LED Pulsers for MULAN
Preliminary
Installation completed July 20, 2004
A team from JMU installed the final
components.
Basic system (Click in the yellow boxes
for pictures):
1. KAMLAND based
LED boards (circuit).
·
Small board that is
imbedded close to the pmt. A mounted Led flashes in response to trigger pulses.
The brightness is adjustable by changing a voltage (B+) .
·
A simplified circuit shows the charging voltage B+ and
the switches t1 and t2 which close on a trigger pulse discharging a capacitor
through an LED.
·
Pulsers are set to
produce about 100 photoelectrons. This is a B+
voltage of about 8V. The boards vary a by few volts above and below the nominal
value.
·
The LEDs
produce a signal on a PMT that is comparable to a particle.
MAX rate ~ 100 kHz
· 100 KΩ x 22 pF=
2.2μs
1/τ = 455 kHz
2. Driver boxes
3. Flight
Simulator
4. Fiber optic
link and mounting of LED boards
5. Computer
control of FS (MIDAS and DAQ)
Users Manual:
Operation and Repair Guidelines
Previous Commentary on the development and
production.