摘要:

A very simple method has been developed for the control and measurement of an ion source in the top terminal of a high pressure insulated Van de Graaff generator. The sending and receiving of information from the outside of the tank to the high voltage (h.v.) electrode is achieved by means of light signals.

ISSN:0034-6748    

DOI:10.1063/1.1715649

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

Measurements are reported of the use of luminescent materials as a light shifter for Cˇerenkov radiation, with the object of increasing the pulse height from Cˇerenkov light observed by a photomultiplier tube. By this process the directional properties of the Cˇerenkov light are essentially lost.

ISSN:0034-6748    

DOI:10.1063/1.1715650

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

Mirrors suitable for determining coherent cross sections by the neutron reflection technique are prepared by evaporating a sample on a flat electrochemically polished vanadium plate. Samples of separated isotopes as small as 20 mg may be used.

ISSN:0034-6748    

DOI:10.1063/1.1715651

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

An adiabatic specific heat calorimeter bridging the interval between liquid helium and liquid hydrogen temperatures is described. The instrument uses a constant volume helium gas thermometer as the working thermometer. The sample is placed directly in the gas thermometer bulb which thus acts as a sample container. The use of the calorimeter is restricted to bulk samples with low surfaces areas.

ISSN:0034-6748    

DOI:10.1063/1.1715652

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

A precision microscope which may be used with all sizes of nuclear plates up to 10×16 in. has been constructed. Its simplicity of construction, and flexibility and ease of use recommend its general design.

ISSN:0034-6748    

DOI:10.1063/1.1715653

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

Since sound propagation is an adiabatic process, a temperature fluctuation accompanies the sound wave in media for which the specific heat ratio is greater than unity. If the equation of state and the sound field are known, this temperature fluctuation may be related to the intensity of the sound wave.A thermometer capable of measuring fast, small‐amplitude temperature variations is described. Its output is calculated for the case of plane, sinusoidal sound waves in an ideal gas. Its use as a microphone and sound intensity meter is then considered.

ISSN:0034-6748    

DOI:10.1063/1.1715654

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

A method has been developed for determining photometrically the ionization of multiplate cloud chamber tracks. A simple, projection type of photometer is used to measure the track opacity, from which the ionization of the track is obtained by comparison with the opacity of a track of known ionization. The ratio of the properly normalized opacities of the two tracks is related to the ratio of their ionizations by a simple power law. The technique has been employed, with geometric residual range determinations, to find particle masses. It also has been used, when the mass is known, to ascertain the residual range in the plate in which a particle stops. By determining both the ionization and the change in ionization occurring in a plate traversal, both the mass and the residual range of particles have been found. Specific applications include a determination of the range of the secondaries fromK&mgr;2andK&pgr;2decays, and a measurement of the mass of a particle which releases more than 1.6 Bev on stopping. The latter is found to have a mass consistent with its being an antiproton.

ISSN:0034-6748    

DOI:10.1063/1.1715655

出版商:AIP    

年代:1956

数据来源: AIP

摘要:

A novel mass spectrometer with which masses of ions are determined in terms of high harmonics of their cyclotron frequencies is described from both experimental and theoretical viewpoints. Half‐width resolution is adjustable electrically over a range of values presently between 10 000 and 25 000 at all mass numbers below 250. By means of a highly precise technique of matching peaks, relative doublet separations in frequency (&Dgr;f/f) exactly equal to those in mass (&Dgr;M/M) are determined with great ease and accuracy on a ratio scaler. Masses have been determined with an accuracy of better than one part in 107, which is comparable with the best yielded by conventional instruments. Measurements should be of particular importance, even if of no greater precision than others, because the very different techniques employed make unlikely the occurrence of unsuspected systematic errors of the same nature as in other work. Sources of systematic error are discussed. It is believed that most of these have been eliminated, though avoidance of the not uncommon errors caused by differences in orbit distributions in doublets involving ions formed by dissociation has so far led to such large reductions of intensity as to restrict greatly the number of such important doublets for which reliable data have been obtainable. The synchrometer is apparently at a disadvantage to some deflection‐type spectrometers in the matter of intensity, to some extent in principle and to a greater extent (to date) in practice. This disadvantage is enhanced by the difficulties of using an electron multiplier for detecting ions in strong magnetic fields. It is believed that the latter difficulties are not insuperable and it seems reasonable to expect that further work on increasing the intensity and improving the focusing of ions from the source will greatly enhance the number of results obtained. The possibilities of using the instrument for analytical purposes are interesting but so far largely unexplored.

ISSN:0034-6748    

DOI:10.1063/1.1715656

出版商:AIP    

年代:1956

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1715658

出版商:AIP    

年代:1956

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1715659

出版商:AIP    

年代:1956

数据来源: AIP