1. HF QUARTZ FIBER
Y.Onel , J.P.Merlo, K.Cankocak, I.Dumanoglu, I.Schmidt and A.Penzo

2. Quartz Radiation Damage Studies
Electron Irradiation Tests:
Dumanoglu et al. “Radiation-hardness studies of high OH content quartz fibres irradiated with 500 MeV electrons” Nucl. Instr. Meth. A 490 (2002)
Proton Irradiation Tests:
Cankocak et al. “Radiation-hardness measurements of high OH content quartz fibres irradiated with 24 GeV protons up to 1.25 Grad“ Nucl. Instr. and Meth. A 585 (2008) 20–27
Neutron and Gamma Irradiation Tests:
U. Akgun et al. “Radiation Damage in Quartz Fibers
Exposed to Energetic Neutrons”
Submitted to IEEE Transactions on Nuclear Science.

3. Expected HF Fiber Exposure and Scenario
Luminosity
Ring 1-5
Ring 6-9
Ring 10-13
LHC (at 1034)
1 Mrad/year
10 Mrad/year
100 Mrad/year
Phase I (1.5 *1034)
1.5 Mrad/year
15 Mrad/year
150 Mrad/year
Phase II (3 *1034)
3 Mrad/year
30 Mrad/year
300 Mrad/year
SLHC (1035)
1 Grad/year
These numbers are without recovery of fibers. We expect the fiber to recover at least 20% at each shutdown.
QP Fibers can survive at 1 Grad at high eta.
The PMTs have sensitivity range nicely fitting with Fiber “sweet range” of 380 nm-580 nm).
PMT HV adjustment can easily make up for lost light intensity due to radiation.

4. Estimate of radiation damage and recovery versus dose in HF quartz fibers
tirr (days) 1 2 3 5 10 20 50
100
150
200
2000
Dose
(Mrad)
0.5
1.0
1.5
2.5
5.0 25 75
1000
A (dB/m)
0.156
0.211
0.252
0.316
0.428
0.581
0.869
1.179
1.410
1.600
2.754
Signal
loss (%)
5.7
7.7
9.1
11.3
15.0
19.8
28.0
36.1
41.5
45.6
65.0
Increase
aft.1h (%)
1.7
1.9
2.1
2.3
2.7
3.0
3.6
4.0
4.3
4.5
4.1
aft.8h (%)
3.3
3.8
4.4
5.1
6.2
7.1
8.1
7.4
aft.1d (%)
3.7
4.7
5.6
6.6
9.0
9.8
10.9
10.2
af.10d(%)
5.8
6.8
8.5
10.4
13.4
16.1
17.9
19.2
19.4

5. Assembly of Raddam fibres
spacer
To PMT
Raddam fiber
From laser
Assembly tool

6. HF Towers raddam equipped
(A) Wedges towers EM2 HAD4 EM6 HAD8 EM10 HAD12 EM13
(B) Wedges towers HAD2 EM4 HAD6 EM8 HAD10 EM HAD13
Within in a wedge 7 towers are instrumented with these sample fibers. In total there are 56 sample fibers in the entire system which will provide radiation damage information [1].

7. SUMMARY
The RADDAM system has been tested with LHC-HCAL DAQ installed at the CMS experiment. The RADDAM on-line system and the quart fiber irradiations at LIL, PS and ANL including all equipment were funded IOWA VP of reseach.
QP fiber will survive up to 1 Grad and more(10 years of LHC running at 10**34). QQ fibers will last longer and rings10-13 High Eta Towers—eta )
The results of irradiation of one fiber in a PS beam at high dose rate (2.6 Mrad/hour) with HCAL-DAQ read out agreed with previous transmission measurements[1][2].
The source calibration results done at a post data taking time t > 1h have to be corrected to reduce systematic error.
With the increase of dose (0.5 Mrad/day at full luminosity near  = 5) the raddam device monitors the light signal losses near 450 nm and estimate the correction to apply to source calibration results. Nucl. Instr. Meth. A 490 (2002) , Nucl. Instr. and Meth. A 585 (2008) 20–27.