A low-energy medium-luminosity Muon Collider (MC) is being studied as a possible Higgs Factory (HF). Electrons from muon decays will deposit more than 300 kW in superconducting magnets of the HF collider ring. This imposes significant challenges to superconducting (SC) magnets used in the MC storage ring (SR) and interaction regions (IR). Magnet designs are proposed which provide high operating gradient and magnetic field in a large aperture to accommodate the large size of muon beams (due to low beta*), as well as a cooling system to intercept the large heat deposition from the showers induced by decay electrons. The distribution of heat deposition in the MC SR lattice elements requires large-aperture magnets in order to accommodate thick high-Z absorbers to protect the SC coils. Based on the developed MARS15 model and intensive simulations, a sophisticated radiation protection system was designed for the collider SR and IR to bring the peak power density in the superconducting coils below the quench limit and reduce the dynamic heat deposition in the cold mass by a factor of 100. The system consists of tight tungsten masks in the magnet interconnect regions and elliptical tungsten liners in the magnet aperture optimized individually for each magnet. These also reduce the background particle fluxes in the collider detector.
Low-energy medium-luminosity Muon Collider (MC) is being studied as a possible Higgs Factory (HF). Electrons from muon decays will deposit more than 300 kW in superconducting magnets of the HF collider ring. This imposes significant challenges to superconducting (SC) magnets used in the MC storage ring (SR) and interaction regions (IR). The magnet designs are proposed which provide high operating gradient and magnetic field in a large aperture to accommodate the large size of muon beams due to low \b{eta}* as well as the cooling system to intercept the large heat deposition from the showers in…
Reducing backgrounds in the higgs factory muon collider detector
125 GeV希格斯工厂（HF）μ子对撞机（MC）的初步设计已经确定了HF探测器上巨大的本底载荷。这与12倍更高的μ介子衰变概率在HF相比，以前研究的1.5 TeV MC。作为MARS 15优化研究的结果，它表明，与精心设计的保护系统中的相互作用区域，在机器探测器接口和探测器内，可以减少背景率到一个可管理的水平，类似于实现优化的1.5-TeV的情况下。HF探测器背景的主要特点，提出的配置发现。
A neutrino factory or muon collider requires the capture and cooling of a large number of muons. Scenarios for capture, bunching, phase-energy rotation and initial cooling of μ's produced from a proton source target have been developed, initially for neutrino factory scenarios. They require a drift section from the target, a bunching section and a ϕ-δE rotation section leading into the cooling channel. Important concerns are rf limitations within the focusing magnetic fields and large losses in the transport. The currently preferred cooling channel design is an "HFOFO Snake" configuration that…
Radiation effects in a muon collider ring and dipole magnet protection
μ子对撞机储存环（MCSR）的要求和运行条件对超导磁体提出了重大挑战。偶极磁体应该提供高磁场以减小环周长，从而在其寿命期间最大化μ子碰撞的数量。对于1.5 TeV c.o.m.，三分之一的束能量通过衰变电子以0.5 kW/m的速率沿着晶格连续沉积。光度为1034 cm-2s-1。与质子机中的偶极子不同，MCSR偶极子应该允许这种动态热负荷在水平面中逸出磁体氦体积，主要朝向环中心。本文分析和比较了两种偶极磁体设计的MCSR中的辐射效应。在这两种情况下，互连区域中的钨掩模用于减轻磁体线圈中前所未有的动态热沉积和辐射。
A Muon Collider poses a number of challenging problems in the lattice design - low beta-star, small circumference, large physical and dynamic aperture - which must be solved in order to realize the unique opportunities it offers for the high-energy physics. This contribution presents basic solutions which make it possible to achieve the goals for both the energy frontier collider and the Higgs factory with Nb3Sn magnet parameters.
This White Paper brings together our previous studies on a Muon Collider (MC) and presents a design concept of the 6 TeV MC optics, the superconducting (SC) magnets, and a preliminary analysis of the protection system to reduce magnet radiation loads as well as particle backgrounds in the detector. The SC magnets and detector protection considerations impose strict limitations on the lattice choice, hence the design of the collider optics, magnets and Machine Detector Interface (MDI) are closely intertwined. As a first approximation we use the Interaction Region (IR) design with beta-star=3 mm…
An energy of $362\:\text{MJ}$ is stored in each of the two LHC proton beams for nominal beam parameters. This will be further increased to about $700\:\text{MJ}$ in the future High Luminosity LHC (HL-LHC) and uncontrolled beam losses represent a significant hazard for the integrity and safe operation of the machine. In this paper, a number of failure mechanisms that can lead to a fast increase of beam losses are analyzed. Most critical are failures in the magnet protection system, namely the quench heaters and a novel protection system called Coupling-Loss Induced Quench (CLIQ). An important o…
The Gersemi cryogenic test bench, installed at FREIA laboratory at Uppsala University, was used for the first time in 2021 to power a superconducting magnet. As part of the HL-LHC program, this cryostat offers an operating temperature between 4.2K and 1.9K. Its satellite equipment such as power converters and the acquisition system allow two superconducting magnet coils to be powered up to 2 kA and provide magnet protection through a robust quench detection and two energy extraction units. This report describes Gersemi's first cryogenic operational experiment and the safety strategy to ensure …
Coupling of Magneto-Thermal and Mechanical Superconducting Magnet Models by Means of Mesh-Based Interpolation
CERN（欧洲核子研究组织）；Institute of Automatic Control, Technical University of Łódź（罗兹理工大学自动控制研究所）；Fraunhofer Institute SCAI（弗劳恩霍夫SCAI研究所）；Paul Scherrer Institute（保罗谢尔研究所）；Technische Universität Darmstadt（达姆施塔特工业大学）；RWTH Aachen（亚琛工业大学）
