No abstract available

No abstract available

No abstract available

[en] Disclosed is a small portable extremely rugged charger for existing pocket-sized type radiation dosimeters. The charger is comprised of a rectangularly shaped housing which contains a piezoelectric charging circuit which is manually operated by a handle to produce a relatively high charging voltage. The charging voltage is coupled to a charging post mounted on a removable cover which is adapted to be selectively rotated so that the underside of the charging post is exposed to light from one of two light windows in the housing whereupon the dosimeter scale may be viewed by either direct or reflected light from any source available. The piezoelectric charging circuit is comprised of a pair of axially aligned cylinders of piezoelectric material mounted in a fulcrum type frame having a beam lever element in contact with one of the cylinders. A spring bias element is connected to the beam lever element and is actuated by a cam attached to the handle which when rotated acts upon the spring to cause an axial compressional force to be applied to the cylinders which thereby produce the required charging voltage

No abstract available

[en] The reactor thermalhydraulic tast loop permits to study experimentally the thermalhydraulic phenomena in a PWR or PHWR nuclear reactor. The system is design to operate in normal mode, hence the power supplied to the test section will loose totally as soon as the system is shutdown. In this research, the power control system has been modified in order to be able to simulate the decay heat phenomena. The power setting circuit has been modified from the potentiometer circuit to another one using DAC and computer program. This modification is to overcome the slow setting changes caused by the limit of the motor rotation. The test results an absolute error 6.25 kW, that corresponds to the DAC conversion error 0.5 LSB. This error is less than any other general method, that provides error conversion 1 LSB. In term of electrical power, the error value depends on the setting configuration adapted to the maximum power. In this work, the maximum power value is 3.2 MW, which corresponds to the nominal power of the installation. Besides its better precision, this modification provides also a higher speed then the previous system using potentiometer. The smallest sampling time chosen 10 ms is much greater then the DAC time conversion, so the analog signal still well correspond to its digital value

No abstract available

No abstract available

[en] A modification of a commercial electrostatic voltmeter which operates on the Kelvin--Zisman principle is described which permits operation inside a vacuum system at pressures below 5.0 x 10^-8 Torr. This allows for in-vacuum electrostatic measurements of voltages of up to 5 kV

[en] The potential difference between two floating probes placed in a dc discharge in a magnetic field was measured as a function of the distance between them. When the two probes approach closer to each other, the potential difference behaves as if there were an electric field in the inverse direction. Its dependence on the pressure, the magnetic field and the dc discharge current is studied and the experimental region where this anomaly occurs is shown. A discussion is provided on the relation between the apparently anomalous electric field and the disturbance of the plasma column by the probes. (author)