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outputs from this module was sent to an Channel 2 of the Logic Fan-in/Fan-Out (delayed
oscilloscope to visualize the signals of the detector. logic pulse) is used as the START input to trigger the
Another output was sent to a discriminator, which TAC (Time to Amplitude Converter). The START
sets a lower cutoff for the signals. signal needs to be delayed so that no pulse is still
present in the STOP line when a new START pulse
arrives; in other words, the delay is applied to
prevent signals from piling up in the TAC.
Another output from Channel 1 of the Logic Fan-
in/Fan-Out (original signal discriminated), is sent to
the Coincidence Unit, where it will be compared
with the gate generated by the delayed signal.
Notice that, since this gate is delayed 140 , the
first pulse from the original not-delayed signal, will
be out of coincidence, and therefore we won’t be
making coincidence of a pulse with itself. Further-
more, the second pulse of the original not-delayed
signal (associated with the electron produced
Figure 1. Cylindrical Scintillator employed for the first part when the muon decays), won’t be left out of
of the experiment. coincidence, because this second pulse will be
Figure 2. Logic circuit layout. delayed relative to the first one by about 2
(which is the expected decay time), while the gate
The output of the discriminator was then sent to is only behind by 140 from the first pulse. This
Channel 1 of a Logic Fan-in/Fan-Out producing configuration of the pulses guarantees that when
multiple identical signals. One of those outputs was we get a coincidence, it will be because of the
sent to a delay box, were a 140 delay was decay of a muon.
applied before being sent to the Channel 2 of the
Logic Fan-in/Fan-Out. One of the corresponding Fig. (3) helps understand the configuration of the
identical outputs of this signal is sent to a Gate & signal. Channel 1 (yellow) in the oscilloscope shows
Delay Generator, where it is converted into a gate the original analog signal coming from the PMT; as
pulse of 10 of width, to then be sent to a we can see there are two pulses, the first one
Coincidence Unit. Another identical output from corresponds to the arrival of the muon to the
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Año 10 Núm. 30 septiembre-diciembre 2024 Tlahuizcalli ISSN: 2448-7260
