What Causes Loss of Particles in a Magnetic Mirror?

[artis]

If I am not mistaken (hopefully) then the highest loss through the mirror ends in a magnetic mirror happens with particles that have a higher parallel component to the field lines than a higher perpendicular (gyro frequency).
In a magnetic mirror if we map these properties onto the real physical picture , which particles had higher parallel speeds, those that gyrated around the straight axial center field lines or those that went around the more curved lines that were further away from the axial center?

 

[Astronuc]

If I am not mistaken (hopefully) then the highest loss through the mirror ends in a magnetic mirror happens with particles that have a higher parallel component to the field lines than a higher perpendicular (gyro frequency).

Yes, and also those particles that have most of their velocity parallel with the field lines.

There exists a small force parallel to the axis, repelling the particle away from the tip of the cone. That added force gradually slows down the particle's advance down the axis and finally reverses it, causing it to "mirror" and bounce back.

https://pwg.gsfc.nasa.gov/Education/wtrap2.html

The magnetic force opposing the particles becomes greater as the magnetic field strength (line density) increases.

Plasma confinement by magnetic mirror configuration and improvement of the confinement with the tandem mirror configuration https://www.prc.tsukuba.ac.jp/en/?page_id=806