1. Place animal in induction chamber and anesthetize the mouse and ensure sedation. 2. Once the animal is sedated, move it to a nose cone for hair removal using cream. Only apply cream to the area of the chest that will be utilized for imaging. Once the hair is removed, wipe area with wet gauze to ensure all hair is removed. 3. Move the animal to the imaging platform and tape its paws to the ECG lead plates and insert rectal probe. Body temperature should be maintained at 36-37°C. During imaging, reduce anesthesia to maintain proper heart rate. If the animal shows signs of being awake, use a higher concentration of anesthetic.

人唾液天疱疮抗原的纯化

Scientific and technical progress made in the utilization of electron beams injected from large sounding rockets for the investigation of magnetospheric structure and dynamics and plasma physics is reviewed. Consideration is given to the problem of vehicle neutralization during the generation of electron beams in the ionosphere and the stability and electromagnetic wave emissions of electron beams propagating in space. Optical effects observed during the two Hess artificial aurora experiments, the Minnesota Echo IV and V experiments, the Zarnitsa-1 artificial aurora experiment and the Precede-Excede experiments are discussed, together with atmospheric scattering effects observed during Echo I, II and III, and results of the three experimental programs which have detected and analyzed beams after passage through the distant magnetosphere (the second Hess experiment, ARAKS and the Electron Echo experiments) are presented. Finally, plans for future research are outlined, and a chronology and complete bibliography of the programs conducted to date are included.

The application of artificial electron beams to magnetospheric research

Further laboratory measurements of the beam-plasma discharge (BPD) produced when an energetic electron beam traverses an initially neutral gas are presented. The experimental data indicate that the critical beam current Ic at energy V, magnetic field B, and system length L required for ignition obeys the empirical relationship Ic ∝ V3/2/B0.7 PL at pressures P < 2 × 10−5 torr. This relationship appears to primarily describe the accumulation of ambient plasma density, collisionally produced by the beam itself, to a critical value where ωpe² ≈ ωce² at which ignition occurs. Additional measurements of the narrow-band cyclotron-related waves (fce < f < 1.4fce) observed at beam currents below BPD threshold do not clearly establish whether this instability is a necessary precursor to the BPD. The relevance of these experiments to past and planned electron beam experiments in space is briefly discussed.

Further laboratory measurements of the beam-plasma discharge. [for aerospace technology application]

Large-amplitude (10 to 100 μV m−1 Hz−½) natural radio emissions in a wide frequency range (100 kHz up to 2 MHz) are frequently observed on board the AUREOL/ARCAD 3 satellite at high latitude and at altitudes between 400 and 2000 km. The simultaneous measurement of the local cold plasma density allows the identification of cutoff and resonance frequencies. Three different kinds of wave are observed: (1) electrostatic emissions near the local value of the plasma frequency (fp), (2) electromagnetic whistler mode emissions, sometimes associated with type (1) emissions, and (3) electromagnetic Z mode emissions, also associated with type 1 emissions, but occurring more rarely than the whistler mode emissions and then only when fp is greater than the electron cyclotron frequency (fce). These emissions are always associated with high levels of ELF electrostatic turbulence and a high flux of low-energy precipitating electrons, extending in energy down to the lower limit of the detectors (∼100 eV). The statistical distribution of the emissions in geomagnetic coordinates shows an occurrence greater than 80% in the polar cusp region and between 25% and 60% in the nightside auroral zone. A generation mechanism for such emissions is proposed, based on the calculation of the growth rate of the kinetic Cherenkov instability, associated with a beamlike suprathermal tail in the parallel distribution of the bulk electron population. In particular, suprathermal, downward electron beams of about 100–200 eV energy, with a thermal spread of the same order, are found to be responsible for the generation of whistler mode and Z mode HF emissions in a source region extending down to 1000 km of altitude. It is suggested that such intense radio emissions should be considered as one of the energy dissipation processes resulting from magnetosphere-ionosphere coupling, through interdependent electrodynamic mechanisms such as current systems, parallel anomalous resistivity, plasma turbulence, energy diffusion, and heating.

Electrostatic plasma waves and HF auroral hiss generated at low altitude

The first active beam-plasma experiments utilizing the space shuttle were carried out in March 1982 as part of the NASA Office of Space Science mission on the third space shuttle flight. A fast pulse electron generator emitted a 1-keV, 100-mA electron beam in either a continuous (dc) mode or an on/off modulated mode in the ELF to HF frequency range. Stimulated electrostatic and electromagnetic waves and associated plasma effects were measured with the plasma diagnostics package as it was maneuvered through and near the beam by the remote manipulator system. For the dc beam the wave spectrum was electrostatic, was peaked in the 300- to 500-Hz range with a spectral density of 4 × 10−3 V2 m−2 Hz−1, and was unpolarized. Above the nominal lower hybrid resonance frequency the intensity decreased but was polarized. Strong emissions near the electron gyrofrequency and the plasma frequency were occasionally detected. The background spectrum was similar to the dc case for VLF and ELF modulations, but the emissions at the modulation frequency were more electromagnetic and more intense with field strengths of up to 1 Vm−1.

Wave emissions from dc and modulated electron beams on STS 3

POLAR 5—an electron accelerator experiment within an aurora. 2. Scattering of an artificially produced electron beam in the atmosphere

Polar 5—an electron accelerator experiment within an aurora. 1. Instrumentation and geophysical conditions

Polar 5—an electron accelerator experiment within an aurora. 4. Measurements of the 391.4 nm light produced by an artificial electron beam in the upper atmosphere

B. Grandal

Papers

POLAR 5—an electron accelerator experiment within an aurora. 2. Scattering of an artificially produced electron beam in the atmosphere

Polar 5—an electron accelerator experiment within an aurora. 1. Instrumentation and geophysical conditions

Polar 5—an electron accelerator experiment within an aurora. 4. Measurements of the 391.4 nm light produced by an artificial electron beam in the upper atmosphere

Observations of waves artificially stimulated by an electron beam inside a region with auroral precipitation