Diamond Detectors for Ionizing Radiation - HEPHY

CHAPTER 8. DETECTOR GEOMETRIES 50
300 V
641 µm
(a)
0V
1.0 1.5 1.75 2.0 r [mm]
300 V
0V
641 µm
(b)
0V
Figure 8.2: Cross-section of a diamond sample, showing potentials and the electric eld without
(a) and with (b) a grounded guard ring.
the digital (or, binary) resolution RMS of
RMS dr =
p p
12
: (8.1)
When the strip pitch is small enough, charge sharing between two or more electrodes
occurs, and together with proper analysis tools, the particle track can be reconstructed
with much higher resolution than digital, depending primarily on the SNR. Using a silicon
detector (300 m thick) with a strip pitch ofp=50m and a high-quality amplier (e.g.,
the VA2), it is easy to obtain a spatial resolution of a few micrometers.
8.2.2 Measurements
When a diamond strip detector is measured in a test beam, the particle track is monitored
with a number of high-resolution silicon strip reference detectors. Half of the reference
detectors are rotated by 90 in order to obtain x and y position information. A system of
such detectors, shown in g. 8.3, is called \beam telescope". The RD42 telescope utilizes
8 planes of silicon strip detectors with a pitch of50m, which are read out by VA2 chips.
The intrinsic resolution of this telescope is approximately 1:5 m.