LUDLUM 3030, Manual

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Model 3030 & 3030E Series Technical Manual
Section 7
Ludlum Measurements, Inc. Page 30 November 2017
4. Enter the “Starting High Voltage” and the “Ending High Voltage.”
These parameters define where the plateau will start and end.
5. Enter the “High Voltage Step.” This parameter determines the
increment between steps in the plateau.
6. Enter the “Alpha Source Size” and “Beta Source Size.” There are
three fields for each channel corresponding to CPM, DPM, and
µCi. The user can enter the source size in any field, and the
other fields will automatically show the converted value. It is
preferred to use the DPM or µCi column wherever possible.
Conversion from CPM to DPM using a factor of 2 may not be
correct depending on isotope and source material. Under the
“ISOTOPE” fields, enter the isotope label for the alpha and
beta source.
7. Verify the current count time. The Model 3030 has seven preset
time values and a user-definable “PC” time set by the computer.
The “PC” time is defined in the tab marked “General Settings.”
Enter in the needed time and press “Update.” If a different time
is required, change the time by using the knob on the front of
the instrument and click the “Read” button to refresh the count
time on screen. The background count time is always one
minute.
8. Press the “Start” button to start the plateau. There is a prompt to
insert the alpha source. The Model 3030 will record readings at
each high voltage as determined above. When the alpha plateau
is completed, you are prompted to insert the beta source. Again,
the Model 3030 will record readings at each high voltage. After
the beta plateau is complete, you are prompted to remove the
beta source. Background counts are then taken. The grid
contains the following columns:
1. Alpha source (beta counts shown in parenthesis)
2. Beta source (alpha counts shown in parenthesis)
3. Alpha background in cpm
4. Beta background in cpm
5. % alpha efficiency (4π)
6. % beta efficiency (4π)