Speaker
Description
Accurate bunch-charge measurement is essential for FLASH and ultra-high-dose-rate (UHDR) electron accelerators, where therapeutic doses exceeding 40Gy/s are delivered in nanosecond-to-microsecond macropulses. We present the calibration and characterization of a non-intercepting charge measurement chain, based on a Bergoz integrating current transformer (ICT) coupled to a Libera ADC-500 digitizer, developed for the SAFEST compact C-band FLASH linac at Sapienza University of Rome. We show that conventional independent pulse-boundary detection introduces spurious pulse-width-dependent charge errors of up to 40% in the short-pulse regime, arising from ICT-induced pulse broadening rather than true chargeloss. A unified, output-driven integration window, combined with a near-zero-crossing boundary-detection method, removes this artifact entirely, achieving charge-reconstruction repeatability better than 2% and a combined measurement uncertainty of ≤2.2%, over the range 2ns–1000ns and 5pC–75nC, without any pulse-width-dependent correction factor. A segmented single-shot history buffer is further validated for dead-time-free pulse-by-pulse logging at repetition rates up to 200Hz, relevant for clinical FLASH dosimetry.
Funding Agency
The work was supported by funding from the European Union Next Generation EU through the Italian Ministry of University and Research under PNRR- M4C2-I1.3 Project PE-00000019 “HEAL ITALIA” to Sapienza
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| Supervisor's name | Enrica Chiadroni |
| Supervisor's email | enrica.chiadroni@uniroma1.it |
| Paper submission software | LATeX |