Developing the NewAthena X-IFU Cryogenic AntiCoincidence Detector (CryoAC): From Microfabrication Process...

Area of Science:

• Astrophysics and Space Science
• Detector Technology
• Cryogenics

Background:

• The X-ray Integral Field Unit (X-IFU) instrument for the ESA NewAthena mission requires advanced particle background reduction.
• The Cryogenic Anticoincidence (CryoAC) detector is a critical subsystem for this purpose.
• Achieving Technology Readiness Level 5 (TRL5) necessitates unified validation of fabrication and low-temperature performance.

Purpose of the Study:

• To present the development cycle of the Demonstration Model 1.2 (DM 1.2) CryoAC detector.
• To demonstrate the TRL5 achievement by validating critical technologies operating simultaneously.
• To establish and verify microfabrication processes and mK operational performance.

Main Methods:

• Established single-process verification for Iridium pulsed laser deposition, Reactive Ion Etching (RIE), and Bosch process silicon trenching.
• Fabricated three identical single-pixel prototypes for mK characterization.
• Conducted functional testing at 50 mK using a VTT FAB4 SQUID readout.

Main Results:

• Achieved a 2/3 production yield against strict design targets (T_C ~100 mK).
• Demonstrated a low-energy threshold of ~0.6 keV.
• Measured pixel power dissipation of 5.15 nW and energy resolution ΔE_FWHM = 735 eV at 6 keV.

Conclusions:

• Successfully validated the CryoAC detector's manufacturing and operational baseline for space mission requirements.
• The DM 1.2 model successfully completed the TRL5 demonstration path.
• The CryoAC technology is ready for integration into the X-IFU instrument, paving the way for future X-ray astronomy missions.