Lepton Collider R&D

根据可靠的实验证据，电子、正电子和μ子都是基本的、基本的粒子，没有任何成分。这与（重得多的）质子不同，例如，质子由夸克和胶子组成。 因此，在实验室中使用这些基本粒子与那些动量相等和相反的粒子碰撞，为创造具有明确定义的能量和运动学的新形式的物质提供了完整的质心能量。由于这个原因，粒子物理学家的研究呼吁对加速器科学和技术进行大量投资，这些科学和技术可能导致具有TeV（Tera [10的12次方]）电子投票）规模质心能量的轻子对撞机，以及现有的质子对撞机，如大型强子对撞机（LHC）。 该项目涵盖了这种轻子对撞机的几个关键加速器科学和技术组件的研发;然而，其结果将适用于世界各地许多现有和未来的各种加速器。将开展的研究领域直接支持这些国家优先事项。世界各地的主要实验室目前正在进行加速器的研究和开发，这将导致能够达到这一能量范围的线性电子-正电子对撞机的详细设计。为此目的开发的技术也将通过新一代的强光源应用于其他科学和技术领域。请注意，加速器有两种基本形状。直线加速器（linacs）是沿着直线路径加速基本粒子，而环形加速器，如Tevatron和大型强子对撞机（LHC），则使用环形路径。圆形几何结构在能量高达数十GeV（10的9次方电子伏）时具有显着的优势：通过圆形设计，粒子可以有效地加速更长的距离。此外，只有一小部分粒子被带到碰撞过程中实际发生碰撞。在线性加速器中，剩余的粒子会丢失;在环形加速器中，它们会继续循环，并可用于未来的碰撞。圆形加速器的缺点是粒子在沿着弯曲的路径运动时必然会发射出电磁辐射，即同步辐射。通过同步辐射的能量损失与所讨论的粒子质量的四次方成反比。轻子是轻的，以这种方式失去大量的能量。这就是为什么建造用于重粒子的环形加速器--强子对撞机，如用于质子的大型强子对撞机--是有意义的。同样大小的正负电子对撞机永远无法达到同样的碰撞能量。事实上，LEP轻子对撞机的能量被限制在209 GeV，因为同步辐射的能量损失。由于之前的资助，康奈尔加速器现在是一个灵活的，世界上独一无二的测试加速器实验室，让一群科学家和工程师（与全球合作伙伴）测试和解决当今最先进的加速器所面临的一些最具挑战性的问题。这些世界范围内的合作和实验室之间的共同努力，如康奈尔大学及其扩展的同事和合作伙伴之间的合作，以及康奈尔大学对社区的推广，被社区视为典范。

Electrons, positrons and muons are, based on solid experimental evidence, fundamental, elementary particles with no components. This is unlike the (much heavier) proton, for example, which is composed of quarks and gluons. Thus using these fundamental particles in collisions with those of equal and opposite momenta in the laboratory provides the full center of mass energy for creation of new forms of matter with well defined energy and kinematics. For this reason studies by particle physicists have called for significant investment in the enabling accelerator science and technologies that might lead to lepton colliders with TeV (Tera [10 to the power 12 ] ) electron votes) scale center of mass energies, in addition to existing proton colliders such as the Large Hadron Collider (LHC). This project covers R&D in several of the key accelerator science and technology components of such a lepton collider; however, the results will be applicable to many existing and future accelerators of all kinds around the world. The research areas that will be pursued directly support these national priorities. Major laboratories around the world are presently conducting accelerator research and development that will lead to detailed designs of a linear electron-positron collider capable of reaching this energy range. The technology being developed for this purpose will also have applications to other areas of science and technology through new generations of intense light sources. Note that there are two basic shapes of accelerators. Linear accelerators ("linacs") accelerate elementary particles along a straight path. Circular accelerators, such as the Tevatron and the Large Hadron Collider (LHC), use circular paths. Circular geometry has significant advantages at energies up to and including tens of GeV (10 to the power 9 electron volts) : With a circular design, particles can be effectively accelerated over longer distances. Also, only a fraction of the particles brought onto a collision course actually collide. In a linear accelerator, the remaining particles are lost; in a ring accelerator, they keep circulating and are available for future collisions. The disadvantage of circular accelerators is that particles moving along bent paths will necessarily emit electromagnetic radiation known as synchrotron radiation. Energy loss through synchrotron radiation is inversely proportional to the fourth power of the mass of the particles in question. Leptons, being light, lose a large amount of energy in this way. That is why it makes sense to build circular accelerators for heavy particles - hadron colliders such as the LHC for protons. An electron-positron collider of the same size would never be able to achieve the same collision energies. In fact, energies at the LEP lepton collider, which used to occupy the tunnel now given over to the LHC, were limited to 209 GeV by energy loss via synchrotron radiation.As a result of previous funding the Cornell accelerator is now a flexible, unique-in-the-world test accelerator laboratory, allowing a group of scientists and engineers (with worldwide partnerships) to test and solve some of the most challenging problems faced by state-of-the-art accelerators today. These worldwide collaborations and joint efforts between labs such as those between Cornell and its extended group of colleagues and partners, and Cornell's outreach to the community, are viewed as exemplary by the community.