8
9. Each quantity is expressed in keV FWHM. The
quantity N
det
is known as the "noise width" of the
detector, and is included as one of the specified
parameters. By use of the above equation and with
a knowledge of the noise of the preamplifier, the
noise width of the detector can be determined. The
significance of this noise width in evaluating the
detector is subject to interpretation, but generally
the actual resolution of the detector is related
directly to the noise width in its normal applications.
The most useful purpose for determining this
quantity for the detector is occasional monitoring of
the detector noise width to verify that its
characteristics have not undergone any significant
change during use.
10. Use an ORTEC 419 Precision Pulse Generator
with a matched charge termination to measure the
rise time of the 142PC through the T or E output
connector. Connect the 419 output through the
charge terminator to the input of the 142PC and use
an oscilloscope with a fast (1 ns if possible) rise
time. The rise time of the preamplifier can then be
computed by:
(Total risetime)
2
= (Preamp risetime)
2
+ (Pulser risetime)
2
+ (Oscilloscope risetime)
2
.
The risetime of the 419 is typically 3 ns.
5.2. FACTORY REPAIR
This instrument can be returned to ORTEC for
service and repair at a nominal cost. Our standard
procedure for repair ensures the same quality
control and checkout that are used for a new
instrument. Always contact the Customer Service
Department at ORTEC, (865) 482-4411, before
sending in an instrument for repair to obtain
shipping instructions and so that the required
Return Authorization Number can be assigned to
the unit. Write this number on the address label and
on the package to ensure prompt attention when it
reaches the factory.
Summary of Contents for 142PC
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