Pub Date : 1989-10-01DOI: 10.1088/0022-3735/22/10/004
D. Hurley, G. Hardy, P. Hawker, A. Kent
A new technique for spatially resolved detection of heat pulses (phonons) at liquid-helium temperatures is described. Unlike existing phonon imaging methods, this system is not affected by the presence of magnetic fields up to at least 7 T. The method utilises a spatially extended cadmium sulphide thin film as a phonon bolometer. Small (<200 mu m) regions of the film are selectively sensitised by a microcomputer-controlled, scanned laser spot and 'reset' after data acquisition using a large ( approximately=50 mA) current pulse. Using data acquisition and analysis software, line scans of the transmitted phonon intensity as a function of propagation direction are obtained. Sample data of the phonon intensity in the (110) plane of silicon are presented.
{"title":"A spatially resolving detector for heat-pulse experiments","authors":"D. Hurley, G. Hardy, P. Hawker, A. Kent","doi":"10.1088/0022-3735/22/10/004","DOIUrl":"https://doi.org/10.1088/0022-3735/22/10/004","url":null,"abstract":"A new technique for spatially resolved detection of heat pulses (phonons) at liquid-helium temperatures is described. Unlike existing phonon imaging methods, this system is not affected by the presence of magnetic fields up to at least 7 T. The method utilises a spatially extended cadmium sulphide thin film as a phonon bolometer. Small (<200 mu m) regions of the film are selectively sensitised by a microcomputer-controlled, scanned laser spot and 'reset' after data acquisition using a large ( approximately=50 mA) current pulse. Using data acquisition and analysis software, line scans of the transmitted phonon intensity as a function of propagation direction are obtained. Sample data of the phonon intensity in the (110) plane of silicon are presented.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"5 3","pages":"824-827"},"PeriodicalIF":0.0,"publicationDate":"1989-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91439447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-10-01DOI: 10.1088/0022-3735/22/10/006
A. F. Borghesani
Digital recursive and non-recursive filtering techniques have both been exploited to build a low-frequency (0.5-50 Hz), low-distortion digital quadrature oscillator. This generator shows an amplitude constant to within 0.3% over the frequency range, and the quadrature phase error is within +or-0.05 degrees .
{"title":"Low-frequency, low-distortion digital quadrature oscillator","authors":"A. F. Borghesani","doi":"10.1088/0022-3735/22/10/006","DOIUrl":"https://doi.org/10.1088/0022-3735/22/10/006","url":null,"abstract":"Digital recursive and non-recursive filtering techniques have both been exploited to build a low-frequency (0.5-50 Hz), low-distortion digital quadrature oscillator. This generator shows an amplitude constant to within 0.3% over the frequency range, and the quadrature phase error is within +or-0.05 degrees .","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"15 1","pages":"833-837"},"PeriodicalIF":0.0,"publicationDate":"1989-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86495405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-10-01DOI: 10.1088/0022-3735/22/10/001
J. Gallego‐Juárez
The author reviews the basic characteristics and progress in transducer properties of the different types of piezoelectric ceramics. The application of these materials in practical ultrasonic transducers is also reported.
{"title":"Piezoelectric ceramics and ultrasonic transducers","authors":"J. Gallego‐Juárez","doi":"10.1088/0022-3735/22/10/001","DOIUrl":"https://doi.org/10.1088/0022-3735/22/10/001","url":null,"abstract":"The author reviews the basic characteristics and progress in transducer properties of the different types of piezoelectric ceramics. The application of these materials in practical ultrasonic transducers is also reported.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"1 1","pages":"804-816"},"PeriodicalIF":0.0,"publicationDate":"1989-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82176772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-10-01DOI: 10.1088/0022-3735/22/10/002
A. Grun, H. Neitzke, H. Paul, C. Rose
A versatile safety device can serve as a personal flotation device, a rain- or splash-water repellent flotation jacket, a flotation vest with full and constant buoyancy, a multitemperature jacket or vest, a breathing raincoat, and a bullet/fragment-proof safety device, and has an inflatable chamber insert and an optional anti-ballistic insert in the collar. To fulfill all these tasks the device with jacket frame, sleeves and collar, all of which incorporate buoyant material with thermal insulation properties, comprises zippers in the sleeves with water protectors, leg-straps, vacant margins in the areas on the construction seams, and anti-ballistic portions attachable to the device.
