Simultaneous measurements of X-rays and electrons during a pulsating aurora

Abstract

Abstract. The PULSAUR II rocket was launched from Andùya Rocket Range at 23.43 UT on 9 February 1994 into a pulsating aurora. In this paper we focus on the observations of precipitating electrons and auroral X-rays. By using models it is possible to deduce the electron energy spectrum from X-ray measurements. Comparisons are made between the deduced electron uxes and the directly measured electron¯uxes on the rocket. We found the shape of the observed and the deduced electron spectra to ®t very well, with almost identical e-folding energies in the energy range from 10 ke V to $ 60±80 ke V. For the integrated¯uxes from 10.8 to 250 ke V, we found a discrepancy of 30% . By combining two models, we have found a good method of deducing the electron precipitation from X-ray measurements. The discrepancies between calculations and measurements are in the range of the uncertainties in the measurements.

Energetic Electrons Precipitating at High Latitudes: PEEL Data from HotPay-2 Mission

“…The three increases marked in Fig. (5) have the following energy spectra composition and downward to upward ratio at the low energies as shown in Figs. (7)(8)(9).…”

“…Using the geometrical factor 0.077 cm 2 .sr of the PEEL and assuming the e-folding energy of the order of 10 keV and higher energy threshold of PEEL with respect to the detector described in [4], the highest pulse (event 1 in Fig. 5) gives the value >10.8 keV electrons of the order of 2.10 6 which is by factor ~10 lower than what is observed during the strong geomagnetic activity [5]. The rocket campaign took place when auroral activity appeared after a long geomagnetically quiet period.…”

“…The values presented in Fig. (5) should be multiplied just by factor 13 to obtain the estimates of flux in units (cm 2 .s.sr) -1 .…”

“…The energetic electrons precipitating into the atmosphere are subject of study for long time (e.g. [1][2][3][4][5][6] among others). The fine structure of the electron fluxes at high latitudes within the local loss cone was observed e.g.…”

“…Fig (5). presents the plot of 1 sec sums of counting rate of detector 1 in the channels 1-4 during the flight.…”