The solenoidal-spectrometer technique for the study of direct reaction in inverse kinematics was developed at Argonne some 15 years ago in the form of HELIOS. The technique continues to evolve, with new capabilities being added.

A device inspired by HELIOS has been recently installed at the Facility for Rare Isotope Beams (FRIB), called SOLARIS, for use with reaccelerated (ReA) beams. SOLARIS builds on the solenoidal-spectrometer technique and other parallel developments, operating as a dual-mode spectrometer, both in a vacuum with position-sensitive silicon arrays and in Active-Target Time Projection Chamber (AT-TPC) mode. This allows for reaction studies across a broad dynamic range in terms of beam intensities (hundreds of particles per second to nano-Ampere beams), masses, and incident beam energies.

The capabilities of these two devices will be demonstrated via a series of recent highlights: for HELIOS, the role of quenching in weakly-bound systems using the (d,p) reaction, and for SOLARIS studies using the (t,p) reaction where the inverse kinematics technique allows for almost background-free measurements and a determination of branching ratios of unbound states.

*This material is based upon work supported the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract Number DE-AC02-06CH11357 (Argonne). SOLARIS is funded by the U.S. Department of Energy, Office of Science, under the FRIB Cooperative Agreement DE-SC0000661.