Initial Tests Of The Pion Beta Decay Detector

4.2.2 Photomultiplier tubes

The PMTs used to view the signals coming from the PV were Burle Industries S83062E tubes. The S83062E is a 1" end window PMT with ten stages. The tube is sensitive to light with wavelengths in the range of 300 nm to 660 nm. This PMT has a nominal operating voltage in the range of 1500 V to 1800 V though some were operated at as high as 1800 V to increase the gain during the 1996 and 1997 beam times.

Table 4.1 : General properties of BC-400 organic scintillator (from Bicron Web Site)

Base
Polyvinyltoluene
Density
1.032 g/cm³
Refractive Index
1.58
Coefficient of Linear Expansion
7.8 x 10^-5 , below 67° C
Atomic Ratio, hydrogen:carbon
~1.103:1
Light output relative to anthracene
65%
Rise time
0.9 ns
Decay time
2.4 ns
Hydrogen atomic density
5.23 × 10²² atoms/cm³
Carbon atomic density
4.74 × 10²² atoms/cm³
Electron number density
3.37 × 10²³ /cm³
Light attenuation length
160 cm
Wavelength of maximum emission
423 nm
Light output temperature dependence
At +60°, C=95%
of that at +20° C.
Independent of temperature from
-60° C to +20° C

Figure 4.3: Light output vs. wavelength for BC-400 organic scintillator

Base	Polyvinyltoluene
Density	1.032 g/cm³
Refractive Index	1.58
Coefficient of Linear Expansion	7.8 x 10^-5 , below 67° C
Atomic Ratio, hydrogen:carbon	~1.103:1
Light output relative to anthracene	65%
Rise time	0.9 ns
Decay time	2.4 ns
Hydrogen atomic density	5.23 × 10²² atoms/cm³
Carbon atomic density	4.74 × 10²² atoms/cm³
Electron number density	3.37 × 10²³ /cm³
Light attenuation length	160 cm
Wavelength of maximum emission	423 nm
Light output temperature dependence	At +60°, C=95% of that at +20° C. Independent of temperature from -60° C to +20° C