Technique for Recovering Pile-up Events from Microcalorimeter Data

Area of Science:

• Physics
• Astrophysics
• Instrumentation

Background:

• Microcalorimeter detectors are crucial for high-resolution X-ray spectroscopy.
• Conventional optimal filtering techniques can limit data analysis efficiency due to dead time between detected pulses.

Purpose of the Study:

• To develop and validate a novel data processing technique for microcalorimeter arrays.
• To improve the live-time of data acquisition by efficiently handling closely spaced pulses.
• To maintain or enhance spectral resolution compared to existing methods.

Main Methods:

• A new filtering approach is applied to the entire pixel data stream, optimizing for both pulse amplitude and arrival time.
• Filtered pulse templates are used to simultaneously fit multiple pulses within the data stream.
• Calibration data from the X-ray Quantum Calorimeter (XQC) sounding rocket payload was utilized for analysis.

Main Results:

• The technique significantly improves live-time compared to conventional optimal filtering.
• Closely spaced pulses, separated by as little as the detector rise-time, were successfully recovered.
• No observable spectral broadening was detected, indicating preserved spectral resolution.

Conclusions:

• The developed technique offers a superior method for processing microcalorimeter data.
• This advancement is particularly beneficial for experiments requiring high throughput and resolution, such as X-ray astronomy.
• The method demonstrates robust performance in recovering closely spaced events, enhancing the scientific return from microcalorimeter instruments.