Calibration methods of charge sensitive amplifiers at the Colorado dust accelerator

Area of Science:

• Electronics
• Instrumentation
• Particle Physics

Background:

• Charge sensitive amplifiers (CSAs) are crucial for detecting charge pulses from semiconductor detectors and electron multipliers.
• Traditional CSA calibration faces limitations due to the difficulty in accurately calibrating small injection capacitors (pF range) and mitigating stray capacitance.
• Accurate calibration is essential for the precise performance of sensitive electronic circuits.

Purpose of the Study:

• To introduce and evaluate an alternative method for calibrating charge sensitive amplifiers (CSAs) using conductive detectors.
• To compare the novel "external conductor" calibration method with the conventional injection capacitor technique.
• To validate the external conductor method against an independent calibration approach using charged particles.

Main Methods:

• Developed and implemented the "external conductor" method, utilizing the detector itself to form the injection circuit for CSA calibration.
• Performed comparative calibration of an example detector using both the external conductor method and the traditional injection capacitor method.
• Cross-validated the results obtained from the external conductor method with a calibration performed using reference charged particles in a dust accelerator.

Main Results:

• The external conductor method yielded calibration factors up to 70% higher than those obtained using the traditional injection capacitor method.
• The new calibration method demonstrated a low uncertainty of 2%.
• Results from the external conductor method were independently corroborated by the charged particle calibration approach within the stated uncertainty.

Conclusions:

• The external conductor method provides a more accurate and reliable calibration for charge sensitive amplifiers compared to traditional techniques.
• This novel method overcomes the limitations associated with small injection capacitors and stray capacitance in calibration circuits.
• The external conductor method offers a validated and precise approach for calibrating detector electronics, crucial for scientific instrumentation.