| Project/Area Number |
04805005
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
物理計測・光学
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| Research Institution | Tottori University |
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Principal Investigator |
HARADA Hisamochi Tottori Univ., Faculty of Engng., Assoc.Prof., 工学部, 助教授 (80032275)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1993: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1992: ¥900,000 (Direct Cost: ¥900,000)
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| Keywords | Mossbauer spectroscopy / Hadamard Transform / digital signal processing / アダマール変換 / メスバウアー分光学 |
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| Research Abstract |
In Mossbauer spectroscopy, the intensity of gamma rays from the source is weak as compared with other spectroscopies. We studied by computer simulation the effects of Hadamard transform which can be used to decrease the time required in measurement of weak Mossbauer pectre. Parameters of Lorentzian spectra containe noises were estimated by the least-square method to compare Hadamard transformed measurement with ordinary one.
In simulation by using Hadamard transform 4 to 512 order, we obtained some results : a) the decrease of the standard deviation of the noise in the spectra is dependent on Hadamard matrix order. b) In weak spectra, the differences between estimated values and original parameters show half values of that non Hadamard transformed spectra. c) Suitable mask order should be selected in relation to half-width of spectra.
An Hadamard type Mossbauer spectrometer was designed to use gamma rays modulated by Doppler velocity Vcosrheta in addition to V.Slits of Hadamard masks were constructed in a concentric configuration and set on the optical axis between the source and the absorber. In this plan, it became clear that the source intensities of linearly modulated gamma rays are dependent on the measurement channel. Therefore, an apparatus with fixed slits can be realized when low order masks are used. For applications of this type Hadamard spectrometer, there are some difficlut probrems to be solved.
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