International Workshop on Frontiers of Active Targets and Nuclear Spectroscopy (FATaNS2026)

8 Jun 2026, 09:00 → 10 Jun 2026, 18:00 Asia/Tokyo

Nishina Hall (E02) (RIKEN)

Daisuke Suzuki (Department of Physics, University of Tokyo), Hidetoshi Yamaguchi (CNS, the University of Tokyo), Shinsuke Ota (RCNP, Osaka University), Tadaaki Isobe (RIKEN), Tatsuya Furuno (Osaka University), Tokuro Fukui (Kyushu University)

International Workshop on Frontiers of Active Targets and Nuclear Spectroscopy  (FATaNS2026) will be held at the Nishina Hall of the RIKEN Nishina Center on June 8 to 10, 2026. FATaNS2026 is a post-satellite workshop following the international conference ARIS2026 in Fukushima (June 1 to 7). 

Research on nuclear spectroscopy and nuclear reactions using active targets has advanced significantly in recent years. Active targets have substantially enhanced experiments with radioactive-isotope (RI) beams by enabling high-luminosity measurements even with low-intensity beams, while achieving extremely low detection thresholds and wide solid-angle coverage. These capabilities have led to important results that provide new insights into the nuclear structure of open quantum systems, clustering phenomena, collective motion and shell evolution in unstable nuclei, as well as astrophysical nuclear reactions relevant to nucleosynthesis.

 At the core of active-target technology lies the Time Projection Chamber (TPC). Substantial progress has been made in detector design, readout technologies, simulation frameworks, and data-analysis methods for TPC-based systems. In parallel, new active-target projects are underway at accelerator facilities worldwide. Beyond active targets, TPCs also play essential roles in a wide variety of nuclear-physics experiments that utilize high-precision three-dimensional tracking, and these broader applications have also seen rapid technical and scientific developments.

 Given the expansion of the community and recent technological advances, there is a growing need to share technical expertise, exchange operational and analysis experience, and discuss strategies for maximizing scientific output in experiments employing active targets and TPCs.

 The purpose of this workshop is to review recent research results obtained with active targets and TPC-based detectors and to provide a forum for discussing future research directions and experimental programs. In addition, the workshop aims to promote deeper discussions on theoretical studies related to nuclear spectroscopy and nuclear reactions with active targets, thereby fostering closer integration between experimental and theoretical efforts.

Topics

The main topics include:

• Experimental results in nuclear spectroscopy and nuclear reactions using active targets and TPCs

• Theoretical studies related to nuclear structure and reactions, nucleosynthesis

• Development of active-target detector systems

• Data-analysis techniques for active-target experiments

• Future experimental programs employing active targets

 

Invited speakers (confirmed)

D. Bazin (FRIB)
F. Endo (RIKEN Nishina Center)
Y. Funaki (Kanto Gakuin Univ.)
T. Furuno (Univ. of Fukui)
J. Giovinazzo (CENBG) 
C. Hunt (TRIUMF)
Y. Ichikawa (Tohoku Univ.)
K. Nakamura (Tohoku Univ.)
T. Oishi (National Instute of Technology, Ibaraki College)
W. Pu (SUSTech)
S. Sakajo (Univ. of Osaka)
C. Soomi (IBS)
H. Togashi (Kyoto Univ.)
B. Tsang (FRIB)
K. Uzawa (JAEA)
N. Zhang (IMP)
Z. Zhang (IMP)

Contributed talks

The abstract submission form is available at https://indico2.riken.jp/event/5484/abstracts . The deadline is March 8.  

Registration

The registration form is available at https://indico2.riken.jp/event/5484/registrations . The deadline is May 17. 

Banquet

The workshop banquet will be held in the evening of June 8. The fee will be around 5,000 JPY/person.

Venue

The workshop will be held onsite at the Nishina Hall of the RIKEN Nishina Center. 

Accommodation

Please make your own hotel arrangements by yourself. Those who wish to stay at the guest house are asked to contact the workshop organizers. 

Support

We will support students and early-career researchers to encourage their participation. Domestic travel and local expenses will be fully or partially covered based on the availability of funds. The application form is found in the online registration form.  

