Since its beginning ATLAS has had both Faraday Cups to measure beam current, and Beam Profile Monitors (BPM) to trace the beam profile. However only the Faraday Cups are used to perform objective beam measurements during tuning and delivery, because cups block the beam during measurements. ATLAS has approximately 41 BPMs which utilize a helically wound wire that continuously sweeps the Y and X profile but does not block beam. The output of these BPMs is sent through a series of multiplexers to an oscilloscope in the control room where operators can see the Y-X sweeps in real-time, as well as capture the waveform on-demand. To make the BPMs more useful for everyday beamline operations, a tighter coupling of the BPMs to the control system is required. The first step is to continuously capture the BPM signal by the control system. Once continuous capture is implemented, software tools to store, analyze, and display key metrics from the BPMs are required to make use of the data. The system would primarily be used as a minimally-invasive approximation of continuous real-time beam current monitor, capable of measuring light ions.

The Argonne Tandem Linac Accelerator System (ATLAS) has been a National User Facility since 1985. Since the commissioning of the Californium Rare Isotope Breeder Unit (CARIBU) in 2012, it has used 2 bespoke water-cooled linear power supplies to allow for milliamp control of the isobar separator magnets, which allows for milligauss control of the magnets. During the upgrade to nuCARIBU, the aging linear power supplies were replaced with off-the-shelf (OTS) switched mode power supplies (SMPS). The benefit of the SMPS is higher efficiency and since they are air-cooled, no load on the water cooling system, while the detriment is the decrease in resolution of the current control. To overcome this limitation, a device was constructed that allows control of a sub-milliamp constant current sink, which is placed in parallel to the magnet. This arrangement allows the control system to “leak” a precise amount of current away from the magnet, effectively giving sub-milliamp control of the current going into the magnet.