FEASIBILITY OF HEAVY-BOSON SUPERCONDUCTIVITY

Deuterons are bosons and as such, under proper conditions, will Bose c ondense. A configuration which permits this phenomenon is described in which deuterons are weakly bound at interstitial sites of the metal p alladium. It is argued that at a moderate value of the deuterium-to-pa lladium concentration ratio, a magnetically driven current in a single -crystal loop of this material will become ''class B'' superconducting at the critical temperature, T(c), where ''class B'' denotes heavy-bo son charge flow. Two distinct regimes are examined in which the deuter on kinetic energy, E, is large or small compared to the activation ene rgy, E(a). In the domain E< E(a), stemming from the London criterion f or Bose-condensation and the tunneling matrix element, an expression f or T(c) is obtained which, for deuteron propagation in palladium, is n oted to be infinitesimally small, rendering the proposed phenomenon un feasible. In the domain E > E., first-order estimates of the nearly-fr ee-particle model, together with the London criterion, give the critic al value T(c) almost-equal-to 9.1 K. It is shown that the condition E > E(a) may be established for sufficiently short rise time of an impos ed magnetic field. A calculation is included which indicates that at t hese low temperatures, phonon effects in the present model are minimal . Metallurgical limitations on obtaining a single-crystal loop of pall adium, with the fcc structure continuously maintained, imply the condi tion rho greater-than-or-equal-to 1.75 X 10(3)b, where rho is the radi us of curvature of the palladium current loop and b is its diameter.