Speaker
Description
The BigRIPS in-flight separator [1] at RIKEN RIBF, which began operation in March 2007, has provided a substantial variety of radioactive isotopes (RIs) as beams over a wide nuclear region, from light-mass ions to heavy RIs around U isotopes [2, 3].
The system features a two-stage configuration of achromatic separation and large ion-optical acceptance.
In addition, by using state-of-the-art radiation detectors to obtain hit timing, beam tracking, and energy loss information, RI beam particle identification is performed with a high degree of accuracy.
The beams delivered to various experimental devices have been used for studies in nuclear physics, astrophysics, and social issues related to RIs.
The in-flight RI separator is used worldwide to produce rare RIs far from the beta stability throughout the nuclear chart.
The efficacy of in-flight fission reactions of $^{238}$U or fragmentation reactions of stable nuclei located near the target RI was well demonstrated to achieve this purpose.
To obtain a large production of exotic nuclei, the following are often discussed as common problems:
First, there is a problem of how to manage the heat load and radiation damage from high-power and high-intensity primary beams in the production target and the beam dump.
Second, the question arises of how to achieve a high transmission of exotic nuclei while maintaining a high resolution for particle identification.
Third, the reduction of contaminating RI beams, where lighter RIs and intense neighboring nuclei are large compared to the target RI for experimental study is of great concern.
Fourth, unique problems may arise depending on the nuclear region of the produced beam. For example, charge states are easily mixed in the heavy nuclei region, and we have experienced unexpected background produced in proton-rich RI beams.
At BigRIPS, we have worked to continuously improve on the above difficulties and have challenged ourselves to achieve a synergistic improvement in spectrometer performance.
Achievement of such advances has facilitated our ability to effectively access new nuclear regions and occasionally detect new isotopes.
In this presentation, an overview of the recent enhancements to our achievements and the future prospects for further development of our in-flight separator will be provided.
[1] T. Kubo, Nucl. Instr. Meth. B 204, 97 (2003).
[2] Y. Shimizu et al., RI-Beam Yield Database. https://ribeam.riken.jp.
[3] C. Fukushima et al., RIKEN Accel. Prog. Rep. 56 (2023) 5.
| Email address | mitimasa@riken.jp |
|---|---|
| Classification | Techniques related to high-power radioactive ion beam production |
