Pitch angle (particle motion) A pitch angle of 90 degrees is a particle that is locally mirroring (see: Magnetosphere particle motion). The equatorial pitch angle of a particle is the pitch angle of the particle at the Earth's geomagnetic equator. This angle defines the loss cone of a particle. The loss cone is the set of angles where the particle will strike the atmosphere and no longer be trapped in the magnetosphere while particles with pitch angles outside the loss cone will continue to be trapped. The loss cone is defined as the probability of particle loss from the magnetic bottle which is: Where
Type 97 90 mm Infantry Mortar Type 97 90 mm Infantry Mortar The Type 97 90 mm Infantry Mortar was a simplified version of the Japanese Type 94 90 mm Infantry Mortar. The Type 97 designation was given to this gun as it was accepted in the year 2597 of the Japanese calendar (1937). The Type 90-mm mortar is a Stokes-Brandt type mortar similar in appearance to the US 81-mm mortar, M1 and the Japanese Type 97 81 mm piece. It is believed that the 90 mm weapon has been introduced later than its model number would imply, as a captured specimen was marked "Model 97