Figure 54. Example Showing Kinetics Operation Using "Multiple Trigger - Princeton Instruments PhotonMAX System Manual

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Chapter 6

In multiple trigger mode, each "exposure-shift" cycle is triggered independently. This

mode is useful when each subframe needs to be synchronized with a pulsed external light

source such as a laser.

Trigger In

Exposure/

Subframe

Vertical Shift

Readout

Note: It is particularly important to keep ambient light to a minimum while multiple

trigger mode is used. In the case of this mode, automatic cleaning of the CCD only occurs

until the first trigger arrives. Once the series of "exposure-shift" cycles begins, cleaning

does not occur and, at the end of a cycle, ambient light will be collected through the

window until the next trigger arrives. Depending on the time between triggers and the

amount of ambient light, some subframes may appear brighter than others.

Cleaning the CCD

Since kinetics is most often used in asynchronous, single-shot experiments, it is important

that CCD be cleared of accumulating background or dark charge while it is waiting for an

external trigger. To take care of this, PhotonMAX automatically cleans the CCD "one

row at a time" before the arrival of the first trigger. This keeps the charge buildup on the

CCD to a minimum at the same time minimizing the timing jitter (determined by vertical

shift time of a single row). If desired, the number of cleans can be set to zero for the best

jitter performance. However, the camera must be in dark environment to minimize the

background.

Advanced Topics

exp

Figure 54. Example showing Kinetics Operation using "Multiple Trigger"

exp

~500 msec @1 MHz readout

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