Accurate Signal Conditioning for Pulsed-Current Synchronous Measurements

Area of Science:

• Electronics
• Measurement Science
• Medical Physics

Background:

• Accurate measurement of pulsed-current signals is crucial for advanced applications.
• Conventional measurement systems struggle with high precision for narrow pulses and low duty cycles.
• Existing instrumentation exhibits significant reading errors under specific signal conditions.

Purpose of the Study:

• To develop a compact electronic system for precise pulsed-current signal acquisition.
• To enhance signal-to-noise ratio (SNR) compared to conventional free-running measurements.
• To validate the system's performance with narrow pulses and low duty cycles.

Main Methods:

• Implementation of a synchronous demodulation measurement technique.
• Fabrication and testing of a prototype electronic system.
• Comparative analysis with high-precision electrometers under varying duty cycles (D).

Main Results:

• The prototype achieved a signal-to-noise ratio superior to conventional methods, especially for narrow pulses.
• A consistent reading error of approximately 0.1% was observed across the duty cycle range of 10−4 to 10−3.
• Conventional electrometers showed errors up to 30% at D = 10−4, improving to <1% only for D > 3 × 10−3.

Conclusions:

• The developed system demonstrates exceptional accuracy and low error rates for pulsed-current measurements.
• Field tests confirmed its effectiveness when coupled with dosimeters in medical linear accelerator environments.
• The technology is suitable for real-time monitoring in modern radiotherapy utilizing ultra-narrow photon or particle pulses.