On the class of B1 numbers: Definition, numerical modeling, domain of existence and application

Using the relation B
1
= B
1−
− B
1+
, the class of real positive numbers B
1
is defined through the ones B
1−
and B
1+
. The elements of the latter are determined by the positive purely imaginary zeros of a complex Kummer function of specially chosen parameters and variable. A method is worked out for finding the values of B
1−
and B
1+
(of B
1
). The results of calculations are presented in a tabular and graphical form. The boundaries of the existence domain of each of the three kinds of numbers are traced. A simple formula, involving the quantities B
1
is advanced for computation of the differential phase shift provided by the azimuthally magnetized circular ferrite waveguide, propagating normal TE
01
mode.