Important dates

March 8: Deadline for abstract submission
May 17: Deadline for registration
June 8 to 10: Workshop

Hosts

RIKEN Nishina Center
Center for Nuclear Study, the University of Tokyo
Quark Nuclear Science Institute, the University of Tokyo
Research Center for Nuclear Physics, the University of Osaka

Organizing committee

Tokuro Fukui (Kyushu Univ.), Tatsuya Furuno (Univ. Fukui), Tadaaki Isobe (RIKEN),  Shinsuke Ota (RCNP), Daisuke Suzuki (UTokyo), Hidetoshi Yamaguchi (CNS)

Monday 8 June

Registration

1 Opening address

Speaker: Dr Daisuke Suzuki (Department of Physics, University of Tokyo)

Session

Convener: Chair: Daisuke Suzuki

2 Recent results and new prospects with the AT-TPC

This contribution will review some of the results obtained with the AT-TPC, as well as recent ongoing developments in the analysis methodology. Furthermore, future prospects for improving the scientific reach of this active target detector will be discussed.

Speaker: Daniel Bazin (Michigan State University)

Bazin - Talk.pdf

3 TBA

Speaker: Betty Tsang

4 Present status of study of alpha condensation

Funaki's talk

Speaker: Yasuro Funaki (Kanto Gakuin University)

11:40 Lunch

Session

Convener: Chair: Hidetoshi Yamaguchi

5 AT-TPC campaign at RCNP

In FY2025, the world’s largest active target, the AT-TPC developed at FRIB, was installed at the radioactive-ion beam line (EN course) of the Research Center for Nuclear Physics (RCNP), Osaka University. In this campaign, six experiments were carried out. Five of these experiments involved radioactive-ion beams, in which reactions of secondary beams at 20–30 MeV/u ($^{11}$Be, $^{12}$Be, $^{13}$B, $^{17}$N, and $^{17}$C) with a deuterium target were measured. The secondary beams were produced via projectile fragmentation of $^{18}$O beams at 60 MeV/u and $^{22}$Ne beams at 50 MeV/u on $^{9}$Be targets. The AT-TPC was operated with C$_3$D$_8$ gas at 450 Torr (isotopic purity of 99%) that served also a deuterium target. The (d,p), (d,d), (d,d'), (d,t), and (d,$^3$He) reactions were measured. The mass thickness of the deuterium target was 42 mg/cm$^2$.
In this presentation, after introducing each experiment, we report on the experimental setup at the EN course and the current status of the AT-TPC data analysis.

Speaker: Tatsuya Furuno (University of Fukui)

20260608_furuno_upload.pdf

6 Studying the Equation of State of Dense Nuclear Matter Through Xe + Sn Reactions in the SπRIT TPC

Heavy ion reactions can be used to provide constraints on the density dependence of the Equation of State (EoS) of dense nuclear matter, helping constrain the EoS of neutron stars. The SAMURAI Pion-Reconstructing and Ion-Tracker (SπRIT) TPC is a device for measuring the pion yields of heavy ion reactions using the SAMURAI magnet at RIKEN for providing these constraints. In 2024 an experiment was performed using the SπRIT TPC at RIBF at RIKEN to compare pion yields for 124Xe+112Sn and 136Xe+124Sn reactions. For this experiment, a modified version of the FRIBDAQ was used with GET for improved reliability. TPCs can present certain analysis challenges. The SπRITROOT analysis code is used to obtain particle identification and momentum of particles coming out of the collisions into the TPC by fitting the curve of the tracks in the SAMURAI magnet. Space charge from the heavy beam passing through the TPC must be corrected for by modeling the sheet charge of the ionized gas. Efficiency can be found through simulating pions embedded into real data to account for geometry and the density of tracks in high multiplicity events.

