Nuclear effects mean free path

If nuclear matter is considered as a degenerate Fermi gas, it is clear that collisions with small momentum transfers will be discouraged, since these tend to lead from an occupied state to another already occupied. An estimate of this effect indicates that as a result the mean free path of a high energy particle ( lOOMev) traversing nuclear matter will be increased over what would be expected for collisions between free particles by a factor of f. . . "... 

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