INFN
- Genova
CRYOGENIC DETECTORS GROUP
EXPERIMENTAL ACTIVITIES
The group is involved in cryogenic
detectors development and in their application in Physics Experiments.
Main interest are several aspect
of Neutrino Physics.
Future application in space Astrophysics
are foreseen.
Our detectors are mainly intended
for High energy resolution spectroscopy: beta spectroscopy and X-ray spectroscopy.
The experiments on beta spectra
with an unprecedented energy resolution, to set new limits to neutrino
mass, require deep investigations on a number of effects involving atomic,
molecular and solid state physics.
Recently the modulation of the
187Re
beta spectrum due to the Crystal lattice was for the first time observed
[12].
This effect, Beta Environmental
Fine Structure (BEFS) or Koonin oscillations, is similar to the well known
EXAFS and might become a useful tool for solid state investigations.
Deeper investigation are neverthless
required to set accurate limits on neutrino mass.
RESEARCH
ACTIVITIES:
studies on thermalization processes in superconductors,
fabrication of transition edge thermometers,
low noise cryogenic electronics, squid electronics
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187Re
decay experiment to set new limits on neutrino mass
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Studies on E.C. processes, 7Be
ground state decay for a solar neutrino capture on Lithium experiment.
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IMXS: the proposal for an experiment
on the International Space Station that will perform an all sky survey
of the soft X-ray background for interstellar and intergalactic medium
studies has been submitted to the Italian Space Agency (ASI). The goal
of the experiment is to obtain spectroscopic information on the X-ray diffuse
background in the energy range 30-1000 eV. This information will address
many questions concerning the origin, composition, structure and evolution
of the interstellar and intergalactic medium.The detector will consist
of an array of cryogenic micro-calorimeters at a working temperature of
60 mK optimized for low energy X-rays, with an energy resolution of less
than 4 eV FWHM. The construction of the detector will be based on the experience
of the Wisconsin/Goddard sounding rocket program where silicon implanted
thermistor based detectors are used. The detector will be installed in
an adiabatic demagnetization refrigerator inserted in a superfluid He dewar.
The experiment will be installed on one of the outside mounting pallets
of the Space Station looking at the local zenith with a field of view of
10 degrees. The total life time required on the Space Station in order
to have good physical results ranges from a minimum of 1 year to a maximum
of 3 years; during this time one superfluid He transfer each 6-8 month
is necessary. The experiment will cover about 84% of the sky and in a three-year
life time on the space station will obtain statistics of about 20,000 counts
for a resolution element of 10 degrees.
LABORATORY
FACILITIES:
Cryostats:
Oxford 200 TLE dilution refrigerarator
Oxford Kelvinox dilution refrigerator.
Adiabatic demagnetization cryostats
Thin film fabrication systems:
Electron gun evaporation
Sputtering and thermal evaporation
Laser ablation deposition System
microlithography system.
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