{"title":"Versatile safety device","authors":"A. Grun, H. Neitzke, H. Paul, C. Rose","doi":"10.1088/0022-3735/22/10/002","DOIUrl":"https://doi.org/10.1088/0022-3735/22/10/002","url":null,"abstract":"A versatile safety device can serve as a personal flotation device, a rain- or splash-water repellent flotation jacket, a flotation vest with full and constant buoyancy, a multitemperature jacket or vest, a breathing raincoat, and a bullet/fragment-proof safety device, and has an inflatable chamber insert and an optional anti-ballistic insert in the collar. To fulfill all these tasks the device with jacket frame, sleeves and collar, all of which incorporate buoyant material with thermal insulation properties, comprises zippers in the sleeves with water protectors, leg-straps, vacant margins in the areas on the construction seams, and anti-ballistic portions attachable to the device.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"11 1","pages":"817-819"},"PeriodicalIF":0.0,"publicationDate":"1989-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81039510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-10-01DOI: 10.1088/0022-3735/22/10/005
E. W. Randall, C. M. Goodall, P. M. Fairlamb, P. Dold, C. O'Connor
A method is described for measuring the sizes of bubbles in two- and three-phase systems. The length and velocity of each bubble is measured by a pair of optical detectors in a brass block surrounding a capillary tube through which bubbles are drawn. This data is stored in memory by a microprocessor system. Up to 4000 bubbles may be collected for the determination of each bubble size distribution. The authors describe the optical detection system, the supporting electronics and the computer program used to analyse the data. Typical results from this system are presented.
{"title":"A method for measuring the sizes of bubbles in two- and three-phase systems","authors":"E. W. Randall, C. M. Goodall, P. M. Fairlamb, P. Dold, C. O'Connor","doi":"10.1088/0022-3735/22/10/005","DOIUrl":"https://doi.org/10.1088/0022-3735/22/10/005","url":null,"abstract":"A method is described for measuring the sizes of bubbles in two- and three-phase systems. The length and velocity of each bubble is measured by a pair of optical detectors in a brass block surrounding a capillary tube through which bubbles are drawn. This data is stored in memory by a microprocessor system. Up to 4000 bubbles may be collected for the determination of each bubble size distribution. The authors describe the optical detection system, the supporting electronics and the computer program used to analyse the data. Typical results from this system are presented.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"21 1","pages":"827-833"},"PeriodicalIF":0.0,"publicationDate":"1989-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80065709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-10-01DOI: 10.1088/0022-3735/22/10/009
M. Marconi, J. Rocca, G. Krausse
A technique for rapid gating of the gain of a windowless dual-multichannel-plate-intensified array detector is described. A DC bias applied to the plates allows effective switching of the gain with a relatively low-voltage (500 V) pulse. The pulse is generated by discharging 50 Omega transmission lines through a single fast MOSFET. The pulser characteristics and the dependence of the intensifier sensitivity on the applied voltage are discussed. The apparatus was used to obtain time-resolved extreme ultraviolet spectra with an optical aperture time of about 5 ns.
{"title":"Fast gating of a windowless dual-multichannel-plate-intensified array detector","authors":"M. Marconi, J. Rocca, G. Krausse","doi":"10.1088/0022-3735/22/10/009","DOIUrl":"https://doi.org/10.1088/0022-3735/22/10/009","url":null,"abstract":"A technique for rapid gating of the gain of a windowless dual-multichannel-plate-intensified array detector is described. A DC bias applied to the plates allows effective switching of the gain with a relatively low-voltage (500 V) pulse. The pulse is generated by discharging 50 Omega transmission lines through a single fast MOSFET. The pulser characteristics and the dependence of the intensifier sensitivity on the applied voltage are discussed. The apparatus was used to obtain time-resolved extreme ultraviolet spectra with an optical aperture time of about 5 ns.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"20 1","pages":"849-852"},"PeriodicalIF":0.0,"publicationDate":"1989-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73796917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-10-01DOI: 10.1088/0022-3735/22/10/019
R. Grard, D. Klinge, S. Klimov, S. Savin, J. Trotignon
The Phobos-2 spacecraft has been inserted in a Mars orbit to rendezvous with one of the two Martian satellites, Phobos, in early 1989. The Plasma Wave System (PWS) is part of the scientific payload; this instrument will record, for the first time in a Martian environment, the spectra of natural waves with an electric dipole in the frequency range 0-150 kHz and measure the ionospheric plasma density distribution with a Langmuir probe. In-flight data show that the system performs well and that PWS should meet its scientific goals.
{"title":"The Plasma Wave System on Phobos","authors":"R. Grard, D. Klinge, S. Klimov, S. Savin, J. Trotignon","doi":"10.1088/0022-3735/22/10/019","DOIUrl":"https://doi.org/10.1088/0022-3735/22/10/019","url":null,"abstract":"The Phobos-2 spacecraft has been inserted in a Mars orbit to rendezvous with one of the two Martian satellites, Phobos, in early 1989. The Plasma Wave System (PWS) is part of the scientific payload; this instrument will record, for the first time in a Martian environment, the spectra of natural waves with an electric dipole in the frequency range 0-150 kHz and measure the ionospheric plasma density distribution with a Langmuir probe. In-flight data show that the system performs well and that PWS should meet its scientific goals.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"21 1","pages":"656-662"},"PeriodicalIF":0.0,"publicationDate":"1989-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87538301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-10-01DOI: 10.1088/0022-3735/22/10/018
M. Wilson, S. Ichikawa
A novel instrument under development for the measurement of work functions, which utilises a semiconductor field-effect probe, is presented. The instrument is intended to provide a simple, non-mechanical and non-intrusive method for measuring work functions that can operate in liquids, in vacuo or at high pressures.
