Equating the force on a charged particle with the centrifugal force in the circle in a magnetic field, gives

$Bqv=mv^2/R$

one has the momentum.

The "texture" in the text you provide, is the ionisation of the medium through which the track passes, which is different for different masses, and can be used in determining the order of magnitude of the mass in the simple experiment you quote.

Equating the force on a charged particle with the centrifugal force in the circle in a magnetic field, gives

$Bqv=mv^2/R$

one has the momentum.

The "texture" in the text you provide, is the ionisation of the medium through which the track passes, which is different for different masses, and can be used in determining the order of magnitude of the mass in the simple experiment you quote.

Here is a book reference:

The ionization loss dE/dx is a function only of the velocity v of the particle (for a given charge), so that a simultaneous measurement of dE/dx and of the momentum p enables determining the mass m of the particle.