摘要:

A servo‐controlled measuring bridge for resistivity and Hall effect measurements on semiconducting materials with specimen resistances of up to 1013&OHgr; is described.

ISSN:0034-6748    

DOI:10.1063/1.1719697

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

This paper is a report of a study undertaken to ascertain the feasibility of developing identically photoresponsive CdS crystals for x‐ray monitoring applications. Of the crystals studied nearly one half could be matched into pairs with very nearly identical photoresponse to changes in visible and x‐ray (30 kV) irradiation intensity.

ISSN:0034-6748    

DOI:10.1063/1.1719698

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

A liquid helium cryostat which is inexpensive and simple to build is described. Its main features originate from the use of spherical metal floats arranged concentrically to form the body of the vessel. The tailpiece used with the cryostat provides for liquid helium to circulate in the sample holder. A mechanical valve allows the flow of liquid to be interrupted so that temperatures above 4.2°K may be maintained. A typical combination of cryostat and tailpiece has a capacity for 2 liters of liquid helium and will store this charge for nearly 4 days.A liquid nitrogen vacuum system cold trap and a liquid helium transfer tube are also described. The former also features the use of metal floats in its construction. The transfer tube has a degree of flexibility and a very small outer diameter.

ISSN:0034-6748    

DOI:10.1063/1.1719699

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

Methods for reducing linewidths in electron spin resonance spectroscopy by 50–70% using complex magnetic field modulation waveforms are described. Results obtained using a field modulation line sharpener are presented to demonstrate the usefulness of such techniques.

ISSN:0034-6748    

DOI:10.1063/1.1719700

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

The development of a high gain, stable electron multiplier is described. The configuration investigated consists of two rectangular, continuous dynodes forming a plane‐parallel channel. Details of strip preparation, film deposition, and experimental performance values are discussed.

ISSN:0034-6748    

DOI:10.1063/1.1719701

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

A new solution calorimeter is described which combines the thermometric titration techniques with the precision and accuracy of conventional solution calorimetry. The calorimeter through use of a unique design has a low heat leakage,k= 1.1×10−3min−1, and a short equilibration period, 1–3 sec. Measurements of quantities of heat as small as 4 calories with an accuracy of 0.1% are possible. The heat of ionization of water at zero ionic strength has been determined to be 13.34±0.02 kcal/mole which is in excellent agreement with the value of 13.34±0.01 kcal/mole determined by conventional solution calorimetry. The large amount of information obtained from a single run makes this type of calorimeter a valuable addition to the field of solution calorimetry.

ISSN:0034-6748    

DOI:10.1063/1.1719702

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

The effect of pile‐up distortion in the pulse height spectrum of a detector has been determined in the form of an integral representation. A number of important special cases, which arise in experimental applications, are treated. The integral representations for these cases have been evaluted in regions of experimental interest. Comparisons are given between the present numerical results and other estimates of pile‐up distortion.

ISSN:0034-6748    

DOI:10.1063/1.1719703

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

A model study is described in which a rotating capacitor is coupled to a large re‐entrant cavity. The size and capacitive loading (∼500 pF) are such as to make modulation by ferrites or broadband amplifiers difficult and expensive. A nominal frequency range of 3 to 1 is achieved with a single‐plate six‐bladed rotor. On a possible fullscale cavity with a range of approximately 9 to 3 Mc, the data are scaled to a voltage of 5 kV peak for rf power requirements of 1 to 4.4 kW.

ISSN:0034-6748    

DOI:10.1063/1.1719704

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

A test has been made of the accuracy with which an ice‐water system establishes the equilibrium temperature. A device consisting of a bulb containing ice and water with provision for volumetric measurement is used as a thermometer. This was placed in the re‐entrant well of a chamber similar to those used to establish the triple point. The temperature established by the well chamber was varied by varying the pressure of the water in it. It was found that when the temperature was made to differ from the equilibrium temperature of the thermometer by as little as 3×10−6°C, growth or melting occurred in the thermometer.

ISSN:0034-6748    

DOI:10.1063/1.1719705

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

The design of a small vacuum cryostat and furnace for a Mo¨ssbauer spectrometer is described. A regulating system for a 0.1°C temperature stability for periods of several days is given.

ISSN:0034-6748    

DOI:10.1063/1.1719706

出版商:AIP    

年代:1965

数据来源: AIP