The N=126 factory: A new facility to produce very heavy neutron-rich isotopes

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:463

Article; Proceedings Paper

Savard, G.^1,2  Brodeur, M.³  Clark, J. A.^1,4  Knaack, R. A.¹  Valverde, A. A.^1,3 

[1] Argonne Natl Lab, Phys Div, 9700 S Cass Ave, Argonne, IL 60439 USA

[2] Univ Chicago, Dept Phys, Chicago, IL 60637 USA

[3] Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA

[4] Univ Manitoba, Dept Phys & Astron, Winnipeg, MB R3T 2N2, Canada

关键词: Radiofrequency quadrupole;    Beam transport;    Radioactive ion beams;    Beam cooling;   

DOI  :  10.1016/j.nimb.2019.05.024

来源: Elsevier

【 摘 要 】

A new facility, the N = 126 factory, is currently under construction at Argonne National Laboratory. It will use multi-nucleon transfer reactions to create neutron-rich isotopes of very heavy elements for studies of interest to the formation of the A similar to 195 abundance peak in the r-process. This region of the nuclear chart is difficult to access by standard fragmentation or spallation reactions and as a result has remained mostly unexplored. The nuclei of interest, very neutron-rich isotopes around Z = 70-95, will be produced by multi-nucleon exchange of a high intensity 10 MeV/u heavy-ion beam on the most neutron-rich stable isotopes of heavy elements such as Pt-198 and U-238. This reaction mechanism can transfer a large number of neutrons and create very neutron-rich isotopes with larger than mb cross-section. The reaction mechanism is a nuclear surface process and the reaction products come out close to the grazing angle, which makes them very difficult to collect. The N = 126 factory circumvents this difficulty by using a unique large high-intensity RF gas catcher, similar to the one currently in operation at CARIBU, to collect the target-like reaction products and transform them into a low-energy beam that will then be mass separated with a medium resolution electromagnetic separator (Delta M/M similar or equal to 1/1500), followed by an RFQ buncher and an MR-TOF (Delta M/M similar or equal to 1/100,000) system. The extracted radioactive beams will be essentially pure and available at low-energy for mass measurements with the CPT mass spectrometer or decay study with the X-array.

【 授权许可】

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