Accession Number : ADA304210

Title :   Nonmonoenergetic Beam With Helical Cerenkov Radiation: Possible Technique to Determine Magnetic Field in a Hostile Electromagnetic Environment.

Descriptive Note : Final rept. Oct 94-Jun 95,

Corporate Author : ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD

Personal Author(s) : Soln, Josip Z.

PDF Url : ADA304210

Report Date : JAN 1996

Pagination or Media Count : 24

Abstract : Modifications caused by the nonmonoenergetic beams to the recently described helical Carenkov radiation (resulting from electron helical motion in a medium under the influence of magnetic field) are studied in a visible portion of the spectrum. The analysis is greatly simplified by utilizing a new analytical approximate expression for the number of emitted photons per unit path length for the usual 'monoenergetic' helical Carcknov radiator. The effect of the nonmonoenergetic beam is that simultaneously with the helical Carenkov radiation also the radiation into harmonics (above and below the helical Carenkov effect threshold) may occur at the same radiation angle and at the same visible frequency. Hence, harmonic radiators may enhance the usual helical Carenkov radiation. For the medium of silica aerogel with the index of refraction of 1.075 and the beam energy in the 2-3-MeV range interacting with the magnetic field of about 10 T, one estimates that in the visible portion of the spectrum an electron from a noumonoenergetic beam will generate between 1 and 2 photons at the end of the 10cm interaction length. This shows the possibility of detecting a magnetic field coming from an electromagnetic treat wave form, which in turn, represents a hostile electromagnetic environmental The importance of detecting this magnetic field comes from the fact that in an environmental medium it can disrupt optical signals. Here we show the way for measuring and quantifying such disruptions. (AN)

Descriptors :   *MAGNETIC FIELDS, *DIELECTRICS, *CERENKOV RADIATION, *ELECTROMAGNETIC ENVIRONMENTS, HARMONICS, REFRACTIVE INDEX, POWER SPECTRA, ELECTROMAGNETIC WAVE PROPAGATION, ELECTRON BEAMS, APPROXIMATION(MATHEMATICS), VISIBLE SPECTRA, PHOTONS, ELECTRON IRRADIATION, ENERGETIC PROPERTIES, BESSEL FUNCTIONS, SILICA GELS.

Subject Categories : Nuclear Physics & Elementary Particle Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE