“Chung-Yao Chao Fellowship” Application Ye Zou(邹野) IHEP CEPC-SPPC 合作组

Resume 2005.09 ~ 2009.06 中国科学技术大学 近代物理系 粒子物理与核物理专业 学士 2005.09 ~ 2009.06 中国科学技术大学 近代物理系 粒子物理与核物理专业 学士 2009.09 ~ 2015.03 中科大国家同步辐射实验室与高能所联合培养硕博连读研究生（2010.08 ~ 2015.03 在高能所完成博士课题） 博士 导师：唐靖宇 2015.03 ~ 今 高能物理研究所 博士后 合作导师：唐靖宇

Previous work and achievements Studies on new extraction methods from proton synchrotrons (to satisfy the requirements of new beam application) Parasitic slow extraction of extremely weak beam from a high-intensity proton rapid cycling synchrotron Studies on short-bunch extraction at CSNS/RCS Resonant slow extraction in synchrotrons by using anti-symmetric sextupole fields Studies on collimation system (to satisfy the requirements of high-intensity synchrotron and collider) 强调（简明）这些课题研究工作的价值和目的，如引出研究是束流应用对束流品质提出了越来越高的要求，需要发展新的方法或改进原有的方法；束流准直方法研究是为了适应高功率质子同步加速器和超级质子对撞机发展的需求（以前研究较小）。 Combined momentum collimation studies in a high-intensity rapid cycling proton synchrotron Preliminary design of SPPC collimation system

Parasitic slow extraction of extremely weak beam from a high-intensity proton rapid cycling synchrotron CSNS/RCS Parasitic slow extraction For detector tests and studies on space radiation effects, extremely weak beam is needed First time using scattering foil for slow extraction First time generating additional orbit bump by momentum deviation Extraction rate: 10 protons per turn or about 6× 10 5 per second Results were published in Nucl. Instr. and Meth., A

Studies on short-bunch extraction at CSNS/RCS White neutron source is needed for nuclear data measurements and short-bunch proton beams from synchrotron is helpful for improving the time resolutions of neutrons First time using bunch rotation method in rapid cycling synchrotron First time using static compression method to keep beam without acceleration Results: rms bunch length is reduced to 1/9 and the time resolutions is significantly improved by an order of magnitude with energy higher than MeV, which were published in Phys. Rev. ST-AB

Resonant slow extraction in synchrotrons by using anti-symmetric sextupole fields A new method for resonant slow extraction Anti-symmetric sextupole field 𝑩 𝒙 = 𝒅 𝟐 𝑩 𝒚 𝒅 𝒙 𝟐 𝟎 𝒙 𝒚 , 𝑩 𝒚 = 𝟏 𝟐 𝒅 𝟐 𝑩 𝒚 𝒅 𝒙 𝟐 𝟎 𝒙 𝟐 − 𝒚 𝟐 𝒙 𝒙 Using special anti-symmetric sextupole field at second-order resonance More distant tune from the resonance Smaller and flatter stable region with the same tune distance and field strength Less sensitivity to the tune variation due to the ripple of power supplies Less phase-space distortion from a normal beam Results have been submitted to Phys. Rev. ST-AB

C-S invariant (mm.mrad) Combined momentum collimation studies in a high-intensity rapid cycling proton synchrotron A new momentum collimation method for CSNS/RCS C-S invariant (mm.mrad) /off- momentum Anti-correlated Correlated Collim. efficiency Turns Ix =333, = 1.03% 98.4% 80 61.9% 70 Ix =333, = -1.03% 94.1% 250 58.8% 130 Ix =18, = -1.85% 94.3% 96.2% 100 There is no momentum collimation scheme that has especially high efficiency at compact high-intensity synchrotron A combined momentum collimation scheme is studied: combining two separate two-stage collimation systems and a single-stage collimation system The collimation efficiency can achieve more than 90% which is very high for compact RCS Results were published in Phys. Rev. ST-AB This is the foundation for SPPC collimation

