Helical orbit spectrometer

The helical orbit spectrometer (HELIOS) is a measurement device for studying nuclear reactions in inverse kinematics.

The HELIOS concept was first proposed at the Workshop on Experimental Equipment for an Advanced ISOL Facility at Lawrence Berkeley National Laboratory in 1998.

Accelerated heavy-ion beams enter the solenoid along the magnetic axis, passing through a hollow detector array.

In the configuration shown in the figure, charged reaction products ejected rearward in the laboratory frame move in helical orbits to the detector array.

This first commissioning measurement studied the well-known nuclear reaction 28Si(d,p) in inverse kinematics in order characterize the performance of the spectrometer.