Speaker: Curtis Hunt (TRIUMF)

7 Direct Neutron Capture in Continuum QRPA: Impact of Collectivity and Resonances on the Low-Energy Cross Sections

Neutron capture plays a crucial role in nuclear reactors and nucleosynthesis.
In neutron-rich nuclei near the drip line, the low level density suppresses compound
processes, and direct neutron capture (DC) is expected to contribute significantly to
r-process nucleosynthesis.
A quantitative description of DC requires detailed information on low-lying states
(spectroscopic factors) and resonances.

In this work, we develop a direct neutron capture model based on the continuum
quasiparticle random phase approximation (QRPA).
The present framework consistently describes the collectivity of low-lying states
and resonances, as well as pairing correlations,
with a proper treatment of continuum states.
This approach goes beyond conventional potential (mean-field) models,
which lack many-body correlations and continuum coupling.

We apply this model to neutron-rich nuclei, 89Ge(n,g)90Ge and 91Zn(n,g)92Zn,
using Skyrme energy density functionals (SLy4 and SkM*).
For 89Ge, we find that the pygmy quadrupole resonance enhances the neutron
capture cross section through gamma decay to the collective first 3- state.
For 91Zn, the s-wave capture is enhanced by a quasiparticle resonace,
which originates from a Hartree-Fock bound state that becomes an unbound resonance
due to pairing correlations.
These effects are absent in conventional potential models.

Our results demonstrate that both low-lying collective states and resonances,
including quasiparticle resonances, can play a significant role in direct
(and doorway) neutron capture.

Speaker: Teruyuki Saito (Niigata Univ.)

t_saito_20260608.pdf

14:20 Coffee break

Session

Convener: Chair: Sunghoon (Tony) Ahn

8 (Online) Development of MATE and its applications in nuclear structure studies

Over the past few years, a new active-target detector, MATE (Multi-purpose Active-target Time projection chamber for nuclear Experiments), has been developed at IMP-CAS. The primary goal is to investigate exotic phenomena, such as the shell evolution in unstable nuclei. In this presentation, I will introduce the current status and performance of MATE, together with several related experiments. In particular, I will introduce the study of new proton magicity at Z=6 through the $^{11}$C+$\alpha$ inelastic scattering experiment performed at RIBLL1-HIRFL. In addition, some experimental plans will also be mentioned.

Speaker: Zhichao ZHANG (Institute of Modern Physics, Chinese Academy of of Sciences)

FATaNS2026_zhangzc.pdf

9 GEM based TPC "HypTPC" and its upgrade with thin Glass GEM

We developed the GEM-based Time Projection Chamber, HypTPC, for the hadron experiment at J-PARC. The HypTPC has a unique design that allows for the installation of the experimental target inside the field volume, thereby achieving large acceptance. Consequently, we need to inject the beam into the TPC active area, and the HypTPC should have a high rate capability.
To achieve this, we adopted a triple GEM configuration with thicknesses of 100 μm, 50 μm, and 50 μm, along with a gating grid wire system. The first experiment with the HypTPC, the JPARC E42 experiment to search for the H-dibaryon, was successfully completed in 2021. In this experiment, we injected a beam with a rate of about 10⁶ Hz into the HypTPC, and no GEMs failed during the experimental period. However, we also found that the 10⁶ Hz beam intensity is close to the operational limit for the current HypTPC. To improve the rate capability, we have begun developing a new type of GEM, the Glass GEM.
In the current HypTPC, the GEMs use Polyimide and Liquid Crystal Polymer as the insulating material, which is widely used for TPC detectors. Recently, the Glass GEM has been developed for neutron imaging [1]. The Glass GEM offers several advantages over the conventional GEM for the following reasons. The flatness is better because glass is stiffer compared to conventional one. A flat GEM can create a uniform electric field, leading to a uniform gain. Glass does not contain organic material, so the probability of shorting the electrodes due to sparks is lower compared to the conventional GEM, which is an organic material.
However, producing thin Glass GEMs is challenging because glass is fragile, and the thickness was previously limited to about 500 μm. Here, a multilayer configuration with thin GEMs is essential for rate capability to avoid ion backflow. We have developed a 100 μm thick GEM in collaboration with NSC company, which has specialized techniques for chemical etching.Recently, we succeeded in measuring the signal with triple 100 μm Glass GEMs. In this workshop, we will present an overview of the HypTPC and the current status of the thin Glass GEM development to achieve high rate capability.

