177 research outputs found
In Orbit Performance of the MAXI/SSC onboard the ISS
We report here the in orbit performance of the CCD camera (MAXI/SSC) onboard
the International Space Station (ISS). It was commissioned in August, 2009.
This is the first all-sky survey mission employing X-ray CCDs. It consists of
32 CCDs each of which is 1 inch square. It is a slit camera with a field of
view of 1deg.5x 90deg and scans the sky as the rotation of the ISS. The CCD on
the SSC is cooled down to the working temperature around -60degC by the
combination of the peltier cooler, a loop heat pipe and a radiator. The
standard observation mode of the CCD is in a parallel sum mode (64-binning).
The CCD functions properly although it suffers an edge glow when the Sun is
near the field of view (FOV) which reduces the observation efficiency of the
SSC down to about 30%. The performance of the CCD is continuously monitored
both by the Mn-K X-rays and by the Cu-K X-rays. There are many sources
detected, not only point sources but extended sources. Due to the lack of the
effective observation time, we need more observation time to obtain an extended
emission analysis extraction process.Comment: 15 pages 11 figure
Studies on Pheromones of Female Eri-Silk Moth, II. Preparation of Some Conjugated C₁₆-C₁₇ Alkadienals and Comparison of Them with the Pheromone by GLC
Article信州大学農学部紀要 20(1): 133-142(1983)departmental bulletin pape
Studies on Pheromones of Female Eri-Silk Moth, I. Preparation of C₆-C₁₁ 2-Alkenyl Triphenyiphosphonium Bromides
Article信州大学農学部紀要 20(1): 127-132(1983)departmental bulletin pape
Studies on Pheromones of Female Eri-Silk Moth, III. Synthesis of (6Z, 11Z)-6,11-Hexadecadienal and Its Activity as Pheromone Mimics toward Male Eri-Silk Moth
Article信州大学農学部紀要 20(2): 213-218(1983)departmental bulletin pape
Proton Irradiation Experiment for the X-ray Charge-Coupled Devices of the Monitor of All-sky X-ray Image mission onboard the International Space Station: I. Experimental Setup and Measurement of the Charge Transfer Inefficiency
We have investigated the radiation damage effects on a CCD to be employed in
the Japanese X-ray astronomy mission including the Monitor of All-sky X-ray
Image (MAXI) onboard the International Space Station (ISS). Since low energy
protons release their energy mainly at the charge transfer channel, resulting a
decrease of the charge transfer efficiency, we thus focused on the low energy
protons in our experiments. A 171 keV to 3.91 MeV proton beam was irradiated to
a given device. We measured the degradation of the charge transfer inefficiency
(CTI) as a function of incremental fluence. A 292 keV proton beam degraded the
CTI most seriously. Taking into account the proton energy dependence of the
CTI, we confirmed that the transfer channel has the lowest radiation tolerance.
We have also developed the different device architectures to reduce the
radiation damage in orbit. Among them, the ``notch'' CCD, in which the buried
channel implant concentration is increased, resulting in a deeper potential
well than outside, has three times higher radiation tolerance than that of the
normal CCD. We then estimated the charge transfer inefficiency of the CCD in
the orbit of ISS, considering the proton energy spectrum. The CTI value is
estimated to be 1.1e-5 per each transfer after two years of mission life in the
worse case analysis if the highest radiation-tolerant device is employed. This
value is well within the acceptable limit and we have confirmed the high
radiation-tolerance of CCDs for the MAXI mission.Comment: 17 pages, 2 table, 12 figures. Accepted for publication of Japanese
Journal of Applied Physics. High resolution file is available from
http://wwwxray.ess.sci.osaka-u.ac.jp/~miyata/paper/proton_cti.pd
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