Zobrazeno 1 - 10
of 66
pro vyhledávání: '"Allen N. Garroway"'
Publikováno v:
Applied Magnetic Resonance. 25:485-500
The fictitious spin-1/2 operators are well known to describe the evolution of a pure nuclear quadrupole resonance (NQR) system; particularly, the application of a radio-frequency pulse at one of the NQR transition frequencies is equivalent to a three
Autor:
Joel B. Miller, Allen N. Garroway
Publikováno v:
Applied Magnetic Resonance. 25:475-483
The application of nuclear quadrupole resonance (NQR) to the detection of materials can be hampered by the low sensitivity of the technique. The use of surface coils for remote detection only exacerbates this problem. In this paper we demonstrate the
Autor:
Allen N. Garroway, Bryan H. Suits
Publikováno v:
Journal of Applied Physics. 94:4170-4178
A computational method for optimizing both single- and two-layer surface coils is presented that is relatively easy to implement in practice using either a variational approach or through standard numerical matrix diagonalization techniques. The tech
Publikováno v:
Solid State Nuclear Magnetic Resonance. 24:123-136
Nitrogen is prevalent in many materials, both naturally occurring and man-made. In particular, it is found in many explosives and other contraband materials. One technique for the detection of such materials in the field is the use of the magnetic re
Publikováno v:
The Journal of Chemical Physics. 118:5071-5081
We demonstrate, theoretically and experimentally, that the irradiation of a powder sample containing spin-1 nuclei by two of the three characteristic nuclear quadrupole resonance (NQR) frequencies can result in several echo signals at the third NQR f
Publikováno v:
Journal of Magnetic Resonance. 151:228-234
The low sensitivity of nuclear quadrupole resonance (NQR) of powders is due, in part, to the inability to efficiently excite and detect nuclei at all crystal orientations. Here we describe the use of circularly polarized RF magnetic fields for excita
Publikováno v:
Chemical Physics Letters. 342:362-368
We introduce a new nuclear quadrupole resonance (NQR) method for the detection of spin-1 nuclei, where the transition excited and directly detected is not irradiated at all. It is demonstrated, theoretically and experimentally, that the irradiation o
Autor:
Joel B. Miller, R. Matthews, A.D. Hibbs, G.A. Barrall, Allen N. Garroway, Bryan H. Suits, L.J. Burnett, M. L. Buess
Publikováno v:
IEEE Transactions on Geoscience and Remote Sensing. 39:1108-1118
Detection of explosives has the flavor of those mathematical problems that are not invertible. It is easier to hide explosives than to find them. Many approaches have been proposed and executed for the remote detection of explosives, contraband mater
Autor:
Allen N. Garroway
Publikováno v:
Magma: Magnetic Resonance Materials in Physics, Biology, and Medicine. 9:103-108
The contributions of Sir Peter Mansfield to MRI are rooted in solid state NMR. I summarize some of the important contributions of Sir Peter to that field, provide a glimpse of the state of the art in multiple-pulse line-narrowing in the early 1970s,
Publikováno v:
Journal of Magnetic Resonance. 135:373-379
The use of surface coils in magnetic resonance is widespread. Examples include MRI, detection of subsurface aquifers by NMR, and, more recently, landmine detection by nuclear quadrupole resonance. In many of these cases a finite-sized sample to be ex