LW Detector

General Specs

Thin lead sheet converts gamma rays to e plus / e minus pairs which create cherenkov radiation in the areogel in the head of the detector. A light tight 10 x 10 cm pipe lined with aluminium coated mylar guides the cherenkov radiation to a PMT at floor level (far from the beam level). The PMT is also shielded for additional protection. The detector is operated at 1250V and a 30 m heliax cable is used to relay the signal to the LW Hut where the signal is first attenuated and then digitised by a gated 14 bit ADC.

• 7.3 mm lead (optimal thickness) - see LD's thesis
• 4 x layers of 5 x 5 x 1 cm Aerogel - unknown whether single layer best
• Hamamatsu R887
• Typical attenuation 8 - 16 dB

Diagrams

• 20101106 Detector #2 - PMT photos and description

• Photo Album of Detector

History