Muon catalyzed fusion in a dense triple mixture of hydrogen isotopes was in
vestigated for the first time. The experimental method is based on the regi
stration of neutrons from dt mu fusion by a full absorption detector in 4 p
i geometry. The measurements were performed in H/D/T mixture at T = 21 K an
d phi similar or equal to 1.1 LHD using four sets of isotope concentrations
. The basic parameters of the dt mu cycle (neutron yield, cycling rate and
total sticking) in H/D/T mixtures obtained from neutron time distributions
are presented and discussed.