摘要:

The soft particle spectrometer uses electrostatic deflection for simultaneous measurement of the differential energy spectra of electrons and protons. The energy range is from 10 eV to 10 keV per unit charge with ±40% energy spread. Twelve stage BeCu electron multipliers are used as detectors in the counting mode over a five decade dynamic range. A swept mode of energy selection provides a spectrum in 0.5 sec for high fluxes, while a stepped mode suitable for lower fluxes takes 40 sec. A typical electron spectrogram for a transpolar pass is included as an example of the data reduction procedure used.

ISSN:0034-6748    

DOI:10.1063/1.1684291

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A versatile low energy electron gun suitable for electron‐atom scattering experiments has been designed utilizing photoetched grids and precision ceramic spacers which stack onto ceramic rods. Diagnostic techniques are described which determine the absolute electron energy to within ±0.1 eV. Electron guns which operate over the energy range 0.1–25 eV with currents up to 10 mA and energy spreads as low as 0.2 eV have been built using the design presented here.

ISSN:0034-6748    

DOI:10.1063/1.1684292

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

An electro‐optical system for observing high pressure, low temperature phase equilibria phenomena has been tested at 25 MN·m−2and liquid nitrogen temperatures. The system consists of a uv source exciting an intracell fluorescent pigment which illuminates the cell interior. The cell is observed by a closed circuit television camera and monitor, and a permanent record is made with a video tape recorder.

ISSN:0034-6748    

DOI:10.1063/1.1684293

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A description is given of a new parallel plate electrostatic spectrograph. A parallel plate electrostatic analyzer has been discussed previously, in which particles issuing from a point source on the earthed plate are deflected by the electric field and brought to a focus on that plate, provided the angle of entrance to the field is 45°. This is a simple example of the more general focusing properties of a parallel plate analyzer. From consideration of these properties, it has been found possible to select a given angle of entry into the field for which second order focusing can be attained giving rise to an angular aberration term proportional to (&Dgr;&thgr;)3. Uslng an acceptance of ±6° a resolving power of 200 is predicted and has been obtained with a prototype.

ISSN:0034-6748    

DOI:10.1063/1.1684294

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

An internal heater arrangement for hydrostatic pressure experiments (Teflon cell technique) at elevated temperatures is described. With fluid pressure media such as silicone oil, Nujol, etc., temperatures in the range of 350°C at pressures up to 30 kilobars have been achieved. Since direct current is employed for heating, pickup problems associated with very sensitive electronic detection techniques are eliminated.

ISSN:0034-6748    

DOI:10.1063/1.1684295

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

An image orthicon detection and recording system has been adapted for making spectroscopic measurements in shock tube emission studies. The system provides greater sensitivity than film and permits electronic control of both the timing and duration of the exposure. The linear response with light intensity and immediate recording of output on an oscilloscope trace makes the system a convenient diagnostic tool. A description of the system as well as quantitative spectroscopic data obtained with it is presented.

ISSN:0034-6748    

DOI:10.1063/1.1684296

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A data acquisition system is described that obtains reflected intensity measurements in digital form directly on punched cards. The cards can then be fed directly to a computer to calculate reflectances, thus eliminating the time consuming process of reducing strip chart recordings to reflectances. In addition, the precision with which the reflectances can be calculated is improved, which is important if they are to be used to calculate optical constants.

ISSN:0034-6748    

DOI:10.1063/1.1684297

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A new gaseous discharge source has been developed for use in measurement of atomic and molecular electronic state lifetimes where the transitions occur in the range 1000–12 000 Å. The source is a coaxial aluminum cold cathode‐anode device utilizing fast pulse circuits, magnetic field breakdown enhancement, and a flowing gas supply. Excitation of gaseous species is achieved by electron collisions in the discharge. The cold cathode device can be used with any gaseous species since its source of electrons is not a heated oxide‐coated cathode. Excitation fall times of 2 nsec are obtained.

ISSN:0034-6748    

DOI:10.1063/1.1684298

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

Coherent signal detection techniques are applied to conventional ultrasonic pulse‐echo measuring apparatus to achieve a 20–25 dB improvement in the minimum useful signal. Logic circuitry is described which generates all the reference and trigger waveforms required by the sampling oscilloscope, lock‐in amplifier, and other equipment. No other pulse generators are required. Amplitude adjustment of the pulsed rf comparator is determined to be equal that of the echo by a null indication of the lock‐in voltmeter.

ISSN:0034-6748    

DOI:10.1063/1.1684299

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A simple, easily maintained air spark gap of ∼7 nH inductance was developed to switch 0.24 C stored charge at 20 kV in an LC circuit having a period of ∼4 &mgr;sec. A similar 3 nH spark gap with an auxiliary triggering circuit was used to clamp the magnetic flux within the load near the voltage minimum. Voltages up to 30 kV and currents to 5×105A have been handled. Acoustic noise was minimized by completely enclosing the arc, and forced air venting removed corrosive gases and helped control the temperature to improve reproducibility.

ISSN:0034-6748    

DOI:10.1063/1.1684300

出版商:AIP    

年代:1970

数据来源: AIP