Leif Holmlid

Ultrahigh-density deuterium of Rydberg matter clusters for inertial confinement fusion targets

Clusters of condensed deuterium of densities up to 10 29 cm −3 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 new techniques for preparation of targets for application in experiments of the NIF type, but also for modified fast igniter experiments using proton or electron beams or side-on ignition of low compressed solid fusion fuel.

Stability and excitation of potassium promoter in iron catalysts – the role of KFeO2 and KAlO2 phases

Well‐characterized catalyst model compounds of KAlO2 and KFeO2 are investigated by thermal desorption of potassium from the material. The desorbing fluxes of ions, atoms and highly excited states (field ionizable Rydberg states) were studied with surface and field ionization detectors in a vacuum apparatus. From the Arrhenius plots the activation energies for desorption of K and K+ were determined. The chemical state of potassium at the surfaces is concluded to be: ionic on KAlO2 (with the K desorption barrier of 1.76 eV) and covalent on KFeO2 (barrier of 2.73 eV). These results agree with the data obtained earlier for industrial catalysts for ammonia and styrene production. They are interpreted in terms of the Schottky cycle, which is completed for KAlO2 and fails for KFeO2. This failure indicates a non‐equilibrium desorption process. K Rydberg states are only found to desorb from KFeO2, in agreement with the suggestion that such states in some way are responsible for the catalytic activity.

Rydberg Matter clusters of hydrogen (H2)N∗ with well-defined kinetic energy release observed by neutral time-of-flight

Abstract Neutral Rydberg Matter clusters of hydrogen ( H 2 ) N ∗ are studied using laser fragmentation neutral time-of-flight measurements outside a K impregnated iron oxide emitter in ultrahigh vacuum. A ns pulsed dye laser beam passing in front of the emitter releases the clusters by Coulomb explosions in the Rydberg Matter cloud surrounding the emitter. Well-resolved cluster peaks are observed, and the kinetic temperature of the clusters is low and well described by T/N, where T is the emitter temperature and N is the number of H2 molecules in the cluster. The clusters are neutral as verified by applying a negative voltage of a few V to the emitter, with no change in the flight times. The clusters receive a common excess kinetic energy of ⩽1 eV in the Coulomb explosions initiated by the laser pulse. The common excess kinetic energy shows that the clusters come from larger clusters or clouds with a large inertia. The sharp time-of-flight peaks show that the bonds in the Rydberg Matter broken by the laser are in just one specific quantum number state, n=3–7. The observed excess energy increases with laser intensity, and the fragmentation pattern changes simultaneously.

Efficient source for the production of ultradense deuterium D(-1) for laser-induced fusion (ICF)

A novel source which simplifies the study of ultradense deuterium D(-1) is now described. This means one step further toward deuterium fusion energy production. The source uses internal gas feed and D(-1) can now be studied without time-of-flight spectral overlap from the related dense phase D(1). The main aim here is to understand the material production parameters, and thus a relatively weak laser with focused intensity ≤10(12) W cm(-2) is employed for analyzing the D(-1) material. The properties of the D(-1) material at the source are studied as a function of laser focus position outside the emitter, deuterium gas feed, laser pulse repetition frequency and laser power, and temperature of the source. These parameters influence the D(-1) cluster size, the ionization mode, and the laser fragmentation patterns.

Laser-induced variable pulse-power TOF-MS and neutral time-of-flight studies of ultradense deuterium

The ultradense atomic deuterium material named D(−1) is conveniently studied by laser-induced Coulomb explosion methods. A well-defined high kinetic energy release (KER) from this material was first reported in Badiei et al (2009 Int. J. Hydrog. Energy 34 487) and a two-detector setup was used to prove the high KER and the complex fragmentation patterns in Badiei et al (2009 Int. J. Mass Spectrom. 282 70). The common KER is 630 ±30 eV, which corresponds to an interatomic distance D–D of 2.3 ±0.1 pm. In both ion and neutral time-of-flight (TOF) measurement, two similar detectors at widely different flight distances prove that atomic particles are observed. New results on neutral TOF spectra are now reported for the material D(−1). It is shown that density changes of D(−1) are coupled to similar changes in ordinary dense D(1), and it is proposed that these two forms of dense deuterium are rapidly transformed into each other. The TOF-MS signal dependence on the intensity of the laser is studied in detail. The fast deuteron intensity is independent of the laser power over a large range, which suggests that D(−1) is a superfluid with long-range efficient transport of excitation energy or particles.