Speaker: Yudai Ichikawa (Tohoku University)

GlassGEM_202606_ichikawa.pdf

15:50 Coffee break

Session

Convener: Chair: Tatsuya Furuno

10 (Online) Recent results on nuclear structure studies with ACTAR TPC

ACTAR TPC is part of a new generation of active-target detectors specifically designed to meet the requirements of nuclear-structure investigations with radioactive beams in inverse kinematics. Commissioned in 2018 [1], the system has since been used in several experiments [2,3]. This talk will present results from two recent experiments at the GANIL and TRIUMF facilities, aimed at studying several neutron- and proton-rich nuclei.

The first transfer-reaction experiment with ACTAR TPC used an SPIRAL1 beam of $^{20}$O to measure proton-removal (d,$^3$He) [2] and neutron-removal (d,t) reactions. Filled with a gas mixture of 90% CD$_2$ and 10% C$_4$H$_{10}$ at 951 mbar, the TPC was coupled to an array of silicon pad detectors, enabling measurements of the residual energies of the recoiling light particles. By characterising the excited states in the final $^{19}$N and $^{19}$O nuclei, a simultaneous investigation of both proton and neutron shell evolution across the oxygen isotopic chain was performed. The results strongly support an evolution of shell-model magic gaps driven by the tensor component of the nucleon-nucleon force [4].

A more recent experimental campaign was carried out successfully at TRIUMF in 2025. Using proton and deuteron targets, experiments with $^{11}$Li and $^{20}$Mg beams were performed to investigate properties of near-dripline nuclei. This talk will provide an overview of the campaign and present preliminary results for selected physics cases.

References
[1] B. Mauss et al., Nucl. Instrum. Methods Phys. Res. A: Accel. Spectrom. Detect. Assoc. Equip. 940, 498–504 (2019).
[2] J. Lois Fuentes, “Complete spectroscopy of 16C and 20O with solid and active targets using transfer reactions USC”, PhD thesis (Universidade de Santiago de Compostela, 2023).
[3] A. Ortega Moral et al., Phys. Rev. C 112, L061302 (2025).
[4] T. Otsuka et al., Rev. Mod. Phys. 92, 15002 (2020).

Speaker: Miguel Lozano-González (IGFAE - USC)

11 Investigation of the shell inversion in 10Li via a d(11Be,3He)10Li reaction with the Active Target Time Projection Chamber (AT-TPC)

The evolution of shell structure in unstable nuclei is a hot topic in modern nuclear physics. In neutron-rich nuclei, inversions in ordering of single-particle orbitals have been observed, which can lead to the disappearance of conventional magic numbers. Among the N=7 isotones, the relative ordering of the neutron s- and p-orbitals in $^{10}$Li has been the subject of long-standing debate. While theoretical calculations consistently predict an inversion of s- and p-orbitals in the ground-state of $^{10}$Li, experimental results remain inconclusive.
Given that the ground state of $^{11}$Be is known to have a dominant s-wave component (∼80%) with a d-wave admixture (∼20%). As a result, the single-proton transfer reaction $^{11}$Be(d,$^{3}$He)$^{10}$Li preferentially populates s-wave resonances in $^{10}$Li. By precisely measuring the resonance energy of this state, we aim to clarify whether an inversion between the s and p orbitals occurs in $^{10}$Li. As part of the AT-TPC campaign, the experiment was performed in 2025 at the EN course of the Research Center for Nuclear Physics (RCNP), Osaka University. A primary ¹⁸O beam was used to produce the secondary beam ¹¹Be with the energy around 26.5 MeV/u. The ATTPC is filled with C$_3$D$_8$(~460 torr). The scattered light particles (H, He) were detected within the AT-TPC, while the heavy ions (Li, Be) were measured by the telescope located at the downstream of the AT-TPC.
This talk will present preliminary results from the inelastic scattering $^{11}$Be(d,d’)$^{11}$Be, as well as the excitation energy spectrum of $^{10}$Li populated via the $^{11}$Be(d,$^{3}$He) reaction.

