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Titel |
Possible application of compact electronics for multilayer muon high-speed radiography to volcanic cones |
VerfasserIn |
H. K. M. Tanaka, I. Yokoyama |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
2193-0856
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Digitales Dokument |
URL |
Erschienen |
In: Geoscientific Instrumentation, Methods and Data Systems ; 2, no. 2 ; Nr. 2, no. 2 (2013-11-22), S.263-273 |
Datensatznummer |
250084925
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Publikation (Nr.) |
copernicus.org/gi-2-263-2013.pdf |
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Zusammenfassung |
Compact data-taking electronics were developed for high-speed multilayer
muon radiography in order to minimize operation failure rates. By
requiring a linear trajectory within the position sensitive detectors
(PSDs), the background (BG) events produced by vertical electromagnetic (EM)
showers are effectively reduced. In order to confirm the feasibility of this
method, the system comprising four PSD layers was tested by imaging the
internal structure of a parasitic cone and the adjacent craterlets formed in
the 1910 eruption at the base of the Usu volcano, Hokkaido with a conventional
(MURG08) readout system (Kusagaya et al., 2012; Uchida et al., 2009). The new
mountain is believed to be a cryptodome since its formation. As
knowledge on lava domes is accumulated at various volcanoes, the definition
of "cryptodome" is now doubted in its validity. The results of the
preliminary 290 h muon radiographic survey revealed that the
"cryptodome" is not underlain by any lava mass and that a main craterlet
is accompanied by magma intrusions at shallow depths. The former verifies
that the new mountain is not a cryptodome but a volcanogenetic mound, and
the latter interprets the phreatic explosions forming the craterlets as
intrusions of magma into the aquifer. However, a higher data taking failure
rate was observed with a software-based MURG08 system when the size of the
active area of the detection system was enlarged to improve the detection
ability of the system. The newly developed MURG12 is a complete electronics
system that can simultaneously process signals from 192 scintillation
counters with a data size of 600 kbps ch−1 without operation failure. We
anticipate that the observation speed would be further improved by employing
MURG12.
At the base of the Usu volcano, in the 20th century, four eruptions occurred. Some
of them demonstrated three characteristic stages of magma intrusions. First,
a magma branch remained at a depth leaving an upheaval of the ground;
second, it rose and reached aquifers causing phreatic explosions without
extrusions; and third, it reacted with aquifers causing phreatic explosions
and further extruded over the ground forming a lava dome. In order to
clarify the eruption mechanism of Usu, it is necessary for us to image many
parasitic cones. Based on the result of the test measurement, we anticipate
that MURG12 would be a strong tool for high-speed muon radiography. |
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