Multichannel analyser input

To eliminate the need for recalibration during a measurement and to obtain additional information, the Royco instrument was supplemented with a Nuclear Data ND-60 Multichannel Analyser (MCA). The amplified signal of the Royco 225 (which is proportional to the cimount of light scattered from each particle) was connected to the input of the MCA which cem count and classify pulsed input signals into as many as 2048 channels and display the results on a cathode ray tube (CRT). This number of cells is of course much more than required to determine the PSD. The data were therefore grouped into eleven cells whose limits were consistent with those used earlier (5), emd the counts in these cells were then printed on a Texas Instruments 743 KSR Data Terminal interfaced with the MCA. 

Figure Bl.10.7. Electron impact ionization coincidence experiment. The experiment consists of a source of incident electrons, a target gas sample and two electron detectors, one for the scattered electron, the other for the ejected electron. The detectors are connected through preamplifiers to the inputs (start and stop) of a time-to-amplitude converter (TAG). The output of the TAG goes to a pulse-height-analyser (PHA) and then to a multichannel analyser (MGA) or computer.

Multichannel Analyser. Records a histogram of the frequency of the input pulses versus the amplitude. 

A typical PEPICO apparatus is shown in Figure 1, where an acceleration region followed by a drift tube is used to determine the ionic species. The coincidence condition is achieved by using electron and ion signals as start and stop inputs, respectively, to a time-to-pulse height converter whose output is sent to a multichannel pulse height analyser. 

RBMK reactors have large cores, where local effects play a significant role in safety analyses of the several initiating events. For this reason, it is appropriate to use a 3-D neutronics code with a built-in multichannel thermohydraulic model. In addition, a 3-D neutronics code should be employed for compiling input data for point neutron kinetics (commonly involved in thermohydraulic codes) when events such as LOCAs are analysed. 

For the routine experiments of two TRIGA reactors and the commissioning experiments of the new 30 MW HANARO research reactor in the Republic of Korea, a stand alone system, with input signals independent from the reactor operation and safety chaimels, is configured. This system has been utilized for the criticality approach, real time reactivity measurement, noise analyses, control rod drop time measurement, and thermal power calibration in a natural convection cooled reactor. It replaces conventional counter modules for the criticality measurement, multichannel analyzer and... 

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