Detector Development for the abBA Experiment.

Area of Science:

• Nuclear Physics
• Particle Physics
• Spectroscopy

Background:

• Neutron beta decay provides a sensitive probe of the weak interaction.
• Precise measurements of decay correlations (a, b, B, A) are crucial for testing the Standard Model and searching for new physics.
• Existing experimental methods face limitations in detector performance and precision.

Purpose of the Study:

• To develop and test a novel field-expansion spectrometer for measuring neutron beta decay correlations.
• To evaluate the performance of silicon detectors for charged particle detection in coincidence.
• To establish stringent requirements for detector characteristics like energy and timing resolution, dead layer thickness, and efficiency.

Main Methods:

• Design and implementation of a new field-expansion spectrometer.
• Utilizing large-area segmented silicon detectors for simultaneous proton and electron detection.
• Testing commercially available surface-barrier silicon detectors for energy and timing resolution.
• Measuring the dead-layer thickness of ion-implanted silicon detectors using a 3.2 MeV alpha source.

Main Results:

• The developed spectrometer is designed to meet the stringent requirements for precision neutron beta decay measurements.
• Initial testing of silicon detectors shows promising energy resolution (< 5 keV) and timing performance (~1 ns).
• Dead-layer thickness measurements are critical for observing low-energy protons (30 keV).

Conclusions:

• The new spectrometer design and tested silicon detectors offer a promising approach for advancing neutron beta decay studies.
• Achieving high precision in these measurements requires careful selection and characterization of detector components.
• Further development and optimization are expected to yield significant results in fundamental physics.