126 Ridge Rd., PO Box 187, Lansing, NY 14882
Telephone: (607) 533-3531 Fax: (607) 533-3618

Fluorescent Screen Assembly
FC-204
Figure 1.a – Isometric View of the System
Key Specifications:
Detector Sub-System
Parameter
Travel Range
Total Heat Load
Maximum Heat Flux
Cooling Connections
Minimum Cooling Flow (Water at 20 °C)
Compressed Air Connections
Minimum Air Pressure
Drain Current Connection
Figure 1.b – Longitudinal Cross-Section of the System
Value
50mm [2”]
426 W
2.18 W/mm2
¼” Swagelok
1.5 m/s [0.29 gal/min]
Push-to-Connect ¼”
40 psi
BNC
Description:
Based on a design by Dr. Henry Bellamy, Louisiana State University [for more
information on LSU please visit http://www.camd.lsu.edu/ ], ADC has manufactured the FC-204
unit which allows the user to view the position and profile of an incident X-ray beam. The full
assembly of the fluorescent screen consists of three main components: a welded vacuum
chamber; a linear actuator mounted to one branch of the chamber; and a water-cooled fluorescent
screen. The chamber has 6” CF flanges on the upstream side (non-rotatable) and downstream
side (rotatable) for connecting to the CAMD beamline. The upper branches of the chamber have
4½” CF flanges. One branch is capped by a quartz-glass viewport, while the other supports the
pneumatic actuator used to position the fluorescent screen. Copper tubes provide water-cooling
for the fluorescent screen and have ¼” Swagelok fittings for connecting to the water supply. The
tubes are vacuum brazed into the fluorescent screen. A stainless steel bracket provides structural
ADC Corporation. E-
126 Ridge Rd., PO Box 187, Lansing, NY 14882
Telephone: (607) 533-3531 Fax: (607) 533-3618

support for the screen and cooling tubes. The screen itself is at a 60° angle from the horizontal
plane. The face of the screen is coated with P22R phosphor and features equally spaced grooves
cut into the surface for imaging from the viewport above. The lower hard stop for the pneumatic
actuator allows the screen location to be fine-tuned as needed to place the beam on a flat or a
groove in the grid.
Inventor Simulation was used to perform steady-state thermal analysis on the fluorescent
screen assembly. An average mesh size of 0.6 mm was used for each analysis. A surface heat
flux of 2.18 W/mm2 was applied over the 40 mm x 5 mm beam footprint centered on the
fluorescent face. Figure 2 below shows the model used in the simulations, while Fig. 3 shows
results of the simulation.
Figure 2 – Model of screen used in simulations
Figure 3 – Simulation Results
ADC Corporation. E-