HF PRR – 16 February 20011

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3 Core: 600 ± 10 micron dia Clad: micron dia Buffer: 800 ± 30 micron dia Core material: High OH- sythetic Silica Clad material: Low Index Cladding Polymer Buffer material: Acrylate Core non-circularity: <5% Clad concentricity: ± 3 microns Buffer concentricity: ± 9 microns n clad : nm) 300 nm): <0.15 dB/m 400 nm): <50 dB/km 450 nm): <30 dB/km 850 nm): <20 dB/km NA: 0.33 ± 0.02 Core OH - content: 400 – 1000 ppm (high OH - Fiber) R min curvature (short time)*: 6 cm/1 min R min curvature (long time)*: 10 cm/2 months Quantity: ~1000 km Proof test (100% fibers) : 100 kpsi Operating temp range : - 65 to +125 C * (>98% optical transmission in nm with no memory or breakage) CMS Forward Calorimeter Fiber Specifications

HF PRR – 16 February Optics: HF-QP Specifications Core: 600 ± 10 micron dia Clad: micron dia Buffer: 800 ± 30 micron dia Core material: High OH- sythetic Silica Clad material: Low Index Cladding Polymer Buffer material: Acrylate Core non-circularity: <5% Clad concentricity: ± 3 microns Buffer concentricity: ± 9 microns NA: 0.33 ± 0.02 (Full acceptance cone : 38.5 degrees) n clad : nm) 300 nm): <0.15 dB/m 400 nm): <50 dB/km 450 nm): <30 dB/km 850 nm): <20 dB/km Core OH - content: 400 – 1000 ppm (high OH - Fiber) R min curvature (short time)*: 6 cm/1 min R min curvature (long time)*: 10 cm/2 months Quantity: 850 km Proof test (100% fibers) : 100 kpsi Operating temp range : - 65 to +125 C * (>98% optical transmission in nm with no memory or breakage) Core Clad Buffer

HF PRR – 16 February Update on Fiber Tests - V

HF PRR – 16 February Spectral Measurements

HF PRR – 16 February Photodetector: HF Radiation Environment radiation background simulations show improvement in the design of the shielding around the PMT region by a factor of ~two. There is no issue with the radiation dose or neutron flux where the PMTs are located. The numbers below are quoted per cm2 for 10 years. All neutrons2.54x10 12 Neutr.(E>100KeV)1.63x10 12 Neutr. (E>20 MeV) 5.12x10 11 Ch. Hadrons2.26x10 10 Muons4.65x10 9 Photons1.53x10 12 Dose7 krad

HF PRR – 16 February Optics: Radiation Field Fluence of hadrons (E>100 keV) in cm -2 s -1 (upper plot) and radiation dose in Gy (lower plot) in the HF and its surroundings. The dose plot has been smoothed by taking running averages of the values, which slightly masks the dependence of dose on geometry details. Values are given for 5  10 5 pb -1.

HF PRR – 16 February Red Light? Non-bridging Oxygen Hole Center (NBOHC): (Si-O. ) 1.85 eV (670 nm) emission band remains controversial: This band is reported to have a 4.77 eV (260 nm) absorption band with 1.05 eV half- width. There is another absorption band at 1.97 eV (630 nm). E’-center: (Si. ) The emission band is at 2.75 eV (450 nm) and the absorption band is at 5.86 eV (212 nm). 260 nm NBOHC (1.85 eV) 670 nm (4.77 eV) E E’E’ 212 nm (2.75 eV) 450 nm (5.86 eV) E

HF PRR – 16 February Power-law Behavior ? We can model the effects of radiation on the optical properties of quartz fibers. The model is based on binary molecular kinetics and the rate equations between these two species. The most important feature is that it gives us the prediction power where we can estimate the energy resolution of HF as a function of dose. SilicaColor Center

HF PRR – 16 February Irradiated QP and Attenuation - II The attenuation of QP fibers strongly depend on the accumulated dose. The customary dependence is A(D) = a D b for each wavelength and this is supported by many measurements. This usual behavior is not obvious. It is possible that 240 Mrad data are wrong. Data being analyzed. There is a fair agreement (trend) between the spectrometer data at 425 nm (Xenon) and the PMT data (Co 60 ).

HF PRR – 16 February Cherenkov Light Transmission vs Dose At 100 Mrad for example, 27% of light will be lost at 415 nm. But, there will be wavelength shift to red too.

HF PRR – 16 February Optics: Fiber Radiation Damage and Induced Resolution - I Quartz fiber irradiation studies were carried out in the last several years. The induced attenuation profile shows that there is less absorbtion in nm (PMT) region compared to either shorter or longer wavelengths. 54 Mrad QP

HF PRR – 16 February Optics: QQ/QP Comparison for Radiation Hardness - II The purity of the core material is paramount for radiation hardness of the fiber. In one case (left plot), the core is obtained from Heraeus and on the other case (right plot), from a less-known supplier of preforms. 450 nm 610 nm Total = 2.06 x e- = 80 MRad 1.60 x e- = 64 MRad  = [I (QP)] / [I (QQ)]  = [I (QQ)] / [I (QP)] 450 nm 610 nm

HF PRR – 16 February

HF PRR – 16 February

HF PRR – 16 February

HF PRR – 16 February

HF PRR – 16 February IetadD/dt [rad/s] a (95% Conf. Bounds) [dB/m] b (95% Conf. Bounds) x (-1.36, 4.12)0.39 (0.21, 0.58) x (-0.46, 9.93)0.59 (0.47, 0.72) x (0.40, 4.45)0.72 (0.58, 0.86) x (0.75, 1.82)0.79 (0.68, 0.91)

HF PRR – 16 February

HF PRR – 16 February