sources are relatively bright at low frequencies, LOFAR should be able to detect thousands of such sources up to the epoch of cluster formation. This will allow addressing many question about the origin and evolution of shocks and magnetic fields in clusters. At the end we briefly review some of the first and very preliminary LOFAR results on clusters., Comment: 11 pages, 2 figures, Invited talk at the conference "Diffuse Relativistic Plasmas", Bangalore, 1-4 March 2011; in press for publication in special issue of Journal of Astrophysics and Astronomy

The correlation between radio spectral index and redshift has been exploited to discover high redshift radio galaxies, but its underlying cause is unclear. It is crucial to characterise the particle acceleration and loss mechanisms in high redshift radio galaxies to understand why their radio spectral indices are steeper than their local counterparts. Low frequency information on scales of $\sim$1 arcsec are necessary to determine the internal spectral index variation. In this paper we present the first spatially resolved studies at frequencies below 100 MHz of the $z = 2.4$ radio galaxy 4C 43.15 which was selected based on its ultra-steep spectral index ($\alpha < -1$; $S_{\nu} \sim \nu^{\alpha}$ ) between 365 MHz and 1.4 GHz. Using the International Low Frequency Array (LOFAR) Low Band Antenna we achieve sub-arcsecond imaging resolution at 55 MHz with VLBI techniques. Our study reveals low-frequency radio emission extended along the jet axis, which connects the two lobes. The integrated spectral index for frequencies $, Comment: 14 pages; 9 figures; 4 tables; Accepted for publication in MNRAS

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 petawatt-picosecond laser pulses at anomalous interaction conditions if very high contrast ratio. Updated cross sections of the nuclear reaction are included. In other words, the specific approach discussed here involves inducing a fusion burn wave without radioactivity by laser-driven impact of a relatively large block of plasma on the outside of a solid density H–11B and H–7Li targets.

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)....

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 pulse laser at the Los Alamos National Laboratory (LANL). The corresponding hot spot heating is then calculated using this assumed deuteron beam spectrum. The resulting first order heating dynamics is employed in the expanded “bonus” energy calculation, and a 12.73% extra energy from deuteron beam-target fusion was found with the assumed deuteron spectrum when ρrb = 4.5 g/cm2 is considered, where ρ is the fuel density, and rb is the ion beam focusing radius on the target. The results provide further insight into the contribution of the extra heat produced by deuteron beam-target fusion to the hot spot ignition process. A further analysis of how a converter foil using ultra-high-density cluster materials can help to achieve the yield requirements for ignition is presented.

An extreme anomaly of laser-plasma interaction with petawatt-picosecond (PW-ps) pulses of very high contrast ratio for suppression of relativistic self-focusing permitted a come-back of the Bobin-Chu side-on ignition of uncompressed deuterium-tritium (DT) fusion fuel. The plasma blocks for the side-on ignition have to be produced by the well confirmed nonlinear force acceleration which is about 100,000 times higher than thermo-kinetic fluid-dynamic acceleration for comparison with astrophysical cases. It is essential that the dielectric plasma properties within the nonlinear force are used. Using the measured ion beam densities above 1011 A s/cm2 the ignition mechanism needed numerical and theoretical studies of extremely strong shock phenomena. When extending these results to the side-on ignition of uncompressed hydrogen-boron11 (HB11), surprisingly, the ignition by this shock mechanism was only about 10 times more difficult than for DT in contrast to ignition by spherical laser driven compression using thermo-kinetic conditions in which case HB11 ignition is 100,000 times more difficult than DT.

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 based on volume ignition showed some usual improvements of the fusion gains. However, for a very narrow range of parameters, the increase of the gain was found to be higher by more than a factor 6. This is very unusual in all similar computations and is related to retrograde properties which were known for other parameter values. On top it is most important that the anomalous range is in the practically very interesting range for incorporation of laser pulse energies of few megajoules. The gains of up to 20 may be of interest for power generation in future by the high density fusion scheme.

Protons and neutrons are emitted in many fusion processes of light nuclei. In a fusion reactor, a proton and a neutron thus generated may again fuse with each other. Or they can in turn fuse with or be captured by an un-reacted nuclear fuel, for example deuterium. The average center-of-mass energy for such reaction is around 10 keV in a typical fusion reactor. At this low energy, the reacting nucleons are in an s-wave state in terms of their relative angular momentum. The single-gamma radiation process is thus strongly suppressed due to conservation laws. Instead the gamma ray released is likely to be accompanied by soft X-ray photons from a nuclear bremsstrahlung process. The generated soft X-ray has a continuous spectrum and peaks around a few hundred eV to a few keV. The average photon energy and spectrum properties of such a process are calculated with a semi-classical approach, with the explicit example of proton–neutron capture. This phenomenon may have been observed in some prior tokamak discharge experiments, and its interpretation is complicated by the presence of electron bremsstrahlung. However, it also opens up the possibility of new plasma diagnostics which are more sensitive to the ionic or nuclear degree of freedom.

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 clean laser pulses with better than 108contrast ratio for suppression of relativistic self-focusing. When updating the analysis of Chu for fusion of deuterium-tritium and proton-11B, one problem is that the correct use of the stopping power of the alpha particles had to be solved. Discrepancies are evaluated in view of the stopping power at the low temperature range of the plasmas where the change of the emitted bremsstrahlung is involved.