In a specially designed radiation force balance (RFB), low-frequency pulse modulation of the incident ultrasound allows high-accuracy measurement of time-averaged spatially-integrated ultrasound power radiated into a reflectionless water load. Errors characteristic of force sensors are precluded by operating the RFB as a force comparator, without directly measuring force. Equipped with purpose-...

We consider the effects of an outflow on radiation escaping from the infalling envelope around a massive protostar. Using numerical radiative transfer calculations, we show that outflows with properties comparable to those observed around massive stars lead to significant anisotropy in the stellar radiation field, which greatly reduces the radiation pressure experienced by gas in the infalling ...

We perform numerical simulations of magneto-rotational instability in a local patch of accretion disk in which radiation pressure exceeds gas pressure. Such conditions may occur in the central regions of disks surrounding compact objects in active galactic nuclei and Galactic X-ray sources. We assume axisymmetry, and neglect vertical stratification. The growth rates of the instability on initia...

An intensity-modulated HeNe-laser beam was utilized to optically actuate the mechanical resonance of a macroscopic torsional silicon oscillator (f 0 = 67 700 Hz, Q = 42 100 at p = 1 mbar and T = 300 K). Both radiation pressure and photothermal effects may cause optical actuation of a mechanical device. Both excitation effects were studied. In actuation through radiation pressure, the actuating ...

Radiatively-driven flow in a luminous disk is examined in the subrelativistic regime of (v/c), taking account of radiation transfer. The flow is assumed to be vertical, and the gravity and gas pressure are ignored. When internal heating is dropped, for a given optical depth and radiation pressure at the flow base (disk “inside”), where the flow speed is zero, the flow is analytically solved und...

Radiation trapping and transport are important to the power balance of low pressure non-equilibrium plasma lighting sources. This is particularly the case for radio frequency inductively coupled lamps having complex geometries and where control of radiation trapping is an important design consideration. To investigate these issues, a Monte Carlo radiation transport simulation was developed and ...

We developed a technique of picking up the liquid surface in a noncontact manner by a cw-laser radiation. The momentum change of light at the laser transmission through the air-liquid interface appears as the radiation pressure, which deforms the liquid surface into the shape determined by the balance between the Laplace force of the curved surface and the radiation pressure. The displacement o...

This article suggests five classes of effort that scientists can undertake to destroy the linear no-threshold hypothesis as the basis of radiation regulation in the United States. These are (1) pressure on regulators such as the Nuclear Regulatory Commission, (2) presidential messages, (3) Congressional pressure, (4) educate physicians about low-dose radiation, and (5) work with journalists and...

The major objective of this study is to develop an integrated orbit, attitude, and structural control system architecture for very large Space Solar Power Satellites (SSPS) in geosynchronous orbit. This study focuses on the 1.2-GW “Abacus” SSPS concept characterized by a 3.2 × 3.2 km solar-array platform, a 500-m diameter microwave beam transmitting antenna, and a 500 × 700 m earth-tracking ref...