摘要:

A radial sector FFAG accelerator has been constructed and successfully operated. In this 8‐sector accelerator electrons are betatron accelerated from 25 to 400 kev using both continuous and pulsed injection. The number of radial betatron oscillations per revolution may be varied from 2.3 to 3 and the number of vertical oscillations per revolution from 1 to 3. Calculations of these oscillation frequencies using various approximations are described and discussed. These frequencies have been measured statically with the unaccelerated beam and dynamically using an rf perturbing voltage on the accelerated beam. Results of these calculations and experiments are in satisfactory agreement. Effects of misalignments have been measured and are in close agreement with calculations presented. A survey has been made over a large area of the betatron oscillation stability region. The effects of the many resonances observed are in good qualitative agreement with theory.

ISSN:0034-6748    

DOI:10.1063/1.1715895

出版商:AIP    

年代:1957

数据来源: AIP

摘要:

A spectrometer for analyzing photons of energies extending up to several Bev has been constructed and used successfully. This instrument essentially consists of a cylinder of glass, 12‐in. diam and 14‐in. long containing 52% of PbO, viewed by four 5‐in. diam photomultipliers. High‐energy photons incident along the spectrometer axis produce electron showers in the transparent high‐Z glass. The total Cˇerenkov radiation emitted by these electrons and detected by the phototubes is nearly proportional to the energy of the incident photon, from 50 Mev to at least 1.4 Bev. The spectrometer has been calibrated over this range of photon energies by the pulses produced by electrons of the same energies. Above 200 Mev the measured energy resolution of the spectrometer is 30% and is approximately independent of energy. For elimination of incident charged particles during the analysis of &ggr; rays the spectrometer is operated in coincidence with a preceding photon‐identifying counter system.

ISSN:0034-6748    

DOI:10.1063/1.1715896

出版商:AIP    

年代:1957

数据来源: AIP

摘要:

The effect of finite channel width in distorting intensities of monoenergetic lines in a scintillation spectrometer is considered. It is found that peak area divided by channel width gives the rate of monoenergetic absorptions in the crystal. A correction to intensities proportional to the square root of the pulse height is not applicable.

ISSN:0034-6748    

DOI:10.1063/1.1715897

出版商:AIP    

年代:1957

数据来源: AIP

摘要:

The behavior of wavelength shifters in liquid scintillators is discussed. The properties necessary in order that a fluorescent compound act as a wavelength shifter are considered in detail and a qualitative criterion for efficient wavelength shifting is presented. Several double solute solutions have been tested; accordingly it was found that the criterion is useful.

ISSN:0034-6748    

DOI:10.1063/1.1715898

出版商:AIP    

年代:1957

数据来源: AIP

摘要:

The use of the scintillation technique for radiocarbon dating has until now been retarded by the difficulties encountered in the chemical procedure. This paper shows it to be feasible to use the carbon dioxide obtained by combustion of the sample, without any further chemical conversion, as a diluent in a scintillation solution. Up to 80% by weight and possibly more liquid carbon dioxide can be dissolved in toluene+5 g/l diphenyloxazole (PPO). However, the presence of CO2in the scintillator interferes somewhat with the light emission in such a way that the decrease in pulse height, as compared with pure toluene+5 g/l PPO, is 50% for 20% by weight dissolved CO2. This limits the percentage of CO2that can be used effectively to about 30%.The counting rate due to modern carbon is 9.1 c/min, and the background is 15.5 c/min. Measurements indicate however that both these figures can be improved considerably, so as to make this technique at least comparable with the gas‐counting technique.

ISSN:0034-6748    

DOI:10.1063/1.1715899

出版商:AIP    

年代:1957

数据来源: AIP

摘要:

A process is described for the manufacture of disks of plastic scintillators weighing over 100 kg and composed of polystyrene (∼99%),p‐terphenyl (∼1%), and POPOP (∼0.03%). The design and performance of two large plastic scintillation detectors for cosmic rays are discussed.

ISSN:0034-6748    

DOI:10.1063/1.1715900

出版商:AIP    

年代:1957

数据来源: AIP

摘要:

An instrument that will simulate the anomalous gravity effects of a subsurface body, having a density differing from that of its surroundings, is described. The device makes use of the similarity between the gravity equation and Lambert's cosine &thgr; law, and enables the geophysicist to synthesize the anomaly producing body in a time much shorter than that required for conventional computational methods. The accuracy that can be expected is ±5% of the maximum anomaly within limitations noted in the paper.

ISSN:0034-6748    

DOI:10.1063/1.1715901

出版商:AIP    

年代:1957

数据来源: AIP

摘要:

Coaxial and rectangular wave‐guide oscillators are described which yield frequencies of 4 to 6 kilomega‐cycles per second. A metal cap fitted around the anode end of the tube confines the anode grid cavity entirely inside the tube. Studies of efficiency indicate that the upper limit in frequency of the GL‐6299 tube is imposed by the circuit inside the tube and not by the electronics of the tube.

ISSN:0034-6748    

DOI:10.1063/1.1715902

出版商:AIP    

年代:1957

数据来源: AIP

摘要:

A time‐to‐pulse‐height converter is described which uses an rf vernier technique to facilitate the timing of an event with respect to the phase of a high‐frequency clock. The event starts an oscillator whose frequency differs only slightly from that of the reference clock. The phase of the low‐frequency beat note is used as an index of the phase of the clock at the time the event occurred.The system is particularly adaptable to studying fast neutron velocity distributions when the neutron pulses are produced at high repetition rates. It uses a minimum of fast circuit elements, is useful over almost the entire period between pulses at 20 Mc and higher, and gives unambiguous results. The performance with random pulses and with neutron groups has been studied with a 100‐channel pulse‐height analyzer.

ISSN:0034-6748    

DOI:10.1063/1.1715903

出版商:AIP    

年代:1957

数据来源: AIP

摘要:

An air circulating pump that works on the principle of acoustic wind is described. The pump will move up to 700 l/min of air when powered at 60 cps by a 4‐in. loudspeaker. The speaker diaphragm is the only moving part and could be protected by inert material when it is desired to seal in and circulate corrosive gases. Alternating current pickup from the speaker is so small as to be negligible in most instances.

ISSN:0034-6748    

DOI:10.1063/1.1715904

出版商:AIP    

年代:1957

数据来源: AIP