Xiao, M. Brandenburg, S. Delaviere, T. Dupuy, L. Goethem, M.J. Stulle, F. JACoW Publishing Geneva, Switzerland 2673-5350 978-3-95450-241-7 10.18429/JACoW-IBIC2022-MOP33 English 121-124 experiment proton electron electronics controls Contribution to a conference proceedings 2022 2022-12 https://doi.org/10.18429/JACoW-IBIC2022-MOP33 https://jacow.org/ibic2022/papers/mop33.pdf In conventional proton therapy (PT) typical beam currents are of the order of 1 nA. At these currents dose monitoring is reliably achieved with an ionization chamber. However, at the very high dose rates used in FLASH irradiations (employing beam currents >100 nA) ionization chambers will exhibit large intensity dependent recombination effects and cannot be used. A possible solution is a current transformer. Here we report on the performance of the LC-CWCT (Bergoz Instrumentation, France) which has been developed to push noise floor of such non-destructive current measurement systems into the nano-ampere range. We present first beam current measurements at the PARTREC cyclotron (Netherlands). Beam currents measured by the LC-CWCT and a Faraday Cup were shown to linearly correlate up to the maximum intensity of 400 nA used in the measurements. For pulsed beams, charge measured by the LC-CWCT linearly correlated with pulse length over the measurement range from 50 to 1000 µs. Measurement noise as low as 2.8 nA was achieved. The results confirm that the LC-CWCT has the potential to be applied in FLASH PT for accurate determination of beam current and macro pulse charge.