Unveiling the Physics of High-Density Relativistic Pair Plasma Jets in the Laboratory

在实验室中揭示高密度相对论对等离子体射流的物理原理

• 批准号: EP/Y035038/1
• 负责人: Gianluca Gregori
• 金额: $ 269.73万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FY035038%2F1
• 关键词: Unveiling; Physics; Density; Relativistic; Pair

Gamma-ray bursts (GRBs) are among the most energetic events in the Universe. They occur at cosmological distances and are the result of the collapse of massive stars or neutron stars mergers, with emission of relativistic 'fireballs' of electron-positron pairs. From astrophysical observations, a wealth of information has been gleaned about the mechanism that leads to such strong emission of radiation, with leading models predicting that this is due to the disruption of the beam as it blasts through the surrounding plasma. This produces shocks and hydromagnetic turbulence that generate synchrotron emission, potentially accelerating to ultra-high energies the protons which are observedon Earth as cosmic rays. However, there is no direct evidence of the generation of either magnetic fields or cosmic rays by GRBs. Estimates are often based on crude energy equipartition arguments or idealized numerical simulations that struggle to capture the extreme plasma conditions. We propose to address this lacuna by conducting laboratory experiments at CERN to mimic the jet propagation through its surrounding plasma. Such experiments will enable in situ measurement of the plasma properties, with exquisite details that cannot be achieved elsewhere. The experiments also complement numerical simulations by providing long measurement times extending into the non-linear regime where numerical simulations are not possible today. The proposed experiments will study fundamental physics processes, unveil the microphysics of GRBs, and address the following, yet answered, key questions:1) What mechanisms drive the energetic beams unstable and their long-term evolution?2) What is the role of turbulence in the acceleration of particles to the highest energies?3) What is the interplay between magnetic fields and particles and how does this affect the observedelectromagnetic emission?We will provide a new window in high energy astrophysics using novel Earth-based laboratory experiments.

伽马射线暴（GRB）是宇宙中最具能量的事件之一。它们发生在宇宙学距离上，是大质量恒星坍缩或中子星合并的结果，伴随着电子-正电子对的相对论性“火球”的发射。从天体物理学的观测中，已经收集到了大量关于导致如此强烈的辐射发射的机制的信息，主要模型预测这是由于光束在穿过周围等离子体时的破坏。这会产生冲击波和磁流体湍流，产生同步辐射，可能会将地球上以宇宙射线形式存在的质子加速到超高能量。然而，没有直接证据表明伽玛暴产生磁场或宇宙射线。估计通常是基于粗略的能量均分参数或理想化的数值模拟，难以捕捉极端的等离子体条件。我们建议通过在CERN进行实验室实验来模拟射流通过周围等离子体的传播来解决这个问题。这样的实验将使现场测量等离子体的性质，与精致的细节，不能在其他地方实现。实验还补充了数值模拟，提供了长的测量时间延伸到非线性制度，其中数值模拟是不可能的今天。拟议的实验将研究基本的物理过程，揭示伽玛暴的微观物理，并解决以下尚未回答的关键问题：1）是什么机制驱动高能光束不稳定及其长期演化？2)在粒子加速到最高能量的过程中，湍流的作用是什么？3)磁场和粒子之间的相互作用是什么？这又是如何影响电磁辐射的？我们将利用新颖的地球实验室实验为高能天体物理学提供一个新的窗口。