The next generation of current measurement for ionization chambers

Area of Science:

• Metrology
• Nuclear Science
• Instrumentation

Background:

• Re-entrant ionization chambers are critical for radionuclide metrology and nuclear medicine.
• High precision (0.1%) and stability over years are required for metrology systems.
• Current measurement linearity from 10⁻¹⁴ A to 10⁻⁸ A is essential.

Purpose of the Study:

• To address challenges of aging electronics and decreasing availability of sealed sources in metrology.
• To review and discuss potential solutions for maintaining and improving ionization chamber capabilities.
• To explore alternative current measurement systems for radionuclide metrology.

Main Methods:

• Review of existing and emerging technologies for current measurement.
• Discussion of ionization chamber design and measurement methodologies.
• Evaluation of Ultrastable Low-Noise Current Amplifiers (ULCAs), resistive-feedback electrometers, and single-electron pumps.

Main Results:

• Ultrastable Low-Noise Current Amplifiers (ULCAs) show significant promise for high-precision measurements.
• Resistive-feedback systems offer a viable alternative, leveraging standard resistor calibrations.
• The study provides a comprehensive overview of potential solutions for metrology challenges.

Conclusions:

• ULCAs and resistive-feedback systems are promising solutions for future radionuclide metrology.
• Addressing electronics aging and source availability is crucial for maintaining metrology standards.
• Continued research in ionization chamber design and measurement techniques is vital.