Measurement of Negative Ions in the D-Layer by a Sounding Rocket.

Abstract

The result of observations on the D-layer by the S-310-20 rocket, which was launched from the Kagoshima Space Center (KSC) at 4:30 am in January 28, 1990, is presented. A Faraday cup with a grid and a collector was used to measure the currents of charged particles of both signs. The saturation currents at positive and negative biases are found to be of a comparable order up to 85 km. It is deduced from the data analysis by considering the rocket velocity and precession that in the D-layer the ratio of the negative to the positive ion density is 80-88% at heights lower than 82 km and decreases with height above 82 km toward the E-layer. The effective negative ion density is nearly constant below 74 km, increases from 102 to 103 CM -3 toward 85 km, and then decreases toward the E-layer.

Measurement of Negative Ions in the Lower Ionosphere (D-Layer) in the Polar Region.

“…Figure 2 shows the ion current 1+ at the negative bias and the ratio R of the current 1e at positive bias to I+ (R = III+) vs. height h. The best fitted curve is drawn for R while a curve for making it easy to see the data is drawn for I+. The notation of R here is different from that of the previous paper (Amemiya and Nakamura, 1993) in that the current at positive bias is essentially contributed by electrons and the contribution of negative ions is negligible. The figure shows roughly the E-layer peak at about 100 km.…”

“…Details on the method of data analysis, including effective masses of positive and negative ions vs. height and the effect of the angle against the flight velocity, were given previously (Amemiya and Nakamura, 1993). For the data analysis, it was shown there that the effective mass numberM+etrofpositive ions is important, where M+,ff ' = E1 {/3/M 1V2 }2; /3j is the content ratio of each ion.…”

“…The method for measuring negative ions is similar to that of S-310-20 rocket (Amemiya and Nakamura, 1993) which was launched on Jan. 28, 4h30m (JST), 1990, at Kagoshima Space Center (KSC) in Uchinoura (31.15°N, 131.08°E). Figure 1 shows the relation of the height h vs. ranger of the S-310-22 rocket.…”

“…In our previous observation ofthe E region by a Langmuir probe (Amemiya et al,1985), there was a little trace of negative ions in the second derivative of the probe characteristics at lower regions but data were not accurately taken below 80 km. Our recent experiment in Japan by using a Faraday cup (Amemiya and Nakamura, 1993) showed that the negative ion-layer extended from about 60 km toward the height near 90 km. The upper boundary was higher than that in the polar region.…”

Review of in-space plasma diagnostics for studying the Earth’s ionosphere

“…V min = 1 2 m i q v 2 s . For the species that make up the ionosphere, O 2 is the heaviest molecule that can generate negative ions [64]; therefore V min should be at least about −10.5 V (i.e. for v s = 7.8 km s −1 , i.e.…”