CAPINTEC, INC. CAPTUS
®
600
13:06
OK
ENRGY
MULTICHANNEL ANALYZER
SETUP
ENERGY SCALE : 200 keV
COUNTING TIME :> 60 SEC X
COUNTING TIME BASE: REAL
BASE
CUT OFF CHANNEL : 5
PEAK COUNTS : 100
P/T
Figure 18-6
The MCA counting can stop when the counting time is reached or when the Peak Counts
(i.e. Full Scale Counts) reach a given value. Only one of these options is active. The “X”
indicates that Counting Time is active.
Input the Counting Time in seconds and Low-level Cutoff Channel. Any input pulses that are
measured below this cutoff channel will be ignored by the MCA. To calculate the cutoff in
keV, divide the desired cutoff in keV by the gain of the energy range selected. The gains for
the energy ranges are as follows:
200 keV scale .......... 1 keV/Channel
400 keV scale .......... 2 keV/Channel
800 keV scale .......... 4 keV/Channel
1600 keV scale .......... 8 keV/Channel
EXAMPLE: For a 40 keV cutoff on the 400 keV full scale range, the desired cutoff channel
is calculated as:
20 =
Channel/ keV2
keV 40
= channel cutoff
Press F1 [ENRGY] to change the Energy Scale from 200 keV to 400 keV to 800 keV to 1600
keV.
Press F2 [BASE] to switch the Counting Time Base between REAL and LIVE (Reference
CHAPTER 3: GENERAL OPERATING OVERVIEW for an explanation of Real and Live
Time).
Press F3 [P/T] to switch between
Peak Counts and Counting Time.
When Peak Counts is selected, the “X” will move from the Counting Time to the Peak Counts
as shown in
Figure 18-7.
18-4 MULTICHANNEL ANALYZER SETUP November 07
To Next Page
Loading...
