Proc 3rd ESA Workshop on millimetre wave technology and
applications (ESPOO, 21-23 May 2003), Page 69 The LFI (Low Frequency Instrument) on board the ESA Planck satellite is
constituted by an array ...of radiometric detectors actively cooled at 20 K in the
30-70 GHz frequency range in the focal plane of the Planck telescope. In this
paper we present an overview of the LFI instrument, with a particular focus on
the radiometer design. The adopted pseudo-correlation scheme uses a software
balancing technique (with a tunable parameter called gain modulation factor)
which is effective in reducing the radiometer susceptibility to amplifier
instabilities also in presence of small non-idealities in the radiometric chain
components, provided that the gain modulation factor is estimated with an
accuracy of the order of 0.2%. These results have been recently confirmed by
experimental laboratory measurements conducted on the LFI prototype radiometers
at 30, 70 and 100 GHz.
The LFI (Low Frequency Instrument) on board the ESA Planck satellite is constituted by an array of radiometric detectors actively cooled at 20 K in the 30-70 GHz frequency range in the focal plane of ...the Planck telescope. In this paper we present an overview of the LFI instrument, with a particular focus on the radiometer design. The adopted pseudo-correlation scheme uses a software balancing technique (with a tunable parameter called gain modulation factor) which is effective in reducing the radiometer susceptibility to amplifier instabilities also in presence of small non-idealities in the radiometric chain components, provided that the gain modulation factor is estimated with an accuracy of the order of 0.2%. These results have been recently confirmed by experimental laboratory measurements conducted on the LFI prototype radiometers at 30, 70 and 100 GHz.
A 160KV DEUTERIUM THYRATRON CROWBAR UNIT Judd, D.A.; Kettle, L.J.; Menown, H. ...
Twentieth Conference Record on Power Modulator Symposium,
1992
Conference Proceeding
We have studied the time-of-flight spectra of neutrons produced by the charge-exchange reaction {pi}{sup {minus}}{ital p}{r arrow}{pi}{sup 0}{ital n} of {pi}{sup {minus}}{ital p} atoms in liquid ...hydrogen, at flight distances up to 18.1 m. We have found the neutron velocity for {pi}{sup {minus}}{ital p} atoms at rest to be 0.894 266{plus minus}0.000 063 cm/ns, corresponding to a pion mass difference {ital m}{sub {pi}}{sup {minus}}{minus}{ital m}{sub {pi}}{sup 0}=4.593 64{plus minus}0.000 48 MeV. As an additional result, we have observed a broadening of the neutron time-of-flight peak with increasing flight distance, which implies that the kinetic-energy distribution of the {pi}{sup {minus}}{ital p} atoms just before the charge-exchange reaction has one component extending up to {similar to}1 eV and another component extending up to {similar to}70 eV; each component contains about half of the {pi}{sup {minus}}{ital p} atoms.
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