MRI: Acquisition of a Helium Ion Source Upgrade for the Edwards Accelerator Laboratory at Ohio University

原子核的强流对于基础研究和应用研究是必不可少的。这些离子束可以用来再现和研究恒星中发生的核反应和恒星爆炸，表征对核能和国家安全感兴趣的核反应，并通过离子束分析帮助开发新材料。这类实验是在俄亥俄大学爱德华兹加速器实验室(EAL)进行的，由于氦引发的核反应在性质和应用中无处不在，因此氦原子核扮演着特别重要的角色。该合同提供资金用于升级EAL的氦离子源，这将大大提高运行的可靠性，并将极大地扩大测量能力。EAL是一家具有世界独一无二的研究能力的低能核物理设施。实验室中的实验依赖于由4.5兆伏的Pelletron加速的光离子束，在不同的靶站使用电子束来进行带电粒子、伽马射线和中子光谱分析。该合同支持从美国国家静电公司收购一种名为阿尔法托斯的射频电荷交换离子源。与目前可实现的氦束强度相比，阿尔法托斯的氦束强度提高了8倍，气体消耗减少了2倍。这将使以前由于强度有限或氦-3成本过高而无法进行的几项重要测量得以进行。离子源可靠性的预期改善将提供额外的好处，例如为来自外部机构的合作者提供更高效的操作，为许多接受加速器培训的本科生和研究生提供更一致的体验，以及增加实验吞吐量。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Intense beams of atomic nuclei are essential for studies in fundamental and applied research. These ion beams can be used to reproduce and study the nuclear reactions occurring in stars and stellar explosions, characterize nuclear reactions of interest for nuclear energy and national security, and assist in the development of novel materials via ion beam analysis. Such experiments are performed at the Edwards Accelerator Laboratory (EAL) at Ohio University, where helium nuclei play a particularly important role as helium-induced nuclear reactions are ubiquitous in nature and applications. This award provides the funds to acquire an upgrade to the EAL's helium ion source which will substantially increase operational reliability and will greatly expand measurement capabilities.The EAL is a low energy nuclear physics facility with world-unique research capabilities. Experiments in the laboratory rely on light-ion beams accelerated by a 4.5 MV Pelletron, where beams are used at various target stations for charged-particle, gamma-ray, and neutron spectroscopy. This award supports the acquisition of an RF charge-exchange ion source, known as the Alphatross, from the National Electrostatics Corporation. The Alphatross provides a factor of eight improvement compared to currently achievable helium beam intensities and a factor of two reduction in gas consumption. This will enable several important measurements to be performed that were previously out of reach due to limited intensities or excessive helium-3 costs. The anticipated improvement in ion source reliability would provide additional benefits, such as more efficient operations for collaborators visiting from external institutions, a more consistent experience for the many undergraduate and graduate students who are trained on the accelerator, and increased throughput of experiments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.