Speaker: Haoyu GE (Peking University, China)

ghy_FATaNS2026_pdf.pdf

18:00 Social dinner

Tuesday 9 June

Session

Convener: Chair: Soomi Cha

12 High pressure xenon gas TPC development to search for neutrinoless double beta decay

We are developing a high‑pressure xenon gas time projection chamber (TPC) to search for neutrinoless double beta decay (0νββ). Observing 0νββ would reveal a key unresolved property of neutrinos—whether they are Majorana particles. Because 0νββ is an extremely rare and monoenergetic process, the detector must simultaneously achieve a large target mass, excellent energy resolution, and ultra‑low background. A high‑pressure xenon gas TPC is a promising candidate: large mass is obtained by operating at high pressure, high energy resolution is realized using gaseous xenon with electroluminescence amplification, and low background is achieved through event‑by‑event track reconstruction.
We are developing an original readout structure, the Electroluminescence Collection Cell (ELCC), installed on the readout plane of the high‑pressure xenon gas TPC. The ELCC is a pixelated electroluminescent light‑readout mechanism that enables both high energy resolution and detailed track reconstruction. To date, we have demonstrated the ELCC concept using a small 10‑L prototype and evaluated its performance at the 0νββ Q‑value (2.5 MeV) with a larger 180‑L prototype. We are also developing larger, multi‑channel devices to gain operational experience toward a physics‑scale 1000‑L detector. For example, as feedthrough discharge becomes a concern at longer drift lengths, we are preparing to operate a CW boost circuit inside the vessel and to modularize the readout system for improved reliability.
In this workshop, we will present the performance of our high‑pressure xenon gas TPC and the current status of its technological development.

Speaker: Kiseki Nakamura (Tohoku University)

kisekinakamura_20260609_FATaNS2026.pdf

13 Measurement of $^{12}$C neutron inelastic scattering cross section using MAIKo+ active-target Time Projection Chamber (TPC)

The triple-alpha reaction is important not only for determining the abundance of $^{12}$C, but also for understanding the overall nucleosynthesis in the universe. Right after the Big Bang, elements heavier than helium were scarcely synthesized due to the absence of stable nuclei with mass numbers 5 and 8. The triple-alpha reaction overcomes this bottleneck and is considered one of the starting points for the synthesis of heavier elements. To determine the triple-alpha reaction rate, it is necessary to determine the probability of deexcitation of $^{12}$C from the $3\alpha$ resonance states to the ground state.

So far, only electromagnetic decay has been considered for deexcitation from the $3\alpha$ resonance states of $^{12}$C. However, in high-density environments, such as supernova explosions, the contribution of inelastic scattering with neutrons, which are not affected by the Coulomb barrier, becomes significant[1]. Therefore, we aim to determine the rate enhancement of the triple-alpha reaction in dense conditions.

Since the lifetime of the $3\alpha$ resonance state is extremely short, a direct measurement of the deexcitation process induced by neutron inelastic scattering is impossible. Instead, we measure the time-reversal reaction, $^{12}$C$(n,n')$, where the ground state of $^{12}$C is excited to the $3\alpha$ resonance states by neutron inelastic scattering, and then derive the deexcitation cross section using the principle of detailed balance.

We performed a cross-section measurement of the $^{12}$C$(n,n')$ reaction at the cyclotron facility of the Research Center for Accelerator and Radioisotope Science, Tohoku University. Quasi-monoenergetic neutron beams with $E_n = 9.4$, 10.9, 11.7, and 12.5 MeV were produced via the $^1$H$(^{13}$C,$n)$ reaction and injected into the MAIKo+ active-target TPC[2]. The MAIKo+ TPC was operated with $i$-$\mathrm{C}4\mathrm{H}{10}$(10%) + $\mathrm{H}_2$(90%) at 0.1 atm, enabling the detection of low-energy $\alpha$ particles emitted from the excited $^{12}$C $3\alpha$ resonance states.

In addition, two liquid scintillation counters were installed downstream of the MAIKo+ TPC at 170 mm and 4505 mm. Using these detectors, we measured the neutron beam intensity and evaluated the beam energy.

