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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Kinematic constraints on the production of magnetic monopoles

A strict lower limit is derived for the laboratory kinetic energy of a magnetic monopole produced from a target at rest. The production of a monopole-antimonopole pair via the collision of a projectile with a target at rest in the laboratory is analyzed in terms of the velocity of the zero-momentum frame, the velocity of the monopole in that frame, and the velocity of the monopole in the laboratory. The limit obtained is applied to the data of Price et al. (1975), and almost all means of producing the monopole in the atmosphere immediately above the balloon-borne detectors are ruled out. Some mechanisms for slowing a monopole following its production are briefly considered.

Wilson, L. W.↗
DOE OSTI2022

Charged particle motion in spherically symmetric distributions of magnetic monopoles

The classical equations of motion of a charged particle in a spherically symmetric distribution of magnetic monopoles can be transformed into a system of linear equations, thereby providing a type of integrability. In the case of a single monopole, the solution was given long ago by Poincaré. In the case of a uniform distribution of monopoles, the solution can be expressed in terms of parabolic cylinder functions (essentially the eigenfunctions of an inverted harmonic oscillator). Further, this solution is relevant to recent studies of nonassociative star products, symplectic lifts of twisted Poisson structures, and fluids and plasmas of electric and magnetic charges.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
NASA NTRS1985

Magnetic monopole search by 130 m(2)sr He gas proportional counter

A search experiment for cosmic ray magnetic monopoles was performed by means of atomic induction mechanism by using He mixture gas proportional counters of the calorimeter (130 square meters sr) at the center of the Akeno air shower array. In 3,482 hours operation no monopole candidate was observed. The upper limit of the monopole flux is 1.44 x 10 to the minus 13th power cm-z, sec -1, sr-1 (90% C.L.) for the velocity faster than 7 x 0.0001 c.

Hara, T.↗
DOE OSTI2021

The color of magnetic monopole noise

We relate the anomaly in the noise color of spin ice to the emergent nature of its magnetic monopoles and their random walk. Monopoles are quasi-particles, and the spin vacuum in which they wander is not structureless. Rather, the underlying spin ensemble filters the thermal white noise, leading to non-trivial coevolution. Thus, monopoles can be considered as "dressed" random walkers, activated by a non-trivial stochastic noise that subsumes mutual interactions and the coevolution of their spin vacuum. From this, we suggest that recent experimental results are interpretable in terms of monopole subdiffusion. Furthermore, we then conjecture relations between the color of the noise and other observables, such as relaxation time, monopole density, the dynamic exponent, and the order of the annihilation reaction, which suggests to us the introduction of spin-ice-specific critical exponents in a neighborhood of the ice manifold criticality.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
NASA NTRS1985

Upper limit on magnetic monopole flux from Baksan experiment

No indication of slowly moving penetrating particles in cosmic radiation underground was found during two years observation. Particle velocity and pulse shape are main criteria for search. Probability of the imitation of slow particles (Beta 0.1) by atmospheric muons is negligible. Our upper limit on superheavy magnetic monopole flux is now 1.86 x 10 to the minus 15th power cm(-2) sr(-1) s(-1) (90% c.l.) for velocity range 2 x 0.0001 beta 0.1.

Alexeyev, E. N.↗
NASA NTRS1985

Search for supermassive magnetic monopoles using mica crystals

The survival of the Galactic magnetic field almost certainly sets an astrophysical upper bound of approx. 10 to the minus 15th power cm(-2) sr(-1) s(-1) on the flux of monopoles. To improve significantly upon this Parker limit with direct, real time searches would require a detector area of approx. 10,000 square meters and a collection time of years. Several such searches are being contemplated. A novel alternative scheme using large mica crystals capable of recording and storing tracks of slow monopoles over a time scale of approx. 10 to the 9th power years was proposed.

Price, P. B.↗
NASA NTRS1972

Why does the sun sometimes look like a magnetic monopole?

For several months in early 1965 the sun appeared to have large scale magnetic field directed outwards at nearly all latitudes and longitudes. Several independent observations that lead to this puzzling situation are discussed.

Wilcox, J. M.↗
NASA NTRS1972

Why does the sun sometimes look like a magnetic monopole.

For three or four consecutive months in 1965 observations of the sun's magnetic field showed that it was predominantly directed out of the sun at all solar latitudes. This interval in the first part of 1965 is near the minimum of the sunspot cycle. Solar activity has been strongly associated with large-scale solar regions with field directed predominantly into the sun, while the observations noted seem to show that just near solar maximum there is almost no field observed to be directed into the sun. An attempt is made to describe and develop these interesting circumstances.

Wilcox, J. M.↗
NASA NTRS1975

Orion-arm magnetic monopoles and gamma rays

It is shown that galactic-disk monopoles could yield air showers which are stochastically aligned with the local Orion-arm magnetic field and which are above the energies of similarly aligned galactic heavy nuclei. In the absence of a cosmic-ray anisotropy, this method sets limits on the flux of galactic monopoles and their production cross sections. Limits based on the cosmic-ray anisotropy at 10 to the 19th power eV are presented. The possibility of stochastic alignment of inverse Compton photons from monopoles and 2.7 K black-body photons is considered. The resulting monopole-flux limits, based on the same data as those calculated by Osborne (1970), differ significantly from Osborne's limits, where the mechanisms of spiral-arm alignment and galactic containment are ignored.

Tompkins, D. R., Jr.↗
NASA NTRS1988

Superheavy magnetic monopoles and main-sequence stars

The interactions of superheavy monopoles with stars of mass 0.6-25 solar masses are studied. It is shown that captured monopoles cluster near the stellar center, and that their contribution to the total stellar luminosity and their effects on the structure of stars will be unobservable as long as the flux is significantly below the Parker (1970, 1971) bound. It is suggested that all but the strongly magnetic stars will retain a substantial fraction of the monopoles they capture.

Frieman, Joshua A.↗
NASA NTRS1978

Further measurements and reassessment of the magnetic-monopole candidate

The data on the 1975 Lexan event are reexamined in a framework that does not depend on the details of a particular track model. Instead, visual measurements of two quantities, photographic evidence, and silver-grain densities measured with an automated microscopic-image dissector are cited. It is shown that throughout the detector stack the particle had a roughly constant value of absolute Z/beta of about 109-114 based on energy deposition at radial distance less than about 0.01 micron. Its energy deposition at radial distance greater than about 20 microns was incompatible with that expected from any known cosmic ray nucleus with Z/beta in this range. A monopole is ruled out, and the three candidates compatible with the data are: (1) a slow, supermassive particle with beta about 0.4, charge about 45e, and mass above 1000-10,000 amu; (2) a fast antinucleus with Z/beta about -109 to -114 and absolute Z between 76 and 96; and (3) a very fast nucleus with Z about 110-114 and beta above about 0.99.

Price, P. B.↗