Harper Whitehouse - Academia.edu (original) (raw)
Papers by Harper Whitehouse
We consider a recently proposed mechanism for low energy nuclear reactions (LENRs). In this mecha... more We consider a recently proposed mechanism for low energy nuclear reactions (LENRs). In this mechanism the process is initiated by an external photon whose contribution is treated perturbatively. In the present paper we consider a related process that is induced by photon emission rather than absorption. We consider, as an example, fusion of hydrogen and deuterium to form He(3). This process, at leading order, proceeds by emission of a photon. In the present case we consider two photon emission and hence we need to go to the second order in perturbation theory. The emission of a high energy photon from the initial D-H system leads to the formation of an intermediate state which is a superposition of all energy eigenstates of the unperturbed Hamiltonian. We compute the cross section for such a reaction and show that, for suitable conditions in condensed matter medium, the reaction rate can be sufficiently large to be observable. © 2022 ISCMNS. All rights reserved. ISSN 2227-3123
This progress report appears in two parts. Part A is a summary of work done in support
2002 IEEE Position Location and Navigation Symposium (IEEE Cat. No.02CH37284)
Interference, whether intentional (jamming) or unintentional, both in-band and out-of-band, can b... more Interference, whether intentional (jamming) or unintentional, both in-band and out-of-band, can be a significant problem for receivers that operate in close proximity to high power transmitters. Out-of-band interference protection can be provided by high performance Radio Frequency (RF) filters used between the antenna and the receiver. These RF filters need to be low loss, have high out-of-band rejection and have nearly constant group delay to preserve the incoming signal characteristics. Well-designed superconducting filters can provide this level of performance and may also aid solutions for in-band interference, as the low loss of these devices allows their placement before the first Low-Noise Amplifier (LNA) in the system. We will summarize the results of experiments conducted with a set of electromagnetic HTS filters specially constructed for GPS frequency bands L1 and L2. We will also present recent data characterizing Lithium Niobate from room temperature to cryogenic temperatures. Although the temperature coefficient of delay of a Y-cut Z-propagating Lithium Niobate delay line is large at room temperature the coefficient of delay decreases as the temperature decreases until it becomes zero near 25K. Thus a combination of an ambient temperature quartz or Gallium Orthophosphate SAW bypass filter with either an HTS electromagnetic or an HTS Lithium Niobate SAW filter can provide linear phase filtering without impulse response ringing even in tactical applications.
MTT-S International Microwave Symposium Digest
A new surface acoustic wave delay line module is described which provides, for the first time, th... more A new surface acoustic wave delay line module is described which provides, for the first time, the ability to compute the real time Discrete Fourier Transform (DFT) with electronically variable bandwidth. Initial experiments with 12 and 32 tap PDC modules are described which demonstrated a 40 dB tap dynamic range and Fourier bandwidth variable from zero to beyond 10 MHz.
1973 Ultrasonics Symposium, 1973
Systolic arrays are formed by providing nearest-neighbor interconnections between a large number ... more Systolic arrays are formed by providing nearest-neighbor interconnections between a large number of elemental processors to form either a one or two dimensional array. With the possible exception of boundary elements, each processing element performs identical computations in synchronism with other elements in the array. Important problems for which systolic arrays hold potential are mentioned and the systolic array processor
The systolic array architecture is known to make highly efficient use of hardware in evaluating c... more The systolic array architecture is known to make highly efficient use of hardware in evaluating certain matrix products provided that the matrices are banded strongly. However, this high efficiency can be degraded significantly if the matrices to be processed do not possess the narrow bandwidth feature, but assume a more general structure. This paper introduces and evaluates two techniques which in some instances can enhance systolic array efficiency. The approach effectively reduces to adapting problem structure so that it more naturally fits the systolic array architecture. Potential benefits from this approach are quantified and presented in graphical form.
Time Frequency Signal Analysis, 1992
We consider a recently proposed mechanism for low energy nuclear reactions (LENRs). In this mecha... more We consider a recently proposed mechanism for low energy nuclear reactions (LENRs). In this mechanism the process is initiated by an external photon whose contribution is treated perturbatively. In the present paper we consider a related process that is induced by photon emission rather than absorption. We consider, as an example, fusion of hydrogen and deuterium to form He(3). This process, at leading order, proceeds by emission of a photon. In the present case we consider two photon emission and hence we need to go to the second order in perturbation theory. The emission of a high energy photon from the initial D-H system leads to the formation of an intermediate state which is a superposition of all energy eigenstates of the unperturbed Hamiltonian. We compute the cross section for such a reaction and show that, for suitable conditions in condensed matter medium, the reaction rate can be sufficiently large to be observable. © 2022 ISCMNS. All rights reserved. ISSN 2227-3123
This progress report appears in two parts. Part A is a summary of work done in support
2002 IEEE Position Location and Navigation Symposium (IEEE Cat. No.02CH37284)
Interference, whether intentional (jamming) or unintentional, both in-band and out-of-band, can b... more Interference, whether intentional (jamming) or unintentional, both in-band and out-of-band, can be a significant problem for receivers that operate in close proximity to high power transmitters. Out-of-band interference protection can be provided by high performance Radio Frequency (RF) filters used between the antenna and the receiver. These RF filters need to be low loss, have high out-of-band rejection and have nearly constant group delay to preserve the incoming signal characteristics. Well-designed superconducting filters can provide this level of performance and may also aid solutions for in-band interference, as the low loss of these devices allows their placement before the first Low-Noise Amplifier (LNA) in the system. We will summarize the results of experiments conducted with a set of electromagnetic HTS filters specially constructed for GPS frequency bands L1 and L2. We will also present recent data characterizing Lithium Niobate from room temperature to cryogenic temperatures. Although the temperature coefficient of delay of a Y-cut Z-propagating Lithium Niobate delay line is large at room temperature the coefficient of delay decreases as the temperature decreases until it becomes zero near 25K. Thus a combination of an ambient temperature quartz or Gallium Orthophosphate SAW bypass filter with either an HTS electromagnetic or an HTS Lithium Niobate SAW filter can provide linear phase filtering without impulse response ringing even in tactical applications.
MTT-S International Microwave Symposium Digest
A new surface acoustic wave delay line module is described which provides, for the first time, th... more A new surface acoustic wave delay line module is described which provides, for the first time, the ability to compute the real time Discrete Fourier Transform (DFT) with electronically variable bandwidth. Initial experiments with 12 and 32 tap PDC modules are described which demonstrated a 40 dB tap dynamic range and Fourier bandwidth variable from zero to beyond 10 MHz.
1973 Ultrasonics Symposium, 1973
Systolic arrays are formed by providing nearest-neighbor interconnections between a large number ... more Systolic arrays are formed by providing nearest-neighbor interconnections between a large number of elemental processors to form either a one or two dimensional array. With the possible exception of boundary elements, each processing element performs identical computations in synchronism with other elements in the array. Important problems for which systolic arrays hold potential are mentioned and the systolic array processor
The systolic array architecture is known to make highly efficient use of hardware in evaluating c... more The systolic array architecture is known to make highly efficient use of hardware in evaluating certain matrix products provided that the matrices are banded strongly. However, this high efficiency can be degraded significantly if the matrices to be processed do not possess the narrow bandwidth feature, but assume a more general structure. This paper introduces and evaluates two techniques which in some instances can enhance systolic array efficiency. The approach effectively reduces to adapting problem structure so that it more naturally fits the systolic array architecture. Potential benefits from this approach are quantified and presented in graphical form.
Time Frequency Signal Analysis, 1992