Monopoles In Cosmic Rays Research Articles

Can track-etch detector CR-39 record low-velocity GUT magnetic monopoles?

A set of new data on the response of the CR-39 detector to low-energy heavy ions, collected with a recently developed technique based on atomic force microscopy, was used to evaluate the effectiveness of nuclear stopping in producing etchable tracks relative to electronic stopping. The results for two types of CR-39 are found to be significantly different from those obtained previously with other methods. I discuss the implications of the use of CR-39 for detecting particles with low ionization rates such as supermassive magnetic monopoles in cosmic rays as cosmological relics.

Search for cosmic-ray magnetic monopoles using a three-loop superconductive detector.

Superconducting detectors are ideal for the search for magnetic monopoles since their sensitivity is calculated from classical properties and is independent of the particle's mass, velocity, electric charge, or magnetic dipole moment. We describe the design and the completed operation of a superconducting three-loop inductive detector to search for magnetic monopoles in cosmic rays. The three-loop detector, with a total sensing area of 476 ${\mathrm{cm}}^{2}$ averaged over $4\ensuremath{\pi}$ sr, was in operation for 1008 days. During that time, the detector logged 24 190 h of active operation. These data set an upper limit of 4.4\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}12}$ ${\mathrm{cm}}^{\ensuremath{-}2}$ ${\mathrm{s}}^{\ensuremath{-}1}$ ${\mathrm{sr}}^{\ensuremath{-}1}$ at 90% C.L. ($\frac{2.3}{\ensuremath{\int}dAd\ensuremath{\Omega}\mathrm{dt}}$) on any uniform flux of magnetically charged particles of any mass passing through the Earth's surface at any velocity.

Search for superheavy grand unified magnetic monopoles in cosmic rays.

A search for superheavy grand unified magnetic monopoles has been performed utilizing a 7.3 x 7.3-m/sup 2/ array of scintillation counters, sited underground at a depth of 1148 hg/cm/sup 2/. This apparatus measures both the time of flight and specific ionization of particles passing through it and has a trigger which is sensitive to prompt as well as very slowly developing pulses from the detector. No monopole events were observed during 6700 h of live-time operation of this detector, yielding an upper limit on the flux of monopoles of 4.6 x 10/sup -14/ cm/sup -2/sr/sup -1/sec/sup -1/ (90% confidence level) in the velocity range 8.5 x 10/sup -4/c to 0.012c.

Cosmic-ray monopole search at IBM-BNL using superconducting induction detectors

Supermassive magnetic monopoles are an inevitable consequence of all Grand Unified Theories (GUT's). They would have originated in the very hot early universe some 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-35</sup> sec. after the Big Bang when the unified force split apart into the strong and electroweak forces. Over thirty laboratories throughout the world have constructed or are presently constructing detectors to search for such primordial monopoles in cosmic rays. This paper, partly tutorial, reviews the past monopole detector work at IBM and describes the present effort to set-up at the Brookhaven National Laboratory a large-area superconducting induction detector. Two detectors are being built based upon the high-order gradiometer, fully coincident, closed-box design previously developed at IBM. The first, utilizing an existing magnet-testing dewar at BNL, is a rectangular parallelopiped detector of 1.0 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> effective area (averaged over 4π sr for isotropie flux) being built to test the feasibility of large area schemes in preparation for construction of a much larger 4.0 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> octagonal prism detector. The latter could serve as the prototype for an array of detectors to reach the Parker bound on monopole flux set by the existence of the 3 μG galactic magnetic field in several years of operation.

The physical and chemical aspects of the search for superheavy elements

Abstract