Nonneutral plasma diagnostic commissioning for the ALPHA Antihydrogen experiment

The ALPHA experiment at CERN creates antihydrogen by mixing antiproton and positron plasmas. Diagnostic measurements of the precursor plasmas are performed using a diagnostic suite, colloquially known as the "stick." This stick has a variety of sensors and is able to move to various heights to align the desired diagnostic with the beamline. A cylindrical electrode, a faraday cup, an electron gun, and a microchannel-plate detector (MCP) are regularly used to control and diagnose plasmas in ALPHA. We have designed, built, and tested a new, upgraded stick which includes measurement capabilities in both beamline directions.