Estimation and Protection on Synchrotron Radiation in CEPC Main Ring Shi Haoyu, Ding Yadong, Ma Zhongjian IHEP,CAS 1st CEPC SRS Workshop

Shi Haoyu -- CEPC SRS Workshop Outline Harm of Synchrotron Radiation Parameters of Synchrotron Radiation in CEPC Simulation Shielding Design for Magnets Effects of the Shielding Future Work 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shi Haoyu -- CEPC SRS Workshop Outline Harm of Synchrotron Radiation Parameters of Synchrotron Radiation in CEPC Simulation Shielding Design for Magnets Effects of the Shielding Future Work 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Harm of Synchrotron Radiation Synchrotron radiation will induce: Heating of the vacuum chamber Radiation damage to machine elements Formation of ozone and nitrogen oxides in the air Leading to corrosion of machine components and health hazards for personnel Radioactivity induced in components Other issues…… 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Harm of Synchrotron Radiation Direct: Radiation Damage Heat Deposition Indirect: Radioactivity Noxious Gas And so on 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shi Haoyu -- CEPC SRS Workshop Outline Harm of Synchrotron Radiation Parameters of Synchrotron Radiation in CEPC Simulation Shielding Design for Magnets Effects of the Shielding Future Work 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shi Haoyu -- CEPC SRS Workshop Parameters of SR Direction of Deflection Dipole Only consider SR produced in Dipole Magnet SR produced in Quadrupole and Sextupole(except FFS) can be ignored SR in Injection and Extraction Magnet will study in the future 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shi Haoyu -- CEPC SRS Workshop Parameters of SR Energy spectrum distribution: Angular distribution: Formulas listed in Appendix 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shi Haoyu -- CEPC SRS Workshop Parameters of SR 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shi Haoyu -- CEPC SRS Workshop Parameters of SR Parameters Symbols Units Values Beam energy E GeV 45.5 80 120 Beam current I mA 83.8 90.3 17.7 Bending radius ρ m 10900 Power per unit length P W/m 42.62 438 435 Critical energy Ec keV 19.01 103.3 348.8 Bending angle θ mrad 2.844 Opening angle φ μrad 11.23 6.387 4.258 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shi Haoyu -- CEPC SRS Workshop Outline Harm of Synchrotron Radiation Parameters of Synchrotron Radiation in CEPC Simulation Shielding Design for Magnets Effects of the Shielding Future Work 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shi Haoyu -- CEPC SRS Workshop Simulation Tool: FLUKA, checked with MCNP Source : Photon, not electron/positron 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Simulation Assumption Energy: Lowest 1 keV Highest 6 MeV Gap 1keV Written in Python Number: 𝑁 𝑝ℎ𝑜𝑡𝑜𝑛 = 𝑃 𝐸 𝑎𝑣𝑒 ∙𝑡 2.363×1016m-1s-1 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Simulation Assumption Position: Opening Angel ignored Take the orbit of beam as straight line Direction: X-Z Plane Left or Right 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shi Haoyu -- CEPC SRS Workshop Outline Harm of Synchrotron Radiation Parameters of Synchrotron Radiation in CEPC Simulation Shielding Design for Magnets Effects of the Shielding Future Work 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

