Triad National Security, LLC

Other

University of California

The United States of America As Represented by the Department of Energy

Martyn Thomas Swinhoe

Kiril Dimitrov Ianakiev

Metodi Iliev

James L Smith

Markus Peter Hehlen

Peter Brent Littlewood

Michael Browne

Jason Charles Lashley

Clair J Sullivan

Boian S Alexandrov

Adrienne LaFleur

John Paul Lestone

Ludwig Holzleitner

Andrea Favalli

Krastan B Blagoev

Improved, high count rate thermal neutron counters and electronics enabling new, higher measurement capabilities are disclosed. Next generationHe andB tubes may include an electronics package capable of operating at higher count rates and in higher gamma fields and providing more efficient use ofHe gas. Conventional detector systems may also be upgraded, providing a possible solution to measure spent nuclear fuel with high neutron efficiency previously not possible inU fission counter systems. Switching the number of tubes per amplifier allows use of the measured nuclear material for a calibration standard for dead time correction, increasing accuracy of neutron measurements systems. An optimized detector geometry and advanced electronics with double pulse filtering and a dual channel readout may be provided. A bipolar shaper may improve dead time, provide efficient detector use, reduce double pulsing, facilitate high count rate measurements, and allow remote threshold setting.

High count rate thermal neutron detectors and electronics

Devices/apparatuses are disclosed that include a photoemitting component, a photosensitive component deposited on the photoemitting component, a charge collection component, and a hollow enclosure for housing the photoemitting component, the photosensitive component, the charge collection component, or combinations thereof. Methods for making and using the apparatuses are also disclosed.

Scintillation detectors

Each pulse of a pulse sequence received from a neutron detector is set as a trigger pulse triggering a predefined gate, the multiplicity of pulses within this gate is determined, the pulse having triggered the gate is assigned to a multiplicity category corresponding to this multiplicity of pulses and the trigger-to-predecessor distances from the trigger pulse to pulses preceding the trigger pulse within a certain range in the pulse sequence are determined. The range within which one looks for predecessor pulses of each trigger pulse exceeds the dead time of the neutron detector. For each multiplicity category, the number of trigger pulses assigned thereto is determined. For each multiplicity category, one builds, based upon the trigger-to-predecessor intervals determined, a distribution in time after an arbitrary preceding pulse of trigger pulses assigned to that specific multiplicity category. Based upon the multiplicity-specific distribution, one estimates, for each multiplicity category, the number of trigger pulses lost due to neutron detector dead time that would have been assigned to the multiplicity category. When the estimated number of lost trigger pulses is known, the number of trigger pulses assigned to each multiplicity category is accordingly corrected. As trigger pulses could have been assigned to a wrong multiplicity category due to missing pulses inside the triggered gates, the number of trigger pulses assigned to each multiplicity category may additionally be corrected for that using a similar technique.

Neutron multiplicity counting

A neutron detector has a compound of lithium in a single crystal form as a neutron sensor element. The lithium compound, containing improved charge transport properties, is either lithium niobate or lithium tantalate. The sensor element is in direct contact with a monitor that detects an electric current. A signal proportional to the electric current is produced and is calibrated to indicate the neutrons sensed. The neutron detector is particularly useful for detecting neutrons in a radiation environment. Such radiation environment may, e.g. include gamma radiation and noise.

Semiconductor neutron detector

A detector for detecting neutrons and gamma radiation includes a cathode that defines an interior surface and an interior volume. A conductive neutron-capturing layer is disposed on the interior surface of the cathode and a plastic housing surrounds the cathode. A plastic lid is attached to the housing and encloses the interior volume of the cathode forming an ionization chamber, into the center of which an anode extends from the plastic lid. A working gas is disposed within the ionization chamber and a high biasing voltage is connected to the cathode. Processing electronics are coupled to the anode and process current pulses which are converted into Gaussian pulses, which are either counted as neutrons or integrated as gammas, in response to whether pulse amplitude crosses a neutron threshold. The detector according to the invention may be readily fabricated into single or multilayer detector arrays.

Neutron and gamma detector using an ionization chamber with an integrated body and moderator

Growing community of inventors

Los Alamos, NM, United States of America

Martyn Thomas Swinhoe