20 research outputs found
Information heat engine: converting information to energy by feedback control
In 1929, Leo Szilard invented a feedback protocol in which a hypothetical
intelligence called Maxwell's demon pumps heat from an isothermal environment
and transduces it to work. After an intense controversy that lasted over eighty
years; it was finally clarified that the demon's role does not contradict the
second law of thermodynamics, implying that we can convert information to free
energy in principle. Nevertheless, experimental demonstration of this
information-to-energy conversion has been elusive. Here, we demonstrate that a
nonequilibrium feedback manipulation of a Brownian particle based on
information about its location achieves a Szilard-type information-energy
conversion. Under real-time feedback control, the particle climbs up a
spiral-stairs-like potential exerted by an electric field and obtains free
energy larger than the amount of work performed on it. This enables us to
verify the generalized Jarzynski equality, or a new fundamental principle of
"information-heat engine" which converts information to energy by feedback
control.Comment: manuscript including 7 pages and 4 figures and supplementary material
including 6 pages and 8 figure
Development of an automatic observation system for Fabry-Perot interferometers
The importance of automatic observation systems for ground-based optical instruments is increasing since clustered measurements are being made with only a few operators. We have developed an automatic observation system for use with both a scanning and an all-sky Fabry-Perot interferometer. This paper describes the optical system of the instrument, its performance when observing auroras, and the details of the automatic observation system. The S/N ratio of the observed fringe exceeds 500, even if the auroral activity is low. Using the Internet or telephone lines, an operator can monitor and control multiple optical instruments from a remote site. In addition, we introduce a new analysis software for estimating the emission intensity, wind velocity and temperature. Once the system is further improved by modifying it to enable radio communication, the construction of remote-controlled, relocatable observatories will become feasible, representing a remarkable evolution in optical measurement technology
Calibration of Photomultiplier Tubes for the Fluorescence Detector of Telescope Array Experiment using a Rayleigh Scattered Laser Beam
We performed photometric calibration of the PhotoMultiplier Tube (PMT) and
readout electronics used for the new fluorescence detectors of the Telescope
Array (TA) experiment using Rayleigh scattered photons from a pulsed nitrogen
laser beam. The experimental setup, measurement procedure, and results of
calibration are described. The total systematic uncertainty of the calibration
is estimated to be 7.2%. An additional uncertainty of 3.7% is introduced by the
transport of the calibrated PMTs from the laboratory to the TA experimental
site.Comment: 43 pages, 15 figure
Possible interpretations of the joint observations of UHECR arrival directions using data recorded at the Telescope Array and the Pierre Auger Observatory
Development of Fabry-Perot interferometers for airglow observations
We are developing an all-sky and a scanning Fabry-Perot interferometer for studying the dynamics of the thermosphere and the mesosphere in the polar region. Our instruments have three unique features useful for airglow observation; (1) Each instrument can obtain interference fringes at two different wavelengths at a time using a dichroic mirror, (2) The instruments can observe very weak airglow with the aid of a photon counting imager, (3) When operated simultaneously, the all-sky and the scanning Fabry-Perot interferometer can observe vertical winds in addition to two-dimensional atmospheric motions. We have made two test observations at the Zao observatory, Tohoku University in 1994,and at the Shigaraki observatory, Kyoto University in 1995
Manufacturing and welding assembly of the vacuum vessel on JT-60SA
The JT-60SA Vacuum Vessel (VV) was manufactured as the 10 sectors split in the factory and these sectors were weld-assembled as the 360-degree torus with the design offset value of the weld shrinkage. The dimensions as the 10 m scale torus were well controlled regardless of the thin wall thickness of 18 mm and a large amount of welding line due to the double wall structure and 72 port penetrations. The final VV 20-degree sector was installed into the 340-degree sector of the tokamak with the TF coil and the VV Thermal Shield, and the VV was weld-jointed as a torus. This paper reports the design concept to reduce the safety factor and welding amount to achieve the dimension specified, and the result of the VV manufacturing
Search for molecular bremsstrahlung radiation signals in Ku band with coincidental operations of radio telescopes with air shower detectors
Microwave radiation from extensive air showers is expected to provide a new technique to observe UHECR. We insatlled and operate radio telescopes in Osaka and at Telescope Array site in Utah, USA. In Osaka, we are coincidentally operating two Ku band radio telescopes with an air shower array which consists of nine plastic scintillators with about 10 m separation. In Utah, we installed two telescopes just beside the Black Rock Mesa fluorescence detector (FD) station of the Telescope Array experiment, and we operated the radio telescopes coincidentally with FD event triggers. We report the experimental setups and the results of these measurements