Preamplifier mounting

In some cases, it may be necessary to position shielding or other detectors behind the detector itself (for example, in an anti-Compton spectrometer system - see Chapter 13). For this purpose, detector systems are available with the preamplifier mounted close to the dewar leaving a clear length of cold finger between it and the detector. 

The ( harge from the diode will be collected with a charge sensitive preamplifier, mounted in close proximity to the diode. Both the diode and the preamplifier wall be shielded to eliminate electronic noise pickup. The required noise characteristics of the preamplifier... 

The first 3 items of the above list (waveguides, transducers and preamplifiers) are located at or near to the component(s) to be monitored. The other items must be installed in the control room area, mounted into a single instrumentation rack (fig. 4). 

The 6 Nd YAG lasers pump the DM0, preamplifier and power amplifier (Fig. 19, Friedman et al., 1998). The YAG lasers are built from commercially available flashlamp/laser rod assemblies, acousto-optic Q-switches and frequency doubling crystals (LBO and KTP). Most of the mirror mounts and crystal holders are commercial. Nd YAGs are frequency doubled to 532 nm using a nonlinear crystal. The Nd YAG rod and nonlinear crystal are both in the pump laser cavity to provide efficient frequency conversion. The 532 nm light is coupled out through a dichroic and fed to multimode fibers which transport the light to the DM0 and amplifier dye cells. 

Adjustable Workbench (PAW) instrument assembly. The SH shown in Figs. 3.15 and 3.16 contains the electromechanical transducer (mounted in the center), the main and reference Co/Rh sources, multilayered radiation shields, detectors and their preamplifiers and main (linear) amplifiers, and a contact plate and sensor. The contact plate and contact sensor are used in conjunction with the IDD to apply a small preload when it places the SH holding it firmly against the target. The electronics board contains power supplies/conditioners, the dedicated CPU, different kinds of memory, firmware, and associated circuitry for instrument control and data processing. The SH of the miniaturized Mossbauer spectrometer MIMOS II has the dimensions (5 x 5.5 x 9.5) cm and weighs only ca. 400 g. Both 14.4 keV y-rays and 6.4 keV Fe X-rays are detected simultaneously by four Si-PIN diodes. The mass of the electronics board is about 90 g [36],... 

Once closed inside its copper frame, the array was mounted and thermally connected to the mixing chamber of the Oxford DR installed in Hall A of the underground Gran Sasso National Laboratory. The tower was mechanically decoupled from the cryostat in order to avoid vibrations induced by pumps on the detectors and preamplifiers [98],... 

Fig. 12.4. Single-tube STM. The tube piezo scanner is adhered inside a sturdy metal cylinder, which sits on three screws on the base plate. The two front screws make the coarse approaching. The rear screw makes fine approaching by using the two front screws as the pivot axis. The rear screw is actuated by a stepping motor for automatic approaching. The preamplifier (not shown) is mounted directly on top of the metal cylinder to eliminate the microphone effect of the coaxial cable between the tip and the input of the preamplifier. The entire unit is rigid enough that a mediocre vibration isolation device can provide atomic resolution. (After Hansma et al., 1988.)...

E is the energy of characteristic X-ray line and Fisa constant called the Fano factor, which has a value of 0.12 for Si(Li). electronic noise factor, plays an important role in the resolution. Reduction of the electronic noise will improve the resolution of the EDS detector. Thus, the Si(Li) diode and the preamplifier are mounted in a cylindrical column (the cryostat) so that they can operate at the temperature of liquid nitrogen (-196°C) in order to reduce the electrical noise and increase the signal-to-noise ratio. 

Mounting the He-3 detector and preamplifier on the KE remotely operated flapper carriage for confirming ruptures. 

The construction of the bolometer is shown in Fig. 1.31. The thermally isolated tank is filled with liquid nitrogen as precooler and with liquid helium as cooling medium. When the evaporated vapour above the liquid helium surface is pumped away, evaporation cooling drops the temperature down to about 1.5 K. The semiconductor detector (Fig. 1.32) with a preamplifier is mounted on the bottom of the... 

With the high-frequency system, preamplified sonic vibrations drive a dynamic diffusor in which the dust-covered plate is mounted. Here the vibration frequency is no greater than 3 kHz, and the detaching force may be as great as 2500 g-units. 

Antenna preamplifier A small ampHfier, usually mast-mounted, for amplifying weak signals to a level sufficient to compensate for down-lead losses. 

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