Publications

Sep, 2026

Conference Paper

From Commissioning to Precision Data-Taking: Resolving Operational Challenges in the Nab Detector Systems

Our understanding of the weak mixing of quarks, described by the Cabibbo-Kobayashi-Maskawa (CKM) matrix, currently presents an anomaly. Thanks to major strides in both theory and experiment, improved precision in determinations of the first row of matrix elements has revealed disagreement with the expectation of unitarity. The Nab experiment at the Spallation Neutron Sourc…

Aug, 2026

ORNL Report

A Real-time Solution for Fast-neutron Spectroscopy NA-22 Quarterly Report FY 26 Q3

Aug, 2026

ORNL Report

ORNL HEP Self-Appraisal for FY2026

Aug, 2026

ORNL Report

HIGHER EFFICIENCY FISSION COUNTER FOR NEUTRON DETECTION

Fission chambers containing 235U have been used for detection of neutrons for many decades. In these chambers 235U is electroplated on a metal which is one plate of an ionization chamber. Since the range of fission products from induced fission in the chamber is extremely short, these deposits from electroplating are so thin that the amount of 235U results in low neutron d…

May, 2026

Journal

Associated particle imaging of neutron inelastic scatter: 3-D reconstruction, capabilities, and challenges

Associated particle imaging (API) offers unique advantages for 3-D imaging of neutron inelastic scatter, including single-view tomographic imaging and data acquisition when access is limited to only one side of the interrogated object. However, widespread adoption of neutron inelastic scatter imaging has been impeded by several inherent challenges, most prominently spatial…

May, 2026

ORNL Report

A Real-time Solution for Fast-neutron Spectroscopy NA-22 Quarterly Report FY 26 Q2

Mar, 2026

Conference Paper

Novel Cascaded Ring Oscillator Vernier based TDC Architecture with a Feedthrough Reference Oscillator

Time to digital converters (TDCs) are widely used in particle physics and medical imaging to determine the relative arrival time of photons and other particles. Vernier TDCs are one of the most attractive options due to their power consumption efficiency and their small footprint. We present our newly patented innovative architecture of cascaded-stage Vernier TDCs comprise…

Mar, 2026

ORNL Report

A Real-time Solution for Fast-neutron Spectroscopy NA-22 Quarterly Report FY 26 Q1

Nov, 2025

ORNL Report

Year 3 Report on TDC Performance and ASIC Tile Controller Design

The tile controller (TC) is a device that supports the readout of arrays of three-dimensional photon-to-digital converters (3D PDCs), and its presence is necessary whenever arrays of 3D PDCs are used. Its main function is to provide communication between 3D PDC chips and a data acquisition system. In particular, the TC will capture SPAD tagging and time of arrival informat…

Nov, 2025

ORNL Report

Year 3 Report on PDC Devices

The first three-dimensional photon-to-digital converters (3D PDCs) were created by vertically combining wafers obtained from the experimental “beta” run of Single-Photon Avalanche Diodes (SPAD) arrays at Teledyne DALSA with those of the digital readout obtained from a TSMC CMOS foundry run. The Teledyne-DALSA line is capable of producing excellent wafers of SPADs on specif…

Nov, 2025

Journal

X-Ray and Particle Detection With the Si(Li) Tracker Module of the GAPS Experiment

This work describes the architecture and the experimental results from the characterization of the lithium-drifted silicon (Si(Li)) detector module, which constitutes the building block of the tracker in the general antiparticle spectrometer (GAPS) experiment to search for dark matter. The instrument is designed for the identification of low-energy cosmic anti-nuclei (anti…

Oct, 2025

ORNL Report

Neutron Spectrometer Project NA-22 Quarterly Report (FY25Q4)