V a r i o u s e l e c t r i c a l a l i g n m e n t t e s t s t r u c t u r e s were designed t o conform t o t h e NBS 2 X N probe pad a r r a y and a r e t h u s c o m p a t i b l e w i t h a c l a s s o f other modular t e s t s t r u c t u r e s . The o b j e c t of t h i s study i s t o d e t e r m i n e t h e f e a s i b i l i t y 7B 2.1 7F 2.1
1. INTRODUCTION 1 2. BACKGROUND. 3. MULTIMETER OPERATING PRINCIPLES AND APPLICATIONS 3.1. Basic Modern Digital Multimeter Design 3.1.1. DC Voltage Measurements 3.1.2. AC Voltage Measurements 3.1.3. Resistance Measurements 3.1.4. Current Measurements 3.1.5.
Recent measurement by Emery and Rabson 1 of €, the mean energy required to create an electron-hole pair with 207 Bi conversion electrons at 20°K in lithium-compensated silicon, resulted in a surprisingly high value of 5.22 ±0.02 eV. Previous measurement of the relative pulse height of 207 Bi conversion electrons with the use of surface barrier detectors of 3000 and 6700 fi-cm resistivity silicon by Dodge et al. 2,s indicated that e was very close to its room-temperature value of approximately 3.6 eV in the temperature interval 4.2-12°K. More recent measurements of e at 4.2°K by Fabjan, Kenawy, and Rauch 4 are in good agreement with the measurements of Dodge et al.The measurements of Emery and Rabson together with the measurements of Dodge et al. would imply that e exhibits a sharp peak at a temperature between 12 and 20°K. The existence of such a peak would be embarrassing to the existing theory of c. 5 The theory relates e to the band-gap energy Eg, the ratio X z -/x# of the mean free paths between ionizing and phonon collisions, and the phonon energy HUR at the Raman frequency, by the following expression:None of these quantities is expected to exhibit rapid variation with temperature. Furthermore, although Dodge et al. observed attenuated pulse heights in both lithium-compensated and nonlithium-compensated silicon detectors in the temperature interval around 20°K, these attenuated pulse heights were not interpreted as due to first-order changes in e. In the case of nonlithium-compensated silicon, the attenuated pulse heights were attributed by Dodge et al. to the long dielectric relaxation time of the undepleted silicon. This assumption successfully explained their extensive experimental data. The mechanism responsible for the attenuation of pulse heights from lithium-compensated silicon detectors was not experimentally explored in detail but was thought to be due to some less interesting process than a change in €. The possibility of structure in £ as a function of temperature together with the implicit disagreement between the results of previous measurements provide justification for the remeasurement of e reported here.Measurement of e as a function of temperature was carried out with the use of the cryostat shown in Fig. 1. A copper disk suspended from the top of the sample-space vacuum container by two thin-walled stainless-steel tubes served as a heat sink for the detector. Four carbon resistors were symmetrically embedded in the disk; two of the resistors were used as thermometers and two were used as heaters to elevate the temperature of the detector-heat-sink system above 4.2°K. The temperature of the copper heat sink was measured
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.