Energy time dispersion of a new class of magnetospheric ion events observed near the Earth’s bow shock
We have analyzed high time resolution (≥6 s) data during the onset and the decay phase of several energetic (≥35 keV) ion events observed near the Earth’s bow shock by the CCE/AMPTE and IMP-7/8 spacecraft, during times of intense substorm/geomagnetic activity. We found that forward energy dispersion at the onset of events (earlier increase of middle energy ions) and/or a delayed fall of the middle energy ion fluxes at the end of events are often evident in high time resolution data. The energy spectra at the onset and the decay of this kind of events show a characteristic hump at middle (50–120 keV) energies and the angular distributions display either anisotropic or broad forms. The time scale of energy dispersion in the ion events examined was found to range from several seconds to ∼1 h depending on the ion energies compared and on the rate of variation of the Interplanetary Magnetic Field (IMF) direction. Several canditate processes are discussed to explain the observations and it is suggested that a rigidity dependent transport process of magnetospheric particles within the magnetosheath is most probably responsible for the detection of this new type of near bow shock magnetospheric ion events. The new class of ion events was observed within both the magnetosheath and the upstream region.
The onset phase of upstream energetic (>25 keV) ion events: Interball-1/DOK-2 observations
Abstract The rise time of ions of various energies to reach the “plateau” phase of an event is a crucial parameter in the research of upstream ion events. In this paper, we present observational results on various parameters related with the onset phase of a large number (242) of upstream events. Our study was based on the statistical analysis of high time resolution energetic (> ∼ 25 keV) ion data obtained by the DOK-2 experiment onboard the Interball-1 spacecraft in the years 1996 and 1997. The main results of the study are the following: (1) The average rise times for ∼ 105 keV and ∼ 58 keV ions are 105 > ≊ 9 min and 58 > ≊ 6.6 min , respectively, (2) The average delay between the beginning times of the plateau phase of events at ∼26 keV and ∼105 keV is 26 −T 105 | > ≊ 5.6 min , and (3) The percentage of events displaying forward, inverse and non energy dispersion between the beginning of the plateau phases of ion fluxes (at ∼105 keV and ∼26 keV) was evaluated to be ∼35%, 32% and 33%, respectively; i.e. 68% do not show inverse energy dispersion. These findings are consistent with the leakage model of magnetospheric particles, although appear to pose serious problems to most Fermi type acceleration models as applied at the Earth's bow shock.
Strategies for glass based photonic system integration
There is a clear tendency to integrate more and more opto-electronic and micro-optical components like optical fibers, laser diodes, modulators, isolators, beam-splitting components and micro lenses in also increasingly dense and complex assemblies. The paper will discuss thin glass as a very promising base material for that kind of photonic packaging on interposer and board level including optical interconnection using fibers.