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Shoji Nagamiya

Publications and source records attributed to Shoji Nagamiya.

4 recordsLinked to original sources

The atomic bomb: its history and the struggles of scientists

In this article, I trace the early historical developments that ultimately led to the creation of the atomic bomb. Even after the completion of weapons, many scientists continued to argue that nuclear armaments were indispensable for maintaining the global balance of political power [1]. This study focuses on several scientists who confronted profound moral dilemmas concerning the use of bombs against Japan. Some openly opposed its deployment. Others sought to warn a Japanese physicist in the hope of averting further devastation. Still, others expressed deep remorse in its aftermath. In addition, the experience of an individual directly affected by the bombing is discussed. By examining these episodes, this article aims to contribute to the ongoing discourse on how scientific research should be guided by ethical principles in the future.

physics.hist-ph

RHIC Program, Its Origin and Early Results

At the Brookhaven National Laboratory, experimental efforts with heavy-ion accelerators started at the AGS synchrotron in 1984 and then at the Relativistic Heavy Ion Collider (RHIC) in 1991. This chapter of a future book describes how several scientific collaborations were established and how features of the quark-gluon plasma were revealed from the four RHIC experiments during the first five years of RHIC operation.

nucl-ex

Heavy-Ion Collisions toward High-Density Nuclear Matter

In the present paper, the current efforts in heavy-ion collisions toward high-density nuclear matter will be discussed. First, the essential points learned from RHIC and LHC will be reviewed. Then, the present data from the STAR Beam Energy Scan are discussed. Finally, the current efforts, NICA, FAIR, HIAF, and J-PARC-HI (heavy ion) are described. In particular, the efforts of the J-PARC-HI project are described in detail.

nucl-ex

Towards a novel laser-driven method of exotic nuclei extraction-acceleration for fundamental physics and technology

The measurement of properties of exotic nuclei, essential for fundamental nuclear physics, now confronts a formidable challenge for contemporary radiofrequency accelerator technology. A promising option can be found in the combination of state-of-the-art high-intensity short pulse laser system and nuclear measurement techniques. We propose a novel Laser-driven Exotic Nuclei extraction-acceleration method (LENex): a femtosecond petawatt laser, irradiating a target bombarded by an external ion beam, extracts from the target and accelerates to few GeV highly-charged nuclear reaction products. Here a proof-of-principle experiment of LENex is presented: a few hundred-terawatt laser focused onto an aluminum foil, with a small amount of iron simulating nuclear reaction products, extracts almost fully stripped iron nuclei and accelerate them up to 0.9 GeV. Our experiments and numerical simulations show that short-lived, heavy exotic nuclei, with a much larger charge-to-mass ratio than in conventional technology, can be obtained in the form of an energetic, low-emittance, high-current beam.

physics.acc-ph