By studying the temperature (2 < T < 15K) and magnetic field (H < 12T) depe
ndences of the Hall effect in U1 - xThxBe13 with 0 less than or equal to x
less than or equal to 0.15 we have observed the transition from a magnetic
to a nonmagnetic Kondo ground state. The two-channel Kondo scaling analysis
of the nonmagnetic phase (x greater than or equal to 0.1) indicates that t
he quadrupolar Kondo temperature increases with Th content. (C) 1999 Publis
hed by Elsevier Science B.V. All rights reserved.