Abundances of trans-iron elements in solar energetic particle events

We report the first comprehensive observation of the abundances of heavy elements of atomic number Z in the range 34 less than or equal to Z less than or equal to 82 in solar energetic particle (SEP) events as observed on the Wind spacecraft. In large gradual SEP events, abundances of the element groups 34 less than or equal to Z less than or equal to 40, 50 less than or equal to Z less than or equal to 56, and 70 less than or equal to Z less than or equal to 82, relative to Fe, are similar to corresponding coronal abundances within a factor of similar to 2 and vary little with time during the events. However, in sharp contrast, abundances of these ions from impulsive flares increase dramatically with Z so that abundances of Fe, 34 less than or equal to Z less than or equal to 40, and 50 less than or equal to Z less than or equal to 56, relative to O, are seen at similar to 10, similar to 100, and similar to 1000 times their coronal values, respectively.