Page 96 - Macromolecular Crystallography

IN-HOUSE MACROMOLECULAR DATA COLLECTION 85

Scintillator Light barrier
Fiber optic taper
with a 2.8:1
reduction ratio
4096 × 4096 pixel
CCD array
Scattered
X-rays
Protein
crystal
X-ray

Thermo-electric
(peltier) cooler
Controller
and ADC

X-ray
Light

Figure 5.4 Schematic diagram of a CCD detector. (Reproduced with permission from Nolting, Methods in Modern Biophysics, Springer
Verlag, 2004.)

by Hamlin, Nielsen, and Xuong) and consists of abbreviation for Desk Top Beam line). This assem-
four chips bonded together to make an active area bly is supplied with variable apertures ranging
2
of 210 cm and currently used on many synchrotron from 0 to 5 mm, with 2.5 mm resolution. It also
beamlines around the world. incorporates built-in ion chambers with very wide
dynamic ranges, permitting very precise optimiza-
tion of the beam. Either detector (image plate or
5.6.3 The MAR345 and MARCCD CCD) can be tilted in the vertical to a maximum 2θ
◦
of 30 . For the MAR345, the detector can be driven
Both the MAR345 and the MARCCD are sup- from 75 to 425 mm and the CCD detector from 20 to
plied with a MARDTB goniostat (DTB being an 370 mm using the MARDTB.