摘要:

A wall stabilized arc constrained to operate within a transparent tube is described. The device produces a plasma column of true cylindrical symmetry, justifying a one dimensional analysis of energy transfer within the column. Axial temperatures in excess of 12 000°K have been achieved in argon.

ISSN:0034-6748    

DOI:10.1063/1.1720172

出版商:AIP    

年代:1966

数据来源: AIP

摘要:

A sample changing device for a mass spectrometer is described. Five filaments are mounted on a wheel which is adapted to be rotated by suitable drive mechanism through the vacuum wall. Reliable wiping electrical contact is made to the filament lugs by means of stationary blades, spring loaded with tungsten wire helices.

ISSN:0034-6748    

DOI:10.1063/1.1720173

出版商:AIP    

年代:1966

数据来源: AIP

摘要:

The photoelectric yield of a metal has been shown to increase with increasing angle of incidence of the radiation. The reflected radiation is reused to cause further photoemission until the incident radiation is entirely absorbed. Using an eighteen sided aluminum polygon to totally absorb the radiation, the photoelectric yield of the polygon compared to that of a single plate used at normal incidence was increased by a factor of 5.5 at 209 Å and by 40% at 1216 Å. The yield of the polygon cathode was in excess of 16% between 200 and 1000 Å with a maximum yield of 28% at 350 Å.

ISSN:0034-6748    

DOI:10.1063/1.1720174

出版商:AIP    

年代:1966

数据来源: AIP

摘要:

Following a discussion of flashtube impedance and its dependence upon discharge current, the relation between current magnitude, initial charge voltage, circuit constants, and lamp dimensions is derived for lamps operating in pulse forming networks of cascadedLCpisections. The resulting equation,I=0.27(d/l)23(C/L)13V43, has been experimentally verified by data from flashtubes having arc lengths ranging between 7.6 and 91.5 cm. When, as is often the case, a flashtube is operated in series with a single inductor, the current pulse is not rectangular and the assumption of constant discharge resistance used in the multisection line study is invalid. A more precise analysis has been carried out with the aid of a digital computer in which the differential equation for a series RLC circuit is solved with the nonlinear conditionR=Rw+R(i). Inclusion of wiring resistanceRwpermits further extension of the solution's applicability and the results are found to agree well with experiment.

ISSN:0034-6748    

DOI:10.1063/1.1720175

出版商:AIP    

年代:1966

数据来源: AIP

摘要:

Properties such as reflectance, deterioration in water, and deposition of activities are investigated for several types of optical reflectors. Reflectance values for both visible and ultraviolet light are included and the deterioration tests extend up to water temperatures of 150°C. The influence of reflector properties on detector efficiency is also studied.

ISSN:0034-6748    

DOI:10.1063/1.1720176

出版商:AIP    

年代:1966

数据来源: AIP

摘要:

The effect of the size of the small aperture which isolates the central portion of the interference fringe system in the photoelectric scanning Fabry‐Perot interferometer has been investigated. The phase shift due to size of aperture is given accurately by &Dgr;=K&thgr;2/2, whereKis half the phase difference and &thgr; the angular radius of the aperture, only if the diameter of the aperture is not greater than about one‐eighth of the diameter of the first interference ring. This phase shift is equivalent to a length correction with the Fabry‐Perot interferometer of &thgr;2/4 per unit length. This simple relation cannot be used with larger apertures, and visibility considerations make the use of such apertures quite undesirable.

ISSN:0034-6748    

DOI:10.1063/1.1720177

出版商:AIP    

年代:1966

数据来源: AIP

摘要:

An apparatus is described which can make mechanical property measurements on single filaments at temperatures to 2500°C. It is a constant rate‐of‐strain machine which uses linear variable differential transformers (LVDT's) to measure filament tension and elongation. A split furnace, using graphite heating elements, completely surrounds the filament, which is cemented to graphite supporting rods with a carbonizable cement.

ISSN:0034-6748    

DOI:10.1063/1.1720178

出版商:AIP    

年代:1966

数据来源: AIP

摘要:

A more efficient method for the delivery of protons onto Bevatron targets has been devised. This method involves amplitude modulation of the rf accelerating voltage by a closed loop system that regulates the rate of loss of circulating beam, as observed on a pickup electrode. The efficiency and reliability of this new method are considerably greater than those of previous methods, and the flexibility of proton delivery control has been enhanced.

ISSN:0034-6748    

DOI:10.1063/1.1720179

出版商:AIP    

年代:1966

数据来源: AIP

摘要:

A versatile sampling technique is described which permits a more definitive study of ion extraction and plasma sheath formation in discharge plasmas. The ionic species from the plasma are sampled into a quadrupole mass spectrometer through a metal leak arrangement which itself acts as a probe. This behavior is substantiated by sampling probe characteristics, and charge density and electron temperature determinations for a flowing microwave discharge plasma in nitrogen at low pressure.

ISSN:0034-6748    

DOI:10.1063/1.1720180

出版商:AIP    

年代:1966

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1720181

出版商:AIP    

年代:1966

数据来源: AIP