Experimental studies of fast fragments of H Rydberg matter

A comprehensive pulsed-laser time-of-flight (TOF) study of H Rydberg matter (RM) fragments is presented. The nature of the fragments released with well-defined kinetic energies of 9–24 eV is investigated: the detected fragments are found to be H* in Rydberg states with principal quantum number n > 28. The only way to produce such states is from Coulomb explosions in a pre-formed easily laser-fragmented molecular entity. Non-symmetric angular distributions of the fragments are measured and Coulombic shockwave phenomena are observed, which prove that the phase of origin is not a gas but an RM phase. The fast particles are concluded to be formed in two-, three- and four-particle Coulomb explosion processes in an H RM cluster. Laser intensity variation measurements indicate that between four and six photons with a total energy of 8.8–13 eV take part in the RM fragmentation. This proves that laser-induced processes in H2 or H2+ molecules, even in the RM phase, are excluded for energetic reasons. A feasible H RM formation mechanism is deduced from the signal variation with H2 pressure, with the dissociation of H2 on the emitter surface as the rate limiting step. The principal quantum number of H Rydberg species H* reaching the detector is estimated to be n > 32 from a comparison of the calculated ionization rate of the H* species in the electric field inside the detector with measurements.

Production of ultradense deuterium: A compact future fusion fuel

Ultradense deuterium as a nuclear fuel in laser-ignited inertial confinement fusion appears to have many advantages. The density of ultradense deuterium D(−1) is as high as 140 kg cm−3 or 1029 cm−3. This means that D(−1) will be very useful as a target fuel, circumventing the complex and unstable laser compression stage. We show that the material is stable apart from the oscillation between two forms, and can exist for days in the laboratory environment. We also demonstrate that an amount of D(−1) corresponding to tens of kilojoules is produced in each experiment. This may be sufficient for break-even.

Planar clusters of Rydberg matter KN (N=7, 14, 19, 37, 61) detected by multiphoton fragmentation time-of-flight mass spectrometry

Abstract We report a direct observation of large planar clusters characteristic for Rydberg matter. This state of matter has low density with interatomic distances of the order of tens of nanometers. We observe the laser multiphoton-induced fragmentation and ionization of potassium clusters K N + with N (the magic numbers) =7, 14, 19, 37 and 61 in processes due to 5–12 photons of 2.2 eV (564 nm) in 5 ns pulses, using time-of-flight (TOF) mass spectrometry. The clusters are formed by desorption of K * Rydberg atoms from a basal graphite surface, which is intercalated by a weak molecular beam of K. The fragmentation is strongly influenced by the electric field used, below 4 V/cm. The efficient multiphoton fragmentation is probably due to the low rate of E–V transfer in the cluster.

Cluster KN formation by Rydberg collision complex stabilization during scattering of a K beam off zirconia surfaces

The molecular beam scattering of a K atom beam off a zirconia surface at 1100 K is studied with four different detection techniques: field ionization, which is sensitive only to field ionizable Rydberg species, in this case, with principal quantum number n>29; ion collection, which is sensitive only to positive ions; ion multiplier detection, which will give a response for both positive ions and Rydberg species; and finally, surface ionization detection, which will give a signal proportional to the flux of all forms of K, including excited K* species and clusters KN. Combining all these methods, the different scattering processes can be disentangled. A condensation scattering process is observed between a K beam atom and an electronically excited cluster KN* at the surface. This is seen in the angular distributions as several sharp peaks in the angular directions of the center-of-mass motion for the complexes formed. Electronically excited species K* and KN* are formed by thermal excitation due to mechani...

Optical stimulated emission transitions in Rydberg matter observed in the range 800–14 000 nm

The stimulated emission signal from a tunable cavity with Rydberg matter as the lasing medium is studied. The Rydberg matter is excited by heating through a non-radiative process. The emission bands are resolved by diffraction up to the fifth order using several different gratings in the cavity. The signal variation with wavelength is strong, especially in the wavelength range <2000 nm. The wavelength variation of the signal over the range 800–14 000 nm is compared with Rydberg matter theory giving good agreement. The transitions observed are from down to 6–21. There are no bands in the visible range, which is explained from the possible excitation levels in Rydberg matter. Reflecting some light out of the cavity gives lower gain (higher loss) and sharper bands, demonstrating that the device is indeed a working laser.