Changes

The original LED available to the group was the blue QT Optoelectronics MV5B60. The calibrating this device with the HPD showed a very long decay of its pulse. Several more devices with larger wavelengths were procured and measured settling on a yellow LED (Fairchild MV8304) for its speed. The SiPMs were characterized with respect to one another and the HPD using this device. With a mean wavelength of about 590nm, this LED is near the peak of the SiPM detection spectra.

The original LED available to the group was the blue QT Optoelectronics MV5B60. The calibrating this device with the HPD showed a very long decay of its pulse. Several more devices with larger wavelengths were procured and measured settling on a yellow LED (Fairchild MV8304) for its speed. The SiPMs were characterized with respect to one another and the HPD using this device. With a mean wavelength of about 590nm, this LED is near the peak of the SiPM detection spectra.

By the time more detailed studies of the SSPM-06~ were initiated a fast enough device very close the the mean emission wavelength of the BCF-20 was found. This was the Agilent (Avago Technologies) HLMP-CE30-QTC00. It's time width is somewhat larger than the convenient 100ns window that is convenient for data acquisition (explained below), but accurate data can be derived by centering the window at the same spot for every trial.

By the time more detailed studies of the SSPM-06~ were initiated a fast enough device very close the the mean emission wavelength of the BCF-20 was found. This was the Agilent (Avago Technologies) HLMP-CE30-QTC00. Its time width is somewhat larger than the convenient 100ns window that is convenient for data acquisition (explained below), but accurate data can be derived by centering the window at the same spot for every trial.

== Data Acquisition ==

== Data Acquisition ==