摘要:

The response of plastic scintillators to the flux of particles occurring in cosmic ray air showers has been measured at various distances from the center of showers of various sizes. The number of ``scintillator particles''Sobtained by dividing the observed pulse height by the mode of the pulse‐height distribution due to single fast muons has been compared with the number of incident ionizing particlesGseen by Wilson cloud chambers and Geiger counters. The ratioS/Gis always greater than unity. It increases with increasing number of charged particles per square meter, being 1.1 for 100 scintillator particles per m2and 4.0 for 10 000 scintillator particles per m2. It varies with radial distance from the shower center and with shower size, being 1.2 on average at 30 m from the center of showers of ∼105particles and greater than 4 near the center of large showers. The increase inS/Gis partly due to cascading of the electromagnetic component within the plastic scintillator but mostly to nuclear interactions produced in the scintillator by strongly interacting particles.

ISSN:0034-6748    

DOI:10.1063/1.1719639

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

An instrument has been designed to measure the temperature of a sample suspended in a thermobalance without interfering with the balance operation. Continuous and simultaneous temperature and weight records therefore can be obtained. The instrument uses the principle of a magnetic amplifier to sense a current caused by the potential generated by a thermocouple in the sample. A dc potential linear with temperature is recorded. Precision has been demonstrated to be better than 2°C up to 700°C. No measurable effect of the temperature transducer on weight recorded by the analytical balance was detected. Buoyancy and convection effects on weight are discussed.

ISSN:0034-6748    

DOI:10.1063/1.1719640

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

A new design for the measurement of the electrical conductivity of the atmosphere under severe conditions is described. The main features include novel means for minimizing the difficulties of maintaining a high insulation resistance not only for the central system, but for the polarizing batteries. The insulators are sapphire rods mounted in a side arm where the relative humidity is maintained at very low values by an external and isolated heater. The polarizing batteries are mounted inside a Faraday cage carried by the same insulators. Provisions are made to define accurately the electrical capacity of that part of the system exposed to the ambient ions so that this critical factor can be reliably measured. The apparatus is designed to minimize the loss of ions to the walls of the induction system by eddy diffusion.

ISSN:0034-6748    

DOI:10.1063/1.1719641

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

A current‐to‐frequency converter for gamma MeV measurements is described. In this application a photo‐multiplier tube is used as the current source. Currents as low as 10−9A have been measured with a long term stability of 0.09 %/8h period. Extremely low leakage is achieved by the use of a field effect transistor at the input. The current to be measured is integrated and digitized. The output pulses are then fed to a frequency counter for digital readout.

ISSN:0034-6748    

DOI:10.1063/1.1719642

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

Thermoelectric instabilities of noble metal thermocouples and individual thermoelements (platinum, rhodium, iridium, platinum‐rhodium, and iridium‐rhodium alloys) have been studied in vacuum in the temperature range 800 to 1600°C. These studies are an extension of previous work performed in oxidizing and neutral atmospheres. As in that work, the principal source of instability was found to be contamination of the thermoelements by impurities from ceramic protection tubes. Thermocouple errors associated with this contamination are reported and compared with the previous data.

ISSN:0034-6748    

DOI:10.1063/1.1719643

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

A 90° bendn=0 magnetic spectrometer has been constructed which uses curved field boundaries to achieve second order correction of the focal properties and to make the image plane normal to the emerging particles. The spectrometer has a 112 cm radius of curvature and a maximum momentum capability of 725 MeV/c. The window frame yoke, with sloping edge profiles to minimize edge saturation, enables the focal properties to remain invariant up to 21 kG. The solid angle acceptance is 8×10−3sr with 0.1% resolution and the maximum momentum acceptance is ±5%.

ISSN:0034-6748    

DOI:10.1063/1.1719644

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

A laboratory instrument is described which is capable of precise measurements of refraction, transmission, polarization, and reflection from 1700 to 11 000 Å. The instrument consists of eight modular units that can be bolted together in various serial arrangements as required for the particular test. A goniometer specimen chamber and specimen carriage of unusual design are described. The specimen chamber utilizes a transit dial and is readable to 20″.

ISSN:0034-6748    

DOI:10.1063/1.1719645

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

Special valves have been constructed to meet the constant volume requirements of a gas thermometry program. With a total volume inside the valve block less than 20 mm3, and that which is a part of the gas thermometer about 3 mm3, no change in excess of 0.005 mm3is expected. This is achieved by extending the valve stem past the seat through a seal on the opposite side, so that the volume of stem pulled into the gas chamber is equal to the volume withdrawn when the valve is opened.

ISSN:0034-6748    

DOI:10.1063/1.1719646

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

A cryostat with a load capacity of 10 000 lb has been designed for use with standard tensile testing equipment in the temperature range 4 to 300°K. Specimens up to 12.7 cm long can be mounted easily on the grip rods through an opening in the front of the test chamber. The cryostat is used in conjunction with a 10 000 lb Instron tension testing machine containing a stress‐strain recorder and strain pacer.

ISSN:0034-6748    

DOI:10.1063/1.1719647

出版商:AIP    

年代:1965

数据来源: AIP

摘要:

The power output of an RF generator coupled to a graphite cylinder can be conveniently measured by determining the equilibrium temperature of the cylinder with an optical pyrometer and using the blackbody formula to obtain the power radiated by the cylinder. This power was found to agree closely with the generator output measured with a conventional water‐cooled calorimeter. Graphite, with a resistivity of about 10−3&OHgr; cm, easy machinability, and good blackbody characteristics, is an excellent dummy load for studying the output of RF generators to such relatively high resistivity loads as plasmas and semiconductors. The pyrometer method has also been used to determine the coupling efficiency of a generator as a function of the ratio of load diameter to coil diameter. Efficiencies of 27, 41, 59, and 63% were found for ratios of 0.46, 0.61, 0.77, and 0.92, respectively.

ISSN:0034-6748    

DOI:10.1063/1.1719648

出版商:AIP    

年代:1965

数据来源: AIP