438 research outputs found
Constraints on Exotic Heavily Ionizing Particles from the Geological Abundance of Fullerenes
The C_{60} molecule exhibits a remarkable stability and inertness that leads
to its survival in ancient carbonaceous rocks initially subject to the high
temperatures requisite for its formation. Elementary particles having very high
electronic stopping powers can similarly form C_{60} and higher fullerenes in
their wake. Combined, these two features point at the possibility of using the
C_{60} presence (or absence) in selected bulk geological samples as a new type
of solid-state nuclear track detector, with applications in astro-particle
physics.Comment: Final version (few modifications). Phys. Rev. Lett. (in press). 4
pages LaTeX, 1 eps figure embedde
Towards Coherent Neutrino Detection Using Low-Background Micropattern Gas Detectors
The detection of low energy neutrinos ( few tens of MeV) via coherent
nuclear scattering remains a holy grail of sorts in neutrino physics. This
uncontroversial mode of interaction is expected to profit from a sizeable
increase in cross section proportional to neutron number squared in the target
nucleus, an advantageous feature in view of the small probability of
interaction via all other channels in this energy region. A coherent neutrino
detector would open the door to many new applications, ranging from the study
of fundamental neutrino properties to true "neutrino technology".
Unfortunately, present-day radiation detectors of sufficiently large mass (
1 kg) are not sensitive to sub-keV nuclear recoils like those expected from
this channel. The advent of Micropattern Gas Detectors (MPGDs), new
technologies originally intended for use in High Energy Physics, may soon put
an end to this impasse. We present first tests of MPGDs fabricated with
radioclean materials and discuss the approach to assessing their sensitivity to
these faint signals. Applications are reviewed, in particular their use as a
safeguard against illegitimate operation of nuclear reactors. A first
industrial mass production of Gas Electron Multipliers (GEMs) is succinctly
described.Comment: Presented at the 2002 IEEE Nuclear Science Symposium and Medical
Imaging Conference, Norfolk VA, November 10-16. Submitted to IEEE Tran. Nucl.
Sci. Five pages, eight figure
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