[en] The Applied-B diode has produced the highest brightness proton beam of any diode at the 1 TW and 3 TW power levels on the Proto-I and Proto-II accelerators. An experiment has begun on PBFA I to study the diode's electrical coupling to the accelerator, ion conversion efficiency, and focusability of the proton component of the beam. The particular diode is a slightly larger version of a diode used successfully on Proto II. The diode radius has been increased from 14 cm to 15 cm, and the height from 5 cm to 6 cm, increasing the diode area from 440 cm² to 560 cm² to accomodate PBFA-I's lower output impedance. Current neutralized beam propagation is provided by injecting the beam into a gas cell with a 2 m mylar window a few mm from the AK gap, typically filled with 5 Torr argon. We will discuss the status of these experiments