1. Design optimization of Fiber readout system
Institute of High Energy Physics, CAS

2. Requirements on Fiber readout system
Requirements on HERD prototype
DR ~ 6000
Frame rate ~ 500 fps (320 fps)
Requirements on HERD CALO
DR ~ 3e6 (1/ MIP), two ranges
1 MIP = p.e.
1e4 - 1e8 p.e. for high range
Frame rate ~ 500 fps
Working mode: trigger mode

3. Design optimization SCMOS instead of CCD Faster frame rate
Global shutter; ROI readout
Lower noise

4. Parameters comparison
Diameter of front taper should be less than 150 mm;
Taper ratio should be less than 3:1;
FOUR sets of ISCMOS is needed for HERD CALO.
SCMOS pixel size (um)
5.5
Distance between fibers (mm) 1
Number of pixels for 1 fiber (1d) 20
Taper ratio (overall)
9.09
Number of occupied pixels for one SCMOS
2304
648
3456
4608
ROI (mm)
12.672
3.564
19.008
25.344
Available number of fibers for one SCMOS
3732
5599
7465
Aspect ratio of ROI
3.56
5.33
7.11
Diameter of II (mm) 75 40
Dimension of Inscribed rectangle of II (mm)
72.20
20.31
38.51
10.83
73.72
13.82
39.31
7.37
74.27
10.44
39.61
5.57
Taper ratio (rear)
5.70
3.04
3.88
2.07
2.93
1.56
Distance between fibers on II (um)
627
334
427
228
322
172
Taper ratio (front)
1.60
2.99
2.34
4.40
3.10
5.82
Diameter of front taper
120
176
233
Number of ISCMOS system for one range 2

5. Image intensifier For high range ISCMOS For low range ISCMOS
Magnetic focus I.I.
Very high linear dynamic range (~1e5)
Low gain (~200)
Little diffusion (crosstalk)
For low range ISCMOS
MCP I.I.
Reliability of I.I. in trigger mode
Update of HERD prototype based on optimized design is ongoing.