Master Plots of CsI Crystal

Light Output Uniformity

Before and After Painting

The number of photoelectrons per MeV and uniformity of three crystals have been measured, using three different preparation methods. The first method involves wrapping the crystal in two layers of teflon and one layer of mylar. The second is the same as the first, except that the surface of the crystal is painted with the Ukraenian wavelength shifting lacquer. The third method of preparation involves painting the surface of the crystal with the lacquer and wrapping the crystal in one layer of mylar. These preparation methods have been abbreviated "1", "2", and "3" respectively, and have been appended to the appropriate data file names and graph titles.
The number of photoelectrons per MeV (N) was calculated from the slope of a graph of sigma squared vs. energy for each crystal. N was measured for S003 in treatments 1-3, S125 in treatments 1-2, and S128 in treatments 1-3 with the following results, including temperature corrections:
S003-1b: 113, 104
S003-2a: 67, 75
S003-3a: 65
S125-1a: 39
S125-2a: 57
S128-1a: 56
S128-2a: 68
S128-3a: 51,56
The error in these measurements was found to be on the order of 10 photo electrons per MeV.
Next, the light output uniformity of each crystal was measured. S003 has been analyzed in treatments 1-3, S125 in treatments 1-2, and S128 in treatments 1-3. For each crystal and each treatment, scatter plots of axial, transverse, and two dimensional uniformity are shown below. For axial uniformity, the first scatter plot includes all muon path lengths, the second contains only muons with path lengths greater than 5 cm, and the third contains muons with path length less than 5 cm. For transverse uniformity, the first scatter plot describes the entire crystal, while the next four plots involve specific regions of the crystal along the z-axis. The slopes of the scatter plots are shown below, in the following order: Axial(0:10cm), Axial(10:18cm), Axial(18:22cm), Transverse(z=2:4cm) Left, and Transverse(z=2:4cm) Right.
S003-1a: -1.48 -2.36 -1.59
S003-1b: -1.306, -2.719, +1.306, -2.388, -2.295
S003-2a: -2.322, -0.841, +2.813, -2.753, +1.210
S003-3a: -2.844, -1.686, +2.526, -1.205, -6.556
S125-1a: 1.74 1.03 -3.39
S125-2a: +1.235, +1.111, -3.433, -0.158, -1.159
S128-1a: 0.08 -1.22 0.73
S128-2a: +0.334, +0.219, +1.231, +0.363, +0.044

s003-1b s003-2a s003-3a s125-1a s125-2a s128-1a s128-2a s128-3a

P. Slocum, E. Frlez, 13 Mar 1996