Experimental evidence for an ascending microflow of geogas in the ground

A microflow of free ascending gas has been observed in 26 out of 30 tested boreholes at three different sites. The flow rates vary between 60 × 10⁻⁴ and 4 cm³/min m² horizontally projected borehole area. Sampling has been made in ground boreholes as well as in holes drilled downwards from the lowest levels in two mines. The composition of the gas varies considerably. The main components of the gas are nitrogen, argon, oxygen and methane. Traces of heavier hydrocarbons are observed. At the site of the ground holes, only traces of methane are observed. In all sampled holes the existence of free oxygen is observed. The nitrogen/argon quotient is close to the atmospheric quotient in all sampled holes, indicating a partly atmospheric origin of the gas. The existence of methane and traces of heavier hydrocarbons indicates the existence of a second source.     

Composition of low energy cosmic radiation from silicon to nickel

The charge composition of the cosmic radiation for the elements withZ14 has been studied in a stack of nuclear emulsions exposed at Fort Churchill in July 1967. Particles stopping in the stack have been measured with a nuclear track photometer to determine the charge. Relative abundances are given for the elements silicon to nickel and comparison is made with other investigations.     

A possible mechanism for the injection of particles into a cosmic ray acceleration region

The composition of the nucleonic component of the primary cosmic radiation has been compared with the natural abundance of the elements. A normalized quotient between the abundance of an element in the radiation and in nature was found to be approximately equal toZ , whereZ is the atomic number and is a constant approximately equal to one. The observed excess of the heavy elements can be expected in the radiation if the selection of the cosmic ray particles is performed by ionization through fast electron or proton impacts on neutral matter having normal composition. Such a selection mechanism may act in regions in space where fast moving thin plasma clouds collide with clouds of neutral matter. A source model in which the plasma clouds originate in Type II supernova explosions is discussed.     

Further evidence for a cosmic ray selection mechanism

A comparison has been made between the overabundance of heavy elements in the primordial cosmic radiation and the cross-section for ionization by charged particle impacts. It is found that there is evidence that this type of ionization is important for the selection of cosmic ray particles.     

Boron substitution in diopside evaluated through 11B nuclear reaction analysis

 Nuclear reaction analyses on boron in flux-grown Me³⁺- and Na⁺-doped diopside crystals utilising the ¹¹B(p,2α)⁴He reaction in conjunction with EMP analyses for major elements and optical absorption spectroscopy for determination of Me-valence state distributions show that appreciable amounts of B may enter the diopside lattice in crystals produced in Na₂B₄O₇ fluxes. The results indicate that the substitution ^[6]Me^3+[4]B^3+[6]Mg²⁺ ₋₁ ^[4]Si⁴⁺ ₋₁ operates in the present diopside samples in addition to the coupled substitution ^[6]Me^3+[8]Na^+[6]Mg²⁺ ₋₁ ^[8]Ca²⁺ ₋₁. The specific NRA technique applied allows for quantitative, high resolution (ca. 5 μm) B analyses at ppm level as well as high-resolution and high-contrast imaging of B-concentration patterns in minerals. The estimated detection limit and relative error of the B analyses are 10 ppm and 5–10%, respectively. Received: 20 September 1999 / Accepted: 6 June 2000     

Isotopic composition of primary cosmic-ray nitrogen and oxygen with consequences for source models

An experimental investigation of the isotopic composition of cosmic-ray nitrogen and oxygen is reported. The detector is a stack of nuclear emulsions exposed at about 3 g cm^–2 atmospheric depth. The mass determinations are based on photometric track width measurements on stopping nuclei. The standard deviation of the mass measurements is 0.46 AMU for nitrogen and 0.50 AMU for oxygen. The energy of the measured nuclei falls in the interval 220–450 MeV nucleon^–1 at the top of the atmosphere.The measured isotopic quotients have been extrapolated to near interstellar space with standard methods. The extrapolated quotients are¹⁵N/N=0.34±0.10,¹⁷O/O=0.02±0.03,¹⁸O/O=0.07±0.03. The nitrogen quotient extrapolated to the cosmic-ray source shows that the nitrogenoxygen abundance ratio is approximately the same in the source as in the solar system. The result has been compared with different hypotheses about the source composition and is found to be in best agreement with a hypothesis which states that source matter has approximately the composition of the solar system and that a selection mechanism, which depends on the atomic properties of the elements, is working in the source.     

The relative abundance of the carbon isotopes12C and13C in primary cosmic radiation

Mass measurements have been performed on stopping cosmic ray carbon nuclei in a nuclear emulsion stack, which was exposed to the primary radiation in a high altitude balloon flight. The mass determinations are based on measurements of mean track width and residual range in the range intervals 0<R<0.75 mm and 1<R<12 mm. The mean track width measurements have been performed with nuclear track photometers of special construction. The mass measurements in the interval 0<R<0.75 mm have given a nearly symmetrical mass distribution. The width of the distribution is equal to that expected for a distribution which contains only one isotope. The result indicates that one of the stable isotopes is appreciably more abundant than the other. The measurements in the range interval 1<R<12 mm gave the isotopic ratio¹³C/¹²C+¹³C)=0.08. The ratio has been extrapolated to the cosmic ray source. It is found to be smaller in the source than at the point of measurement. Different assumptions about the origin of the cosmic radiation are discussed with regard to the results obtained in this investigation.     

The composition of low energy primaries withZ≥9 in cosmic radiation

Photometric mean track width measurements have been made on 81 primary particles (Z9) stopping in a nuclear emulsion stack exposed at 2.7 g/cm² of residual atmosphere at Fort Churchill, Canada. The standard deviation of the charge determinations amounts to 0.14 units of charge for oxygen and increases to 0.40 units for iron nuclei when 10 mm track is measured. The relative abundances of the nuclei in the charge interval 8Z14 are given for the energy interval 250–400 MeV/nucleon, and comparisons are performed with the results of other measurements. The VH-particles are dominated by iron. The distribution of the VH-particles seems to be consistent with the assumption that the VH-nuclei have in the mean passed through only 1.6±0.5 g/cm² interstellar matter.     

Microflow of geogas — A possible formation mechanism for deep-sea nodules

A formation model for deep-sea manganese nodules based on ascending bubble trains of geogas is proposed. The bubble train forces material in the sediments and particles adsorbed by the bubbles to the sediment—water interface where precipitation reactions occur. In the presence of a nucleating agent a nodule is formed. Such a model might explain a number of observations concerning nodular structure, genesis and distribution.     

The composition of the cosmic radiation and the atomic properties of the elements

The composition of the primordial cosmic radiation has been compared with the solar system composition and that of interstellar matter. It is found that the overabundance of an element in the radiation is approximately proportional to the cross-section for the ionization of neutral atoms of that element through fast charged particle impacts. The results strongly support the assumption that the selection of cosmic ray particles is governed by the atomic properties of the elements.