Mark Bauer

The K-shell Auger electron spectrum of gadolinium obtained using neutron capture in a solid state device

Highly doped or alloyed Gd2O3 in HfO2 films form heterojunction diodes with silicon. Single neutron capture events can be identified with a Hf0.85Gd0.15O1.93 to n-type silicon heterojunction. With long pulse integration times and suppression of the smaller pulses, there is agreement between the key pulse height spectral features and those predicted by Monte Carlo simulations. The latter align very well with the decay channels of the Gd following neutron capture, particularly those involving the Gd K-shell Auger electron resonances.

A Single Chip Computational Sensor System for Neutron Detection Applications

This paper presents the design and test results of a standalone computational radiation sensor system based on a single chip solution. A low-power sensor front end with a charge sensitive amplifier and an event driven analog-to-digital converter is integrated on the same chip as a dedicated microcontroller to process and bin the data from the neutron detector diode heterojunction according to pulse height. This combination effectively implements a single chip multichannel analyzer with the capability to do further processing of the data in software. The design was fabricated in a 0.18 μm CMOS technology with field tests demonstrating the validity of the approaches taken. The total system power consumption is 24 μW.

A single chip computational sensor system for gamma isotope identification

This paper presents the design and test results of a computational radiation sensor system based on a single chip solution that can perform standalone gamma isotope identification. A low power sensor front end with a charge sensitive amplifier, an event driven analog-to-digital converter, and a dedicated microcontroller are integrated on the same chip to process and bin the isotope data from a NaI gamma ray detector according to gathered pulse height. This combination effectively implements a single chip multichannel analyzer with the capability to do further processing of the data in software. To that end, a compact fixed-point program was developed to further analyze the pulse height spectra gathered from a variety of gamma ray sources and perform on-chip real-time gamma isotope identification. The design was fabricated in a 0.18 μm CMOS technology with field tests demonstrating the validity of the approaches taken. The total computational sensor system power consumption is less than 30 μW, excluding the detector power consumption. The gamma isotope identification program executes in 70 ms.

A directional gamma ray detector using a single chip computational sensor

This paper presents the design and test results of a computational radiation sensor system based on a single chip solution that can determine the direction of gamma rays emitted from a radiation source. The overall system is formed by merging a sensor section with a compact and low power computational radiation sensor section. The sensor section houses three NaI gamma ray detectors arranged in a spatial configuration that allows for direction finding. The computational sensor is based on a single chip solution developed by authors that houses multiple low power sensor front ends, event driven analog-to-digital converters, and a dedicated microcontroller on the same die. The presented system is capable of gathering the pulse height spectra from the gamma isotope data received from the three separate NaI detectors. Further processing of the data is possible by executing software algorithms using the computation resources available on chip. To that end, a compact fixed-point program was developed to perform on-chip real-time gamma ray collection and direction estimation. The single chip solution was fabricated in a 0.18 µm CMOS technology with field tests demonstrating the validity of the approaches taken. The total computational sensor system power consumption is less than 20 µW, excluding the detector power consumption. The gamma isotope direction finding program executes in less than 1 ms with 5° accuracy.

A computational sensor system for particle detection applications

This paper presents the design and testing results of a computational radiation sensor. The design utilizes a dedicated microcontroller to perform computation and data aggregation on the sensor head to reduce the information bit rate. A low-power charge sensitive amplifier and ADC complete the design. The design was implemented in a 0.35 µm CMOS technology with field tests demonstrating the validity of the approaches taken.

Video coding using 3 dimensional DCT and dynamic code selection

Summary only given. We address the quality issue, and present a method for improved coding of the 3D DCT coefficients. Performance gain is achieved through the use of dynamically selected multiple coding algorithms. The resulting performance is excellent giving a compression ratio of greater than to 100:1 for image reproduction. The process consists of stacking 8 frames and breaking the data into 8/spl times/8/spl times/8 pixel cubes. The three dimensional DCT is applied to each cube. Each cube is then scanned in each dimension to determine if significant energy exists beyond the first two coefficients. Significance is determined with separate thresholds for each dimension. A single bit of side information is transmitted for each dimension of each cube to indicate whether more than two coefficients will be transmitted. The remaining coefficients of all cubes are reordered into a linear array such that the elements with the highest expected energies appear first and lower expected energies appear last. This tends to group coefficients with similar statistical properties for the most efficient coding. Eight different encoding methods are used to convert the coefficients into bits for transmission. The Viterbi algorithm is used to select the best coding method. The cost function is the number of bits that need to be sent. Each of the eight coding methods is optimized for a different range of values.

The use of average mutual information profile as a species signature

Two sets of figures are presnted without discussion. The first show (1a): Average Mutual Information Profile for the Human Chromosomes plotted for values of k between 5 and 50; and b) Average Mutual Information Profile for the Mouse Chromosomes plotted for values of k between 5 and 50. Thesecond set of figures show: (2a) Average Mutual Information Profile for the C. Elegans Chromosomes plotted for values of k between 5 and 50; and b) Average Mutual Information Profile for the S. Cerevisiae Chromosomes plotted for values of k between 5 and 50.

A low-power 10-bit multichannel analyzer chip for radiation detection

This paper presents the design and test results of a low-power 10-bit multichannel analyzer (MCA) chip for radiation detection. A low-power and event driven charge sensitive front-end and analog-to-digital converter (ADC) are implemented together with a microcontroller on a single chip. This level of integration leads to a compact MCA that can process and build pulse height spectra when interfaced with a range of scintillator detectors, with the ability to digitally process the spectra using software running as embedded code. The design was fabricated in a 0.13 μm CMOS technology and tested to validate the approaches taken. The measured power consumption of the MCA is below 85 μW while detecting multiple radioisotopes.