Ubitekk CC1, User Manual

9

Because accidentals can sometimes obscure the true correlations being sought in an 
experiment, it can be advantageous to have these accidentals automatically calculated and 
subtracted from the measured coincidence value. 

The Subtract Acc.? setting allows the user to turn this calculation on or off. If the Subtract Acc.? 
value is set to “YES,” then the estimated accidentals will be calculated and subtracted from all 
coincidence measurements. If the Subtract Acc.? value is set to “NO,” then the full coincidence 
counts (with accidentals included) will be reported. 

2.6 Trigger 

The Trigger setting allows the user to select how a measurement will be started and stopped. If 
the Trigger setting is set to “Continuous,” then the measurements will start once the ON/OFF 
button is pressed. Once a count is initiated, the unit will accumulate counts for the set Dwell 
Time. Once the Dwell Time has been reached, the total counts accumulated will be shown on 
the counter’s display for a short period of time. Then the unit’s counters will automatically be 
reset and a new count initiated. This cycle will continue over and over until the ON/OFF button 
is again pressed to halt continuous triggering. 

If the Trigger setting is set to “Start/Stop” then a new count will be initiated only when the 
ON/OFF button is pressed. Once a count is started, the count will continue until either the dwell 
time is reached or the ON/OFF button is pressed again to stop the counting cycle. 

2.7 CH1 

Delay 

The signal coming into the Channel 1 connector can be delayed by adjusting the “CH1 Delay” 
setting. Adding a delay to a channel can be useful when searching for coincident events in 
signals that may be delayed. For example, if the cable from one photon detector is one meter 
long while the cable from a second photon detector is two meters long, then there will be a 
transmission delay of roughly 5 ns that must be subtracted to detect coincident events.  

The CH1 delay setting allows delays of 0, 2, 4, 6, 8, 10, 12, and 14 ns to be programmed into 
the CC1.  

2.8 Firmware 

Ver. 

The firmware version is a four digit identifier of the CC1’s firmware release version. This setting 
cannot be changed by the user.