Oct 3 – 7, 2022
Science Culture Center, IBS
Asia/Seoul timezone

Proof of Principle of Newly Installed Second Arm at VAMOS++ Spectrometer

Oct 4, 2022, 9:36 PM
S236 (Science Culture Center, IBS)


Science Culture Center, IBS

55 EXPO-ro, Yuseong-gu, Daejeon
Poster Session Poster Session


Yonghyun Son (Seoul National University)


The region below doubly magic 208Pb in the nuclear chart is important to understand nuclear interactions, nuclear shell evolution, and nuclear-astrophysical r-process. However, this region remains “a blank spot” in the nuclear chart due to the difficulties of producing them using conventional reactions such as fission or fragmentation.

We used multi-nucleon transfer reactions of 136Xe (7MeV/u) beam on 198Pt target to access this region. The experiment was carried out at GANIL. The VAMOS++ spectrometer [1] was used to detect and identify the projectile-like fragments (PLFs) at a grazing (40º) angle. Complementary target-like fragments (TLFs) velocity was measured by a newly constructed second arm, composed of a vacuum chamber and multi-wire proportional counter, which was installed at the 55º angle. The prompt and delayed gamma rays from nuclei of interest were measured by AGATA HPGe tracking array with 34 crystals [2] placed around the target position and 4 EXOGAM HPGe clover detectors [3] placed at the end of the second arm, respectively.

The second arm is essential for this experiment since the nuclides of interest are on the TLFs. The particle identification through the VAMOS++ spectrometer is only possible for the PLFs, thus, the TLFs are identified indirectly. By referring to the complementary PLFs identified by VAMOS, the information of TLFs measured by the second arm is used for indirect information to help to determine TLF identification. In this presentation, 1) the development process of the second arm, such as the GEANT4 simulation result, as well as the proof of principle result of the second arm from the experimental data, namely 2) detection of isomeric states from TLFs and 3) indirect TLF determination using coincidence VAMOS and the second arm will be discussed.

[1] M. Rejmund et al., Nucl. Instr. And Meth. A, 646, 184-191 (2011)
[2] S. Akkoyun et al., Nucl. Instr. And Meth. A, 668, 26-58 (2012)
[3] J. Simpson et al., Acta Phys. Hung. New Ser. Heavy Ion Phys. 11, 159 (2000)

Primary authors

Dieter Ackermann (GANIL) Navin Alahari (GANIL) Andrey Andreev (Univ. of York) Sunghan Bae (IBS CENS) Ranabir Banik (VECC) Soumik Bhattacharya (VECC) Sarmishtha Bhattacharyya (VECC) Kyungyuk Chae (SKKU) Youngju Cho (Seoul National University) Seonho Choi (Seoul National University) Gilles De France (GANIL) Francois Didierjean (IPHC) Jeremie Dudouet (IP2I Lyon) Chloe Fougeres (GANIL) George Fremont (GANIL) Joan Goupil (GANIL) Gyoungmo Gu (SKKU) Jeongsu Ha (KU Leuven) Yoshikazu Hirayama (KEK Wako Nuclear Science Center) Sunchan Jeong (KEK) Philipp John (TU Darmstadt) Chanhee Kim (Department of Physics, Sungkyunkwan University, Republic of Korea) Sohyun Kim (Department of Physics, Sungkyunkwan University, Republic of Korea) Yunghee Kim (Center for Exotic Nuclear Studies, IBS) Wolfram Korten (CEA) Antoine Lemasson (GANIL) Paola Marini (CENBG) Hiroari Miyatake (KEK Wako Nuclear Science Center,) Momo Mukai (RIKEN Nishina Center) Gopal Mukherjee (VECC) Toshitaka Niwase (KEK Wako Nuclear Science Center) Joochun Park (IBS CENS) Rosa Maria Perez Vidal (INFN-LNL) Diego Ramos (GANIL) Francesco Recchia (Univ. of Padova) Maurycy Rejmund (GANIL) Kseniia Rezynkina (INFN-Padova) Marco Rosenbusch (RIKEN) Peter Schury (RIKEN) Yonghyun Son (Seoul National University) Jean-Charle Thomas (GANIL) Deby Treasa (CENBG) Igor Tsekhanovich (CENBG) Ablaihan Utepov (GANIL) Yutaka Watanabe (KEK Wako Nuclear Science) Giacomo de Angelis (INFN-LNL)

Presentation materials