The above process keeps the # of protons and the # of neutrons in the early Universe constant. This is extremely important and will result in a testable prediction later. Remember, a free neutron (one that is not bound in an atomic nucleus) will decay into a proton + electron (+ anti-neutrino) in about 900 seconds. ... During this epoch, the proton-to-neutron ratio is 1.0 . ... The Universe consists of protons, neutrons and electrons plus a photon background and a neutrino background. ...

... The FOC suffers from various types of background, the most important of which are thermal electrons, Cerenkov radiation from high energy particles, geocoronal emission lines, zodiacal light, and light scattered within HST from the bright Earth or Moon. ... From on-orbit measurements using the f /96 camera, the former background has been found to vary with solar zenith distance (ZD); see Sections 6.4, 6.5, and 7.0 of the FOC Instrument Handbook , version 7.0, for more details. ...

Understanding Europa's Radiation Environment and How it Influences Landing Site Characterization G.W. Patterson, L.M. Prockter, C. Paranicas Applied Physics Laboratory Introduction · The surface of Europa is weathered by charged and neutral particles, micrometeroids, and photons. ... Background · Criteria for characterizing potential landing sites [e.g., Figueredo et al., ... 2004) Background · Criteria for characterizing potential landing sites [e.g., Figueredo et al., ... Figueredo et al., ...

... One important issue for the spectral analysis with X-ray detectors is the treatment of background for extended sources. ... To deal with the particle background (more or less constant outside proton flares), one should assign weights to the reference event list and extract images or spectra using the same spectral or spatial (in detector coordinates) selection as the source. The original spatial selection (on the source) is usually applied to sky coordinates (not detector coordinates). ...

BACKGROUND . ... Electron bombarded silicon (EBS) gain makes the CCD interesting for keV electron detection. Ionizing particles absorbed in silicon create electron-hole pairs at the average rate of one per 3.64 eV incident energy. ... The variance in the number of electron-hole pairs created is given by the Fano factor for silicon (.1-.2) times the number of pairs created. When we use a CCD as a detector of ionizing particles, we would like to collect all of the electrons created. ...

... Research . Projects . ... The name of the project APEX is a reduction from words " Active Plasma Experiments " . The core of the project are active experiments with injection of electron and (or) plasma beams from a board of the satellite with simultaneous registration of the phenomena, produced by interaction of injected beam with background plasma. ... Active experiments utilise modulated electron beam accelerator and source of modulated xenon plasma beam on the main spacecraft APEX. ...

... Plasma sheet is the region of closed field lines in the equatorial magnetotail (however, see also plasmoids ). Plasma sheet is typically divided into plasma sheet proper, or central plasma sheet , and plasma sheet boundary layer (PSBL) , the latter being at higher latitudes adjacent to the tail lobes. ... This is evident both in storms time ring current and substorm time plasma sheet (including late growth and the expansion phases; see, e.g., Daglis et al., ... Res., ... J. Geophys. ...

Next: Error Determination Up: *qpspec* - Extraction of Previous: Spectral Extraction of Extended . Charged particles can be removed from the source and background spectra using the master veto (MV) rate. ... For example, if MV rate = 100, the following command will remove the charged particles in the background and source spectra before determining the net spectrum. xs > qpspec vign_corr=yes avg_mvr=100 . ...