摘要:

An apparatus is described which can be used to measure the velocity of Rayleigh waves and direction of energy flow throughout any given plane in a piezoelectric material. Some results are presented for part of theX‐Zplane in lithium niobate. Additionally, with the use of a thin film transducer the measurements can be extended to non‐piezoelectric materials.

ISSN:0034-6748    

DOI:10.1063/1.1684311

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A method for measuring the total number of negative or positive charges liberated in large silver halide single crystals by shallowly absorbed radiation is described. The use of thin samples allows all the photocharges to be displaced the full thickness of the crystal and induce a certain amount of charge on a series capacitor, whose potential is measured with an oscilloscope. Data at room temperature are obtainable by the use of pulse techniques. Details are given of apparatus used for these experiments and earlier photographic experiments. Repetitive, well formed square pulses up to 500 V and 1 msec or 5000 V and 3 &mgr;sec are obtained. Synchronization with light flashes can be controlled to within a fraction of a microsecond.

ISSN:0034-6748    

DOI:10.1063/1.1684312

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

The concept, design, and construction of a directionally sensitive laser velocimeter for unsteady flow measurements are presented. Oscillatory flow measurements are compared with theoretical predictions.

ISSN:0034-6748    

DOI:10.1063/1.1684313

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

In a double reflecting plate calorimeter, the energy from a laser beam is partially absorbed by metal mirrors. The rest is reflected through an exit where it is free to interact with some medium. Characteristics of this calorimeter with a pair of aluminum plate mirrors are (1) wavelength range ∼0.1−∼1 &mgr;, (2) energy input range ∼0.1−∼50 J/cm2(pulsed normal mode) and estimated power ∼100−∼1000 MW/cm2(pulsed Q switched) depending upon energy density, (3) estimated error ±2% over most of the ranges given, (4) 5 sec for the plates to reach a uniform temperature and to make measurements, and 2–4 min required cooling time between inputs, and (5) both absorption and reflection determined from plate calorimetric data. The sensitivity and the wavelength, energy, and power ranges may be increased by using different plate dimensions and materials. Data from an intercomparison between this calorimeter and an NBS liquid cell calorimeter yield agreement of about 0.6% at 0.6943 &mgr;. The light wasppolarized (electric vector parallel to the plane of incidence). The energy of the components of polarization parallel and perpendicular to the plane of incidence of a light beam may be evaluated.

ISSN:0034-6748    

DOI:10.1063/1.1684314

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A CO2laser has been adapted for use in high speed drilling of fine holes in thin rubber sheeting. The drilled sheeting is useful for vacuum handling microminiature semiconductor components. Holes are drilled at the approximate rate of 25/sec, and the total time required for drilling 31 400 holes of 90 &mgr; diameter on 0.25 mm centers is 38 min.

ISSN:0034-6748    

DOI:10.1063/1.1684315

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

The distribution of elastically scattered ions in the image plane of a one‐directional focusing mass spectrometer is calculated. The spectrometer is of the homogeneous magnetic sector type with the exit slit inside the field. It is shown that elastic scattering of beam ions by residual gas molecules results in peak broadening incompatible with the requirement of a high abundance sensitivity. A special two‐sector instrument with reduced scattering contribution is proposed.

ISSN:0034-6748    

DOI:10.1063/1.1684316

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

Nonrepetitive bursts of ions, several microseconds in duration, with intensities less than 105ions per burst were measured by a linear signal from the ninth PM dynode in a Daly‐type secondary emission detector. The signal height was proportional to the number of ions and was calibrated for various ion species to an estimated absolute accuracy of ±15% and relative accuracy of ±5% between identical detectors.

ISSN:0034-6748    

DOI:10.1063/1.1684317

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A cavity for ESR spectrometers for work in millimeter and submillimeter waves is described. The design principles are explained and results for 75 GHz are demonstrated. The experimental Q at room temperature is higher than 6000.

ISSN:0034-6748    

DOI:10.1063/1.1684318

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A reliable, passively mode locked Nd‐glass laser was developed. The design is described, including provision for frequency doubling with a crystal of KDP and selection of pulses with a Pockels cell. A train of three subnanosecond pulses of light was obtained with individual pulse energies between 1 and 2 mJ, at a wavelength of 530 nm.

ISSN:0034-6748    

DOI:10.1063/1.1684319

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A fused quartz bubble window approximately 0.115 mm thick and several centimeters in diameter has been constructed. It has high far infrared transmittance (∼70–90% for 180 &mgr;<&lgr;<3 mm), can pass a beam of large cross section, and can support a vacuum. The window is a bubble blown inward (convex toward low pressure) to be under tension. Its use avoids the temperature dependent transmission characteristics of crystal quartz, a material often used for vacuum envelope windows because of its high far infrared transmittance. Unlike crystal quartz windows, the fused quartz window can be fused to the envelope. Transmission measurements, lens effects, and reflection losses are discussed.

ISSN:0034-6748    

DOI:10.1063/1.1684320

出版商:AIP    

年代:1970

数据来源: AIP