Publication list [1] Y. Zou, J.Y. Tang, Z. Yang, H.T. Jing, “Parasitic slow extraction of extremely weak beam from a high-intensity proton rapid cycling synchrotron”, Nucl. Instr. and Meth., A 737 (2014) 56-64 [2] Y. Zou, J.Y. Tang, J.F. Chen, X. Li, H. Sun, “Short-bunch extraction in a rapid cycling synchrotron”, Phys. Rev. ST-AB, 17,060101 (2014) [3] J.Y. Tang, J.F. Chen, Y. Zou, “Combined momentum collimation studies in a high-intensity rapid cycling proton synchrotron”, Phys. Rev. ST-AB, 14, 050103 (2011) [4] CEPC-SPPC Preliminary Conceptual Design Report, Volume II –Accelerator, one of the authors Y. Zou, J.Y. Tang, J.Q. Yang “Resonant Slow Extraction in Synchrotrons by Using Anti-symmetric Sextupole Fields”, which has been submitted to Phys. Rev. ST-AB Report of Referee A -- ZB10087/Zou This paper has proposed a half integer resonant slow extraction driven by an anti-symmetric sextupole field. This ideal using an anti-symmetric sextuple field is new and has a merit less sensitive to tune ripple than an ordinary third integer slow extraction. The idea has been examined analytically and numerically and clearly described in this paper. Authors is expected to respond to the following comments or questions to clarify contents in the paper… Report of Referee B -- ZB10087/Zou The topic is interesting and deserves publication, but the paper cannot be published in its present form. The main limitations I encountered are…

Conference list [1] Y. Zou, J.Y. Tang, Z. Yang, H.T. Jing, C. Meng, “Parasitic slow extraction of extremely weak beam from a high-intensity proton rapid cycling synchrotron”, Proceedings of IPAC13, Shanghai, China (2013), p. 1931 [2] Y. Zou, J.Y. Tang, J.F. Chen, “Studies on Short-Bunch Extraction at CSNS RCS”, Proceedings of NA-PAC13, Pasadena, California, USA (2013), p. 297 [3] Y. Zou, J.Y. Tang, “Resonant Slow Extraction in Synchrotrons by Using Anti-symmetric Sextupole Fields”, Proceedings of IPAC14, Dresden, Germany (2014), p. 827 [4] J.Y. Tang, J.F. Chen, Ye Zou, IHEP, Beijing 100049, China, “Momentum Collimation in a High-intensity Compact Rapid Cycling Proton Synchrotron” Proceedings of HB2010, Morschach, Switzerland, p. 254 [5] J.F. Chen, J.Y. Tang, Ye Zou, “Combined Momentum Collimation method in High-intensity Rapid Cycling Proton Synchrotrons”, Proceedings of IPAC2011, San Sebastián, Spain, p. 2736 [6] H.P. Jiang, Y. Zou, S.N. Fu, C. Meng, “Beam Dynamics Analysis in the Beam Halo Experiments at IHEP”, Proceedings of IPAC14, Dresden, Germany (2014), p. 3159

Working plan: SPPC collimation system design 束流准直是SPPC中极为重要的系统，它关系到SPPC能否安全和可靠地运行。LHC设计有两个长直线段分别。。。；FCC甚至设计了2个2.8km长的空间安排准直系统，CEPC-SPPC设计目前最为紧急的任务就是确定SPPC准直系统需要的长直线段空间，它关系到CEPC隧道的布局和Lattice设计，我们将争取在近期内回答这个问题。 More than 100 movable collimators Collimation is one of the critical issues for the success of SPPC

SPPC VS LHC/FCC FCC SPPC Factor~18 HL-LHC LHC 2012 𝜂= 𝑁 𝑙𝑜𝑠𝑡 Δ𝑠∙ 𝑁 𝑎𝑏𝑠 Cleaning inefficiency: 𝜂= 𝑁 𝑙𝑜𝑠𝑡 Δ𝑠∙ 𝑁 𝑎𝑏𝑠 Cleaning inefficiency for LHC 𝟏𝟎 −𝟓

SPPC VS LHC/FCC LHC (design) HL-LHC FCC-hh SPPC Beam energy 7 TeV Beam intensity 3×10 14 6×10 14 1×10 15 1.2×10 15 Stored energy 360 MJ 690 MJ 8500 MJ 6600 MJ Power load ( τ=0.2h) ~500 kW ~960 kW ~11800 kW ~9200 kW Factor 18  LHC: Higher cleaning efficiency to avoid quenches! Required cleaning inefficiency at least: 10 −6 More collimators and optimization of collimation method are needed

SPPC multi-stage collimation system From CEPC-SPPC Pre-CDR Five-stage collimation method is considered for both betatron collimation and momentum collimation Collimators determine the SPPC impedance: more stages, larger impedance The β* reach is also determined by collimation constraints

下一步计划 研究计划 1. 在1至2个月内给出SPPC准直系统需要的长直线段空间 2. 在一年内为SPPC设计一套多级准直系统方案 3. 进一步研究采用非线性力的方法进行准直系统的研究 博士后期间计划发表2至3篇期刊文章

Thanks! 非常感谢CEPC-SPPC合作组