Thermal experiment of silicon PIN detector

The experiment of this paper is the thermal test of the leakage current of silicon PIN detector. Raising temperature may cause the detector to increase leakage current, decrease depletion and increase noise. Three samples are used in the experiment. One (called ΔE) is the sample of 100 μm in thickness. The other two (called E₁ and E₂) are stacks of five detectors of 1000 μm in thickness. All of them are 12 mm in diameter. The experiment has been done for 21 hours and with power on continuously. The samples have undergone more than 60℃ for about one hour. They are not degenerated when back to the room temperature. The depletion rate is temperature and bias voltage related. With the circuit of the experiment and temperature at 35℃, ΔE is still depleted while E₁ and E₂ are 94.9% and 99.7% depleted respectively. The noises of the samples can be derived from the values at room temperature and the thermal dependence of the leakage currents. With the addition of the noise of the pre-amplifier, the noises of E₁, E₂ and ΔE at 24℃ are 16.4, 16.3, and 10.5 keV (FWHM) respectively while at 35℃ are about 33.6, 33.1, and 20.6 keV (FWHM) respectively.     

Geomagnetic responses in high latitudes during the storm of July 15-16, 2000

The ionospheric equivalent currents in the high latitudes and the auroral electrojet system during the geomagnetic storm on July 15-16, 2000 are analyzed by using geomagnetic data from IMAGE chain. The large-scale vortices of equivalent currents are observed in the storm. The vortices on the dusk side of ionosphere correspond to four-celled pattern of plasma convection associated with NBZ, region I and region II field-aligned currents. Only one vortex can be found on the dawn side of ionosphere after interplanetary magnetic field (IMF) turns southward. In the initial phase of the storm, the center of eastward electrojets tends to shift equatorward. It arrives at 58.62o latitude of corrected geomagnetic coordinates (CGM). The westward electrojets are strong in the main phase. The center of westward electrojets in this period moves equatorward and may be beyond the southernmost station (56.45°) of the chain.