The helicon system’s antenna can launch waves in either direction around the torus; in one direction, the driven current adds to the pre-existing current (referred to as “co-current drive”), while in the opposite direction, the driven current is in the opposite direction as the pre-existing current (“counter-current drive”). The basic approach of this experiment involves setting up the helicon system for co-current drive and measuring the resulting currents with the Motional Stark Effect (MSE) diagnostic system. This is the goal of the first half-day of the experiment. Between the two half-days of the experiment, the helicon antenna is reconfigured for counter-current drive, and in the second half-day, the plasma is reproduced as nearly as possible, except with counter-current drive from the helicon. By subtracting the results of the counter-current cases from the co-current cases, the size of the signal should be roughly doubled, enabling an increase in the signal-to-noise ratio of what is predicted to be a small signal on the MSE measurements. In order to help calibrate the results, we also plan to do shots without helicon power with Electron Cyclotron Current Drive (ECCD) instead, at a similar power level as the helicon cases, which amounts to a single mm-wave source (gyrotron) at about a power level of 500 kW. The ECCD launcher can be reconfigured from co-current drive to counter-current drive between shots, so the comparison cases with ECCD can be done in the same half-day, the second one in this proposal. The expectation for central current drive (near the center of the plasma where the temperature is highest) is that ECCD and helicon current drive efficiency will be comparable. However, the fraction of the launched EC power that reaches the location in the plasma where the power is absorbed and the current is driven is known from previous work to be close to one. The corresponding fraction for the helicon case is not known, so that the measured current drive efficiency can give an indication of that unknown loss fraction.