{"title":"Field-effect probe for work function measurements","authors":"M. Wilson, S. Ichikawa","doi":"10.1088/0022-3735/22/10/018","DOIUrl":"https://doi.org/10.1088/0022-3735/22/10/018","url":null,"abstract":"A novel instrument under development for the measurement of work functions, which utilises a semiconductor field-effect probe, is presented. The instrument is intended to provide a simple, non-mechanical and non-intrusive method for measuring work functions that can operate in liquids, in vacuo or at high pressures.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"1 1","pages":"886-887"},"PeriodicalIF":0.0,"publicationDate":"1989-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89602774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-10-01DOI: 10.1088/0022-3735/22/10/013
P. Ligrani, B. Singer, L. Baun
A miniature five-hole pressure probe is described which has a probe tip diameter of 1.22 mm. The probe was developed to measure three mean velocity components using a non-nulling procedure at individual locations in a curved channel where differential pressures are low, flow is three-dimensional and laminar, and spatial resolution and flow blockage effects are important considerations. Calibration coefficients are presented for Reynolds numbers based on probe tip diameter ranging from 80 to 400. Coefficients for yaw angle, pitch angle, total pressure and total minus static pressure are independent of Reynolds number within experimental uncertainties. Experimental details unique to the use of the miniature probe are also given along with distributions of mean velocity and mean vorticity over a portion of the 12.7 mm*508.0 mm cross section of a curved channel. At a Dean number of 119 (mean streamwise velocity approximately 1.2 m s-1), structural characteristics of Dean vortices are evident from contours of the streamwise velocity, the total pressure and the streamwise component of mean vorticity determined from secondary flow vectors.
描述了一种微型五孔压力探头，探头尖端直径为1.22 mm。该探头用于测量弯曲通道中不同位置的三个平均速度分量，其中压差低，流动是三维和层流的，空间分辨率和流动阻塞效应是重要的考虑因素。给出了基于探头尖端直径范围为80 ~ 400的雷诺数的校正系数。在实验不确定度范围内，横摆角、俯仰角、总压和总负静压的系数与雷诺数无关。实验细节独特的微型探头的使用也给出了平均速度和平均涡量的分布在12.7毫米*508.0毫米的弯曲通道的横截面的一部分。在Dean数为119时(平均流速度约为1.2 m s-1)，从二次流矢量确定的流速度、总压和平均涡量的流向分量的等高线可以明显看出Dean涡的结构特征。
{"title":"Miniature five-hole pressure probe for measurement of three mean velocity components in low-speed flows","authors":"P. Ligrani, B. Singer, L. Baun","doi":"10.1088/0022-3735/22/10/013","DOIUrl":"https://doi.org/10.1088/0022-3735/22/10/013","url":null,"abstract":"A miniature five-hole pressure probe is described which has a probe tip diameter of 1.22 mm. The probe was developed to measure three mean velocity components using a non-nulling procedure at individual locations in a curved channel where differential pressures are low, flow is three-dimensional and laminar, and spatial resolution and flow blockage effects are important considerations. Calibration coefficients are presented for Reynolds numbers based on probe tip diameter ranging from 80 to 400. Coefficients for yaw angle, pitch angle, total pressure and total minus static pressure are independent of Reynolds number within experimental uncertainties. Experimental details unique to the use of the miniature probe are also given along with distributions of mean velocity and mean vorticity over a portion of the 12.7 mm*508.0 mm cross section of a curved channel. At a Dean number of 119 (mean streamwise velocity approximately 1.2 m s-1), structural characteristics of Dean vortices are evident from contours of the streamwise velocity, the total pressure and the streamwise component of mean vorticity determined from secondary flow vectors.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"32 1","pages":"868-876"},"PeriodicalIF":0.0,"publicationDate":"1989-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74605005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-10-01DOI: 10.1088/0022-3735/22/10/014
K. Oh, C. Ong, B. Tan
A simple thermal control unit, together with a transmission microwave bridge have been constructed for the measurement of electrical conductivity at the X-band frequency of a silicon sample in the range 323 to 573 K. The temperature dependence of the conductivity and hence the band gap of Si were obtained. The technique may be used for other semiconducting materials.
{"title":"A thermal control unit for microwave measurements of conductivity of a semiconducting material","authors":"K. Oh, C. Ong, B. Tan","doi":"10.1088/0022-3735/22/10/014","DOIUrl":"https://doi.org/10.1088/0022-3735/22/10/014","url":null,"abstract":"A simple thermal control unit, together with a transmission microwave bridge have been constructed for the measurement of electrical conductivity at the X-band frequency of a silicon sample in the range 323 to 573 K. The temperature dependence of the conductivity and hence the band gap of Si were obtained. The technique may be used for other semiconducting materials.","PeriodicalId":16791,"journal":{"name":"Journal of Physics E: Scientific Instruments","volume":"9 1","pages":"876-879"},"PeriodicalIF":0.0,"publicationDate":"1989-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74447745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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