Ion laser plasmas

The typical noble gas ion laser plasma consists of a high-current-density glow discharge in a noble gas, in the presence of a magnetic field. Typical CW plasma conditions are current densities of 100 to 2000 A/cm^2, tube diameters of 1 to 10 mm, filling pressures of 0.1 to 1.0 torr, and an axial magnetic field of the order of 1000 G. Under these conditions the typical fractional ionization is about 2 percent and the electron temperature between 2 and 4 eV. Pulsed ion lasers typically use higher current densities and lower operating pressures. This paper discusses the properties of ion laser plasmas, in terms of both their external discharge parameters and their internal ion and excited state densities. The effect these properties have on laser operation is explained. Many interesting plasma effects, which are important in ion lasers, are given attention. Among these are discharge nonuniformity near tube constrictions, extremely high ion radial drift velocities, wall losses intermediate between ambipolar diffusion and free fall, gas pumping effects, and radiation trapping. The current status of ion laser technology is briefly reviewed

Optimal design of switched reluctance motors

The fundamental theory of the switched reluctance motor is presented with a number of new equations. It is used to show how the practical development of a design calculation should proceed, and this leads to a discussion of physical characteristics required to achieve satisfactory performance and to reduce acoustic noise. The paper makes a few generic observations on the characteristics of successful products that use switched reluctance motors. It is written at a basic engineering level and makes no attempt to apply sophisticated optimization theory

Index to NASA Tech Briefs, January - June 1966

Index to NASA technological innovations for January-June 196

Design of the Annular Suspension and Pointing System (ASPS) (including design addendum)

The Annular Suspension and Pointing System is an experiment pointing mount designed for extremely precise 3 axis orientation of shuttle experiments. It utilizes actively controlled magnetic bearing to provide noncontacting vernier pointing and translational isolation of the experiment. The design of the system is presented and analyzed

Magnetoplasmadynamic thrustor research Final report

Radiation-cooled and water-cooled magnetoplasmadynamic thrustors tested in 10 to kW power range with 1000 to 5000 sec specific impuls

Ion sources for high-power hadron accelerators

Ion sources are a critical component of all particle accelerators. They create the initial beam that is accelerated by the rest of the machine. This paper will introduce the many methods of creating a beam for high-power hadron accelerators. A brief introduction to some of the relevant concepts of plasma physics and beam formation is given. The different types of ion source used in accelerators today are examined. Positive ion sources for producing H+ ions and multiply charged heavy ions are covered. The physical principles involved with negative ion production are outlined and different types of negative ion sources are described. Cutting edge ion source technology and the techniques used to develop sources for the next generation of accelerators are discussed.Comment: Presented at the CERN Accelerator School CAS 2011: High Power Hadron Machines, Bilbao, 24 May - 2 June 201