Spring 2002  (Status )

The pulser is a blue LED mounted on a printed circuit board. A trigger pulse causes a capacitor to discharge through the LED creating a light flash.  The pulser will be controlled via a driver box which will provide board power, adjustable capacitor charging voltage and a trigger translator that sends a TTL pulse to fire the LED. A description of some of the details of the board and the driver circuit follow.

The summer 2002 run used KAMLAND pulser boards that were built at Berkley by the B. Lauss.  These were installed in the 48 positron detectors and controlled by JMU drivers. The drivers were designed and built by a team of JMU undergraduates:

Charlie Arnold, Andrew Werner and Rick Wiita.

The pulsers and drivers need further development.  Reducing the pulse width and eliminating after-pulsing are sought after improvements for the pulser boards. Drivers had some faulty power supplies and some bad channels that  need to be corrected.

Details based on the ongoing development are presented below.

JMU in preparation for the upcoming PSI test run is working on a pulser to drive Kamland style LED’s.

The current plan is to provide a pulser driver that connects via an individual cable to each pulser. A sketch of the pulser board is shown below.  (KAMLAND pulser circuit diagram.)

 

 

 

 

 

 

(Sample pulser shown above one is viewing the side without the lettering. The diode is attached to the opposite side.)

 

 

Required signals:

·        24 V

·        5 V

·        -5V

·        gnd

·        trigger (Currently differential TTL) twisted pair 120Ohm termination.

The ribbon cable will be brought to the Hex house top wall. A Shrouded header attached to the ribbon cable will be mounted by screws to the house top wall.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Measurements in iches.

Use standard twisted pair 10pin header connectors from the driver to feed thru. Each pulser would have a 10 connector cable (1ft long) soldered to pulser  attached to feed thru. A picture of the style of cable that I am considering is below.

 

 

 

 


 

 

 

Sketch of the box shown below. Box dimensions are roughly - 8” wide x 2.75” tall x 11” long. There will be a Swiss power cord out the backside. Box details.

 

 

 

 

 

 

 

 

 

 

3D version (1 )

To keep the cabling straight the connections run as shown below