Abstract: A three-axis radiation detection system whose inner and outer electrodes are shaped and positioned so that the shortest path between any point on the inner electrode and the outer electrode is a different length whereby the rise time of a pulse derived from a detected radiation event can uniquely define the azimuthal and radial position of that event, and the outer electrode is divided into a plurality of segments in the longitudinal axial direction for locating the axial location of a radiation detection event occurring in the diode.

Abstract: A method for improving the speed of convergence to sub-least-significant-bit accuracy and precision in a digital signal averager when the measurements are averaged over many samples where the noise inherent in the signal is not large compared to 1 LSB. A slider offset circuit implements the method which adds offsets to an analog input signal acquired from an analog sensor. The slider offset circuit compensates for limitations in the resolution of an analog-to-digital converter by adding a sub-least-significant-bit offset to the input signal. Similarly, the slider offset circuit compensates for the differential non-linearity using a Gatti offset which are whole number multiples of the average voltage bin width. Speed of convergence to sub-LSB accuracy is further improved by employing non-consecutive increments in the two sliders.

Abstract: A method and apparatus for compression and filtering of data associated with spectrometry. The method and apparatus serves to recognize peak events and filter data associated with background noise, thereby reducing the volume of data to be transferred to storage and the data transfer rate required for storing the desired data. The method of the present invention monitors the value of each data point as it is encountered and compares it to the previously encountered data to determine whether it is on or very near a peak. The y values for each data point are continuously summed and averaged to determine the average background level. The deviation .delta..sub.i is determined for each subsequent data point and is used to determine a threshold. Each subsequent data point is compared to the threshold and, if found to be above the threshold, is assumed to be part of or very near a peak. At this point, the averaging is stopped until a subsequent data point is determined to be below the threshold.

Abstract: A digital gated base line restorer system for an ionizing radiation spectroscopy device includes a gated base line restorer circuit, responsive to pulses passing through the device, for generating a weighted average of previous base line sample points and applying it to the pulses to compensate for base line offset errors; and a control circuit responsive to the pulses passing through the device, to enable the gated base line restorer circuit to generate the weighted average during intervals between the pulses and applying it during the random pulses.

Abstract: A time analyzer having an improved interpolator with temperature compensation. The time analyzer of the present invention can be operated in a wide range of temperatures without need of recalibration in the field. The device includes hardware for making a coarse time measurement. A fine time measurement is obtained by interpolating within a cycle of the master clock. A temperature correction look up table is produced which incorporates information unique to each analyzer. Information stored in the look up table of each instrument is used to correct time measurement for enhanced precision.

Abstract: An automatic pole-zero adjustment circuit for an ionizing radiation spectroscopy system includes a digital conversion circuit, responsive to random analog pulses passing through the system for converting the random analog pulses to digital pulses; a programmable digital shaping filter including means for applying a pole-zero cancellation adjustment to compensate for under/overshoot at the output of the programmable digital shaping filter; digitally programmable sampling means including means for defining a window for sampling the trailing edge of the digital pulses and means for sampling the digital pulses during that window to determine the presence of undershoot or overshoot; and a digitally programmable control circuit, responsive to the pole-zero sampling means, for driving the programmable digital shaping filter to introduce an under/overshoot correction signal to the digital programmable shaping filter.

Abstract: An automatic pulse top optimization circuit for an ionizing radiation spectroscopy system includes a conversion circuit, responsive to random analog input pulses passing through the system, for converting the random analog pulses to digital pulses; a programmable shaping filter, responsive to the digital pulses, for producing an output of predetermined shape which maximizes the precision and accuracy of the anticipated measurement; pulse shape sampling means including means for defining a window for sampling the top of the pulse and means for sampling the pulses during that window to determine the presence of a deviation from the predetermined shape; and a control circuit, responsive to the pulse shaped sampling means, for programming the programmable shaping filter to compensate for a deviation in the predetermined shape.

Abstract: An radiation detection system whose inner and outer electrodes are shaped and positioned so that each path between them is a different length is a different length whereby the rise time of a pulse derived from a detected radiation event can uniquely define the azimuthal and radial position of that event.

Abstract: The segmented electrode radiation detector includes a semiconductor diode; an internal recess having a decreasing cross-sectional area extending at least partially axially into the diode. The plurality of inner electrode segments disposed axially spaced from each other on the surface of the recess and electrically isolated from each other for defining a plurality of axially discrete detection zones.