Fully-Depleted p-Channel SiSeRO-CCD Demonstrates Sub-Electron Noise Performance in X-ray Characterization
Researchers have characterized a fully depleted, 725-micrometer-thick p-channel SiSeRO-CCD detector, demonstrating high-resolution X-ray spectroscopy from below 6 keV up to 59.5 keV. The device achieved an energy resolution of 54 ± 0.9 eV at 5.9 keV for single-pixel events using a non-destructive multi-sample readout amplifier. This combination of sub-electron noise and efficient charge collection in a thick silicon sensor could benefit astrophysical instrumentation requiring sensitivity across a wide X-ray energy range.
A team affiliated with Fermilab has published X-ray characterization results for a fully depleted p-channel SiSeRO-CCD with a silicon thickness of 725 micrometers. Using an iron-55 radioactive source, the detector achieved an energy resolution of 54 ± 0.9 eV (14.6 ± 0.25 electrons) at 5.9 keV for single-pixel events, demonstrating that the SiSeRO amplifier's non-destructive readout preserves the intrinsic charge resolution of the underlying CCD. Characterization with an americium-241 source extended the measured spectral response to higher energies, with reconstructed features observed between 9 and 26 keV and detection of the 59.5 keV gamma emission. A muon-derived diffusion calibration further confirmed that charge transport and diffusion are consistent with photon interactions spanning the full sensor depth. Together, these results establish that the SiSeRO-CCD simultaneously achieves sub-electron noise and efficient charge collection in a thick, fully depleted silicon device. The work, reported as FERMILAB-PUB-26-0218-PPD, suggests the technology is well-suited for broad-band X-ray spectroscopy applications, including space-based astrophysical instruments requiring sensitivity to faint signals.
What's missing
The preprint has not yet undergone formal peer review. The study does not report direct comparisons with competing detector technologies (e.g., conventional CCDs or HgCdTe arrays) under identical conditions, nor does it address radiation hardness or long-term stability relevant to space deployment. Scalability to larger detector arrays and manufacturing yield are not discussed.
What different sources said
- arXiv physicsCenter
X-ray Response of the Fully-Depleted, p-Channel SiSeRO-CCD
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