National Instruments Digitizer VI
From Physics 111-Lab Wiki
Muon Lifetime - Acquire Data.vi Overview
First you need to start the ViewSignals program and analyze the input Muon signals from the PMT. See below for description of program.
After you have determined the settings for the Muon Lifetime Acquire Data Front Panel program then you can stop acquistions for the ViewSignals program and start the main program “Muon Lifetime Final Version 1.0”. These two program short cuts are on your Desktop of the computer.
The two programs can NOT be running both at the same time.
== To use the Muon programs Description of Muon Programs and Setup Muon_Program_Description
NOTE:
When you want to stop the program, their is a sequence to stop or your data will not be saved. Stop acquistion early button must be pushed once 1st then go to the top menu and push stop, the Red button of the main program. The save data for the network drive is only saved at the end of the normal termination of the program and only after the "Stop Early" button has been pushed 1st before the Main program Stop button.
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The vi tells the digitizer to acquire data. It then looks for one pulse meeting the first pulse threshold. If there is such a pulse, it looks for a second pulse meeting the second pulse threshold, such that the time difference between the two pulses is within the range and the time of the second pulse is greater than the sum of the time of the first pulse and a delay time. If two pulses exist, the vi records the time difference between the pulses, the amplitude of the first pulse, the width of the first pulse, the amplitude of the second pulse, and the width of the second pulse. The time information is taken off the signal before it is passed through a low-pass filter. The amplitude and width information is passed after the signal is passed through a low-pass filter. The width is the full-width-half-max.
The vi acquires data and looks for pulses for a set acquisition time. During this acquisition time, a real time histogram of the time intervals is plotted on the front page. Once the acquisition time has passed, the vi saves the raw data (time interval, pulse 1 amplitude, pulse 1 width, pulse 2 amplitude, pulse 2 width) to the end of a file. This raw data file accumulates the raw data for every acquisition. The vi then takes this raw data file and makes histograms of each category. The vi saves this data to another file, and plots a summed histogram of the time intervals on the front page.
When the number of acquisitions is equal to the number of acquisitions control set on the front page, the vi stops acquiring data, and saves the pulse 1 count and pulse 2 count to the raw data file.
