Nuclear Medicine Physics and Instrumentation I, Part 1
... • RC circuitry and clock oscillator • Discharging time proportional to the amplitude of the input pulse (radiation energy) • Clock oscillator produces pulse train that are counted in a counting circuit • The number of the clock pulses counted are proportional to the discharging time which in turn pr ...
... • RC circuitry and clock oscillator • Discharging time proportional to the amplitude of the input pulse (radiation energy) • Clock oscillator produces pulse train that are counted in a counting circuit • The number of the clock pulses counted are proportional to the discharging time which in turn pr ...
PMT Circuits
... Operating the PMT in pulse mode runs into the same nonlinearity problem Decoupling capacitors can increase the linear operating region ...
... Operating the PMT in pulse mode runs into the same nonlinearity problem Decoupling capacitors can increase the linear operating region ...
Electricity What you should already know
... a neutral object can attract a - or + charge Current Electricity – continual flow of electrons through a conductor Conductors – materials that electrons can move through easily ex. – copper, gold, silver Insulatorselectrons can’t move easily ex. – wood, cotton, rubber, glass Current (I) is ...
... a neutral object can attract a - or + charge Current Electricity – continual flow of electrons through a conductor Conductors – materials that electrons can move through easily ex. – copper, gold, silver Insulatorselectrons can’t move easily ex. – wood, cotton, rubber, glass Current (I) is ...
J. J. Thomson Determined the charge to mass ratio
... 2. Atoms are indestructible and unchangeable. ...
... 2. Atoms are indestructible and unchangeable. ...
The Electron Charge-to-Mass Ratio Equipment The experiment and
... This experiment investigates the path of an electron in a magnetic field. The apparatus consists of an electron gun contained within a helium filled tube. The cathode and anode are connected to a variable voltage supply ranging between 100-300 volts. The cathode is heated by an electric current, whi ...
... This experiment investigates the path of an electron in a magnetic field. The apparatus consists of an electron gun contained within a helium filled tube. The cathode and anode are connected to a variable voltage supply ranging between 100-300 volts. The cathode is heated by an electric current, whi ...
CHAPTER 11 R-F COMPONENTS BY A. E. WHITFORD 11.1. The
... result is that for long lines either (1) VSWR'S lower than 1.5 are necessary to ...
... result is that for long lines either (1) VSWR'S lower than 1.5 are necessary to ...
Cavity magnetron
The cavity magnetron is a high-powered vacuum tube that generates microwaves using the interaction of a stream of electrons with a magnetic field while moving past a series of open metal cavities (cavity resonators). Bunches of electrons passing by the openings to the cavities excite radio wave oscillations in the cavity, much as a guitar's strings excite sound in its sound box. The frequency of the microwaves produced, the resonant frequency, is determined by the cavities' physical dimensions. Unlike other microwave tubes, such as the klystron and traveling-wave tube (TWT), the magnetron cannot function as an amplifier, increasing the power of an applied microwave signal, it serves solely as an oscillator, generating a microwave signal from direct current power supplied to the tube.The first form of magnetron tube, the split-anode magnetron, was invented by Albert Hull in 1920, but it wasn't capable of high frequencies and was little used. Similar devices were experimented with by many teams through the 1920s and 30s. On November 27, 1935, Hans Erich Hollmann applied for a patent for the first multiple cavities magnetron, which he received on July 12, 1938, but the more stable klystron was preferred for most German radars during World War II. The cavity magnetron tube was later improved by John Randall and Harry Boot in 1940 at the University of Birmingham, England. The high power of pulses from their device made centimeter-band radar practical for the Allies of World War II, with shorter wavelength radars allowing detection of smaller objects from smaller antennas. The compact cavity magnetron tube drastically reduced the size of radar sets so that they could be installed in anti-submarine aircraft and escort ships.In the post-war era the magnetron became less widely used in the radar role. This was because the magnetron's output changes from pulse to pulse, both in frequency and phase. This makes the signal unsuitable for pulse-to-pulse comparisons, which is widely used for detecting and removing ""clutter"" from the radar display. The magnetron remains in use in some radars, but has become much more common as a low-cost microwave source for microwave ovens. In this form, approximately one billion magnetrons are in use today.