Preliminary study for producing higher harmonic hard X-rays from weakly ionized nickel plasma

Satô, Eiichi; Hayasi, Yasuomi; Tanaka, Etsuro; Mori, Hiromu; Kawai, Toshiaki; Inoue, Takashi; Sato, Shigehiro; Takayama, K.; Onagawa, Jun; Ido, Hideaki

doi:10.1016/j.radphyschem.2005.11.012

Cited by 20 publications

(6 citation statements)

References 22 publications

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“…To perform soft radiography with photon energies below 150 keV, we have developed several different flash x-ray generators. In particular, a linear plasma flash x-ray generator [11][12][13][14] is very useful for producing low-photon-energy K-series characteristic x-rays of nickel, copper, and molybdenum. In the spectral measurement, we have confirmed the irradiation of clean K rays of nickel and copper from the axial direction of weakly ionized linear plasma.…”

Section: I1troductio1mentioning

confidence: 99%

Second harmonic x-ray irradiation from weakly ionized linear ferrum plasma

et al. 2008

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In the plasma flash x-ray generator, a 200 nF condenser is charged up to 50 kV by a power supply, and flash x-rays are produced by the discharging. The x-ray tube is a demountable triode with a trigger electrode, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Target evaporation leads to the formation of weakly ionized linear plasma, consisting of ferrum ions and electrons, around the fine target, and intense K-series characteristic x-rays are produced from the plasma axial direction. At a charging voltage of 50 kV, the maximum tube voltage was almost equal to the charging voltage of the main condenser, and the peak current was about 15 kA. In the spectral measurement, Kβ rays were intense, and higher harmonic x-rays were observed. The pulse widths were 0.5 μs, and the maximum x-ray intensity was approximately 300 μGy.

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Section: I1troductio1mentioning

confidence: 99%

Second harmonic x-ray irradiation from weakly ionized linear ferrum plasma

et al. 2008

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“…However, because it is not easy to obtain sufficient machine times for angiography, we have developed a cerium X-ray generator 3,4) that can generate K¡ photons with an average energy of 34.6 keV. In addition, we have developed several monochromatic flash X-ray generators [5][6][7][8] to carry out high-speed monochromatic radiography with X-ray durations shorter than 1 µs. Nowadays, monochromatic imaging can also be performed utilizing photon-energy dispersion, and several detectors have been developed to realize specific objectives.…”

Section: Introductionmentioning

confidence: 99%

Investigation of dual-energy X-ray photon counting using a cadmium telluride detector and two comparators and its application to photon-count energy subtraction

Hagiwara

Satô

Watanabe

et al. 2014

Jpn. J. Appl. Phys.

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To obtain two tomograms with two different photon energy ranges simultaneously, we have performed dual-energy X-ray photon counting using a cadmium telluride (CdTe) detector, two comparators, two frequency-voltage converters (FVCs), and an analog digital converter (ADC). X-ray photons are detected using the CdTe detector with an energy resolution of 1% at 122 keV, and the event pulses from a shaping amplifier are sent to two comparators simultaneously to regulate two thresholds of photon energy. The logical pulses from a comparator are sent to an FVC consisting of two integrators, a microcomputer, and a voltage-voltage amplifier. The smoothed outputs from the two FVCs are input to the ADC to carry out dual-energy imaging. To observe contrast variations with changes in threshold energy, we performed energy-dispersive computed tomography utilizing the dual-energy photon counting at a tube voltage of 70 kV and a current of 25 µA. Two tomograms were obtained simultaneously at two energy ranges of 20.0-70.0 keV and 33.2-70.0 keV. The photon-count subtraction was carried out using photon energies ranging from 20.0 to 33.2 keV. The maximum count rate was 5.4 kilocounts per second with energies of 20.0-70.0 keV, and the exposure time for tomography was 10 min.

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“…In particular, plasma flash X-ray generators [1][2][3] have been developed to produce clean K-series characteristic X-rays because weakly ionized plasma plays an important role in absorbing bremsstrahlung X-rays.…”

Section: Introductionmentioning

confidence: 99%

Energy-Discriminating Gadolinium K-Edge X-ray Computed Tomography System

Miyata

Watanabe

Satô

et al. 2010

Jpn. J. Appl. Phys.

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An energy-discriminating K-edge X-ray computed tomography (CT) system is useful for increasing the contrast resolution of a target region utilizing contrast media and for reducing the absorbed dose for patients. The CT system is of the first-generation type of detector using cadmium telluride (CdTe). CT is performed by repeated translations and rotations of an object. Penetrating X-ray photons from the object are detected by a CdTe detector, and event signals of X-ray photons are produced using charge-sensitive and shaping amplifiers. Both photon energy and energy width are selected out using a multichannel analyzer, and the number of photons is counted by a countercard. To perform energy discrimination, a low-dose-rate X-ray generator for photon counting was developed. Its maximum tube voltage and minimum tube current were 110 kV and 1 mA, respectively. In energy-discriminating CT, the tube voltage and tube current were 100 kV and 20 mA, respectively, and the X-ray intensity was 2.98 mGy/s at a distance of 1.0 m from the source and a tube voltage of 100 kV. The demonstration of enhanced gadolinium K-edge X-ray CT was carried out by selecting photons with energies just beyond the gadolinium K-edge energy of 50.3 keV.

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Preliminary study for producing higher harmonic hard X-rays from weakly ionized nickel plasma

Cited by 20 publications

References 22 publications

Second harmonic x-ray irradiation from weakly ionized linear ferrum plasma

Second harmonic x-ray irradiation from weakly ionized linear ferrum plasma

Investigation of dual-energy X-ray photon counting using a cadmium telluride detector and two comparators and its application to photon-count energy subtraction

Energy-Discriminating Gadolinium K-Edge X-ray Computed Tomography System

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