  Context. The remote observations of solar flare ion acceleration are rather
limited. There are theoretical predictions for signatures of ion acceleration
in EUV line profiles. Previous tests involve observations of flares with no
evidence for energetic ions. Aims. We aim to examine a source flare of
impulsive (or 3He-rich) solar energetic particle events with EUV line
spectroscopy. Methods. We inspect all (90+) reported 3He-rich flares of
previous solar cycle 23 and find only four (recurrent) jets in the field of
view of SOHO CDS. The jet with the most suitable spatial and temporal coverage
is analyzed in detail. Results. Two enhanced (non-thermal) line broadenings are
observed in the cooler chromospheric / transition-region lines and they are
localized near the site where the closed magnetic loops reconnect with the open
magnetic field lines. Both enhanced broadenings are found in the sites with
redshifts in the lines, surrounded by the region with blueshifts. One enhanced
line broadening is associated with a small flare without energetic particle
signatures while another occurs just after the particle acceleration signatures
of the main flare terminated. Conclusions. The observed excess broadening
appears to be not directly related to the energetic ion production and motions.
Further investigations where the critical impulsive phase of the flare is
covered are required, ideally with high-resolution spectrometers intentionally
pointed to the 3He-rich solar energetic particle source.