The Safety of Coils in Dipole LEP Spring-8 Materials Upper dose limit in Gy Fiberglass 108 Semi-organic coating Epoxy resin 2×107 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shielding Design - Dipole 2 cm Lead 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shielding Design - Quadrupole 2 cm Lead 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shielding Design - Sextupole 2 cm Lead 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shielding Design – Vacuum Chamber 2 cm Lead 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shi Haoyu -- CEPC SRS Workshop Outline Harm of Synchrotron Radiation Parameters of Synchrotron Radiation in CEPC Simulation Shielding Design for Magnets Effects of the Shielding Future Work 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Effects – Dose in Dipole Without Shield With Shield Without Shield With Shield Max Dose 5.11E5 Gy/Ah 1.89E4 Gy/Ah Coil Life-time 2211.24 h 59875.37 h 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Effects – Heat in Dipole Total power 870 W/m Beam direction: left W/m Beam direction: right W/m Al chamber  199 186  Cu chamber  308 332 Dipole  186 182 Lead A  60.6 29.2  Lead B  33.5 80.0  Lead C  46.8 18.8  Lead D 14.3 20.4  2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Effects – Heat in Dipole Total power 870 W/m Without Shield With Shield Al Chamber 199 Al chamber  199 Cu Chamber 310 Cu chamber  308 Dipole 255  186 - Lead  155.2 Air 106 21.8 Total Bending Length: ~68,452 m 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Effects – Heat in Dipole Total power 59.6 MW/turn Without Shield With Shield Al Chamber 13.6 Al chamber Cu Chamber 21.2 Cu chamber  21.1 Dipole 17.5  12.7 - Lead  10.6 Air 7.3 1.49 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Effects – Dose in Quadrupole Without Shield With Shield Without Shield With Shield Max Dose 4.69E5 Gy/Ah 0.82E4 Gy/Ah Coil Life-time 2409.26 h 1.37E5 h 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Effects – Heat in Quadrupole Total power 870 W/m Beam direction: left W/m Beam direction: right W/m Quadrupole  279 268 Lead A  37.8 36.4  Lead B  18.1 21.7  2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Effects – Dose in Sextupole With Shield Without Shield Without Shield With Shield Max Dose 3.25E6 Gy/Ah 1.67E4 Gy/Ah Coil Life-time 347.67h 67661.29 h 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Effects – Heat in Sextupole Total power 870 W/m Beam direction: left W/m Beam direction: right W/m Sextupole  179 174 Lead A  95.1 107  Lead B  60.3 43.1  2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Effects – Dose in Magnets Dose in Gy/Ah with/out Shield in Magnets Magnets Dipole Quadrupole Sextupole Without Shield 5.11E5 Gy/Ah 4.69E5 Gy/Ah 3.25E6 Gy/Ah With Shield 1.89E4 Gy/Ah 0.82E4 Gy/Ah 1.67E4 Gy/Ah Coil Life-time with/out Shield in Magnets (44000h/yr) Magnets Coil Life-time Without Pb Coil Life-time With Pb Dipole 0.5 yr 13.59 yr > 10 yr Quadrupole 0.54 yr 31.32 yr Sextupole 0.08 yr 15.38 yr 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Dose Distribution in Tunnel without Shield Gy/Ah 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shi Haoyu -- CEPC SRS Workshop Outline Harm of Synchrotron Radiation Parameters of Synchrotron Radiation in CEPC Simulation Shielding Design for Magnets Effects of the Shielding Future Work 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Thanks for your attention Future Work The Extraction of the SR The Simulation of SR in other magnets The Improvement of simulation Thanks for your attention 2018/11/15 Shi Haoyu -- CEPC SRS Workshop

Shi Haoyu -- CEPC SRS Workshop Appendix SR critical energy： Solid degree 𝜑 ： 𝐸 𝑐 𝑘𝑒𝑉 =2.2 𝐸(𝐺𝑒𝑉) 3 𝜌(𝑚) 𝜑= 1 𝛾 = 𝑚 0 𝑐 2 𝐸 = 1 1957 𝐸 𝑒 (𝐺𝑒𝑉) ~ 351.6 keV SR Power： Number of photons (Method 1)： 𝑃 𝑊 𝑚 =14.1 𝐸 𝐺𝑒𝑉 4 𝐼(𝑚𝐴) 𝜌(𝑚) 2 𝑁 𝑝ℎ𝑜𝑡𝑜𝑛 = 𝑃 𝐸 𝑎𝑣𝑒 ∙𝑡 ~ 435 W/m Number of photons (Method 2)： SR spectrum： 𝑑𝑁 𝑑𝑠 = 0 ∞ 𝐸 𝑐 𝑑 2 𝑁 𝑑𝜀𝑑𝑠 𝑑𝑟= 3.936 𝐸 𝜌 0 ∞ 𝑟 ∞ 𝐾 5 3 𝜂 𝑑𝜂𝑑𝑟=19.4 𝐸 𝜌 𝑆 𝜔 = 9 3 8𝜋 𝜔 ∞ 𝐾 5 3 (𝜂)𝑑𝜂 𝜔= 𝜔 𝐸 𝜔 𝑐 2018/11/15 Shi Haoyu -- CEPC SRS Workshop