Design Studies for the Proof-of-Principle of a Gamma Factory

最近提交给欧洲粒子物理战略的一个令人兴奋的新项目是在欧洲核子研究中心建立伽马工厂(GF)的前景，作为Beyond Colliders计划的一部分。GF是一种利用欧洲核子研究中心现有的加速器基础设施来产生超强和高能光子束的新技术。部分剥离的离子束被加速，并与来自强激光光束的光子相互作用，而不是在大型强子对撞机中循环质子。被激发的超相对论离子随后衰变并发射相对论增强的光子，从而产生高度准直、高强度的光子光束，与现有光源相比，具有前所未有的光子能量。这种光子束对无数的研究和应用都很有用，可以从目标上散射，产生极化电子、极化正电子、极化µ子、中微子、中子和放射性离子的次级光束。这些束流为欧洲核子研究中心在基础物理和应用物理的广泛领域提供了各种新的研究机会。欧洲核子研究中心超级质子同步加速器的一项初步原理验证实验正在由62名科学家组成的开创性国际GF合作开发，其中5名科学家在RHUL工作。这里提出的工作，寻求利用RHUL小组创建的软件工具进行初步研究。将开发这些工具，以使用Geant4的扩展，实现无缝模拟部分剥离离子在加速器中的通过、它们与光子的相互作用、激发和随后的衰减的整体方法。我们将应用这些新工具来研究和优化光子-离子相互作用的效率，并确定探测器上的结果分布。在这是一个设计的原则证明实验在欧洲核子研究中心的SPS可以被研究和优化。

An exciting new project recently submitted to the European Strategy for Particle Physics is the prospect of a Gamma Factory (GF) at CERN, as part of the Beyond Colliders Programme. The GF is a new technique to generate ultra-intense and highly energetic beams of photons by making use of the existing accelerator infrastructure CERN. Instead of circulating protons in the LHC, partially-stripped ion beams are accelerated and made to interact with photons from an intense laser beam. The excited ultra-relativistic ions subsequently decay and emit photons that are relativistically boosted and thus generate highly collimated, high-intensity photon beams, with an unprecedented photon energies compared to existing light sources. Such photon beams are useful for myriad studies and applications, and can be scattered from a target to produce secondary beams of polarised electrons, polarised positrons, polarised muons, neutrinos, neutrons and radioactive ions. These beams offer a variety of new research opportunities at CERN in a wide area of fundamental as well as applied physics.An initial Proof-of-Principle experiment at the CERN Super-Proton Synchrotron is being developed by a pioneering international GF collaboration of 62 scientists, 5 of whom are based at RHUL. The work proposed here, seeks to build on initial studies using software tools created by the RHUL group. These tools will be developed to enable a holistic approach to seamlessly simulate the passage of partially-stripped ions in the accelerator, their interaction with the photons, excitation and subsequent decay, using an extension of Geant4. We will apply these new tools to study and optimise the efficiency of the photon-ion interaction and determine the resulting distribution at the detector. In this was the design of a Proof-of-Principle experiment at the CERN SPS can be studied and optimised.