Fig. 1: Experimental setup.
a, Overview of the trap system components of the BASE-STEP apparatus used in this study. Parts of the full trap system9 have been omitted, and the field emission point was moved closer to the proton cloud for better visibility. A cloud of protons is created by an electron beam from the field emission point and stored inside the cylindrical electrodes of the trap. The image-current detector (which is used for non-destructively monitoring the trap content), the rotatable degrader stage and the transfer channel (which is used for ejecting into another trap system) are shown. b, A model of the transport frame containing the superconducting magnet with the trap system inside. The frame contains the UPS batteries, a control PC, frequency generators for particle manipulation and detection, voltage supplies for trap biasing, amplifiers and heaters.
