Authors: R.A. Leske(1), E.R. Christian(2), C.M.S. Cohen(1), A.C. Cummings(1), G.A. de Nolfo(2), M.I. Desai(3,4), J. Giacalone(5), M.E. Hill(6), A.W. Labrador(1), D.J. McComas(7), R.L. McNutt Jr.(6), R.A. Mewaldt(1), D.G. Mitchell(6), J.G. Mitchell(2), J.S. Rankin(7), N.A. Schwadron(7,8), T. Sharma(7), M.M. Shen(7), J.R. Szalay(7), M.E. Wiedenbeck(9), O. Romeo(10), A. Vourlidas(6), S.D. Bale(10), M. Pulupa(10), J.C. Kasper(11), D.E. Larson(10), P. Whittlesey(10) 1) California Institute of Technology, Pasadena, CA 91125, USA 2) Goddard Space Flight Center, Greenbelt, MD 20771, USA 3) Southwest Research Institute, San Antonio, TX 78228, USA 4) University of Texas at San Antonio, San Antonio, TX 78249, USA 5) University of Arizona, Tucson, AZ 85721, USA 6) Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA 7) Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA 8) University of New Hampshire, Durham, NH 03824, USA 9) Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA 10) University of California at Berkeley, Berkeley, CA 94720, USA 11) University of Michigan, Ann Arbor, MI 48109, USA

The 5 September 2022 solar energetic particle (SEP) event, which occurred when Parker Solar Probe was only 0.07 au from the Sun, was among the largest yet seen by the EPI-Hi instrument on this spacecraft, with peak heavy ion intensities at 2-3 MeV/nucleon ~9 orders of magnitude above the quiet-time galactic cosmic ray background. At such high count rates, the instrument automatically reduces its sensitivity to H, He, and electrons, but retains the ability to measure heavy-ion anisotropies, spectra, and composition up to Fe. We find that before the shock arrival the particle distributions were highly anisotropic (flowing outward from the Sun) with very soft spectra (with differential intensities proportional to approximately E^-8) and compositionally extremely depleted in Fe (with an upper limit on the Fe/O ratio more than a factor of 100 lower than the average seen in large SEP events). As the shock arrived, the particle intensities dropped by about an order of magnitude. Intensities recovered about a half hour later, perhaps inside a magnetic cloud, with much harder spectra (E^-4 or harder) and a large excess of particles flowing back towards the Sun. We present these and other details of the measured heavy ion behavior during various periods throughout this event, and compare with changes in the plasma and fields environment measured by the SWEAP and FIELDS instruments on Parker.