In this presentation, we will show TPC data of $^{12}$C neutron inelastic scattering events recorded in MAIKo+, present the analysis results of neutron counting and energy determination using the liquid scintillation counters, and report the measured cross section of the $^{12}$C$(n,n')$ reaction.

References

[1] Beard et al., Phys. Rev. Lett. 119, 112701 (2017).
[2] T.Furuno et al., Nucl. Instrum. Methods Phys. Res. A 908, 215 (2018).

Speaker: YIFAN LIN (The University of Osaka)

FATaNS26.pdf

10:20 Coffee break

Session

Convener: Chair: Fumitaka Endo

14 Probing Shell Evolution in 16C and 12Be with ATTPC and Solenoidal Spectrometers

The evolution of shell structure in neutron-rich nuclei remains a central topic in nuclear physics, particularly the disappearance of traditional magic numbers and the persistence or emergence of sub-shell closures far from stability. In this presentation, we report recent progress on direct-reaction studies of light exotic nuclei ${}^{16}$C and ${}^{12}$Be using ATTPC and solenoidal spectrometers, with emphasis on the N = 8 and Z = 6 shell structures.

First, we present the result of probing ${}^{16}$C with inelastic reactions using Active Target Time Projection Chamber coupled to solenoidal magnetic field. The inelastic-scattering results indicate that the third $2^+$ state is dominated by proton excitation, giving evidence for the persistence of the Z = 6 proton sub-shell closure in neutron-rich carbon isotopes. Second, we discuss ${}^{12}$Be's result from ${}^{12}$Be(p,d)${}^{11}$Be using similar experimental setup, where the measured single-particle strength provides direct evidence for the breakdown of the traditional N = 8 shell closure in the beryllium isotopic chain.

Finally, we report the current progress of the ${}^{12}$Be(d,p)${}^{13}$Be experiment performed at RCNP using the AT-TPC with downstream charged-particle identification (silicon+GAGG). Together, these studies demonstrate the power of active-target to probe shell evolution in weakly bound nuclei.
To address these questions, we carried out the ${}^{12}{\rm Be}(d,p){}^{13}{\rm Be}$ experiment at RCNP using the AT-TPC together with downstream zero-degree silicon for charged particle detection. The measurement has been completed, and we have proceeded to the data reconstruction and analysis stage. But the analysis project is still in an early phase without drawing final conclusion yet. In this meeting, we will report the present status of the experiment and share our early-stage data analysis and reveal key features of the dataset.

Speaker: Weiliang Pu (Southern University of Science and Technology)

Probing Shell Evolution in 16C and 12Be with ATTPC and Solenoidal Spectrometer.pdf

15 Search for alpha condensed state in $^{24}$Mg with AT-TPC

It is well known that many light nuclei exhibit prominent cluster structures, and the $\alpha$ particles play an important role as constituents of the cluster state. Among the cluster states, $\alpha$-condensed states are of great interest because they are analogous to a Bose-Einstein condensate in which all the $\alpha$ clusters are condensed into the single lowest-energy orbit. The theoretical calculation by T. Yamada $\textit{et al.}$ predicted that the $\alpha$-condensed states could exist up to $A=40$. However, the $\alpha$-condensed states in $A≥16$ have never been experimentally established. Therefore, we conducted an experiment to search for the $\alpha$-condensed state in $^{24}\textrm{Mg}$ by measuring the $^{12} \textrm{C} + ^{12} \textrm{C}$ scattering with AT-TPC developed at Michigan State University.
This experiment was part of the experiments in the AT-TPC campaign at Research Center for Nuclear Physics, the University of Osaka. In this experiment, a $^{12}\textrm{C}$ beam at $67.7\; \textrm{MeV}$ was injected into AT-TPC filled with iso-$\textrm{C}_4\textrm{H}_{10}$ gas at about $0.1\; \textrm{atm}$. In the present talk, I will report on the experimental setup and data analysis.

Speaker: Soki SAKAJO (The University of Osaka)

slide_0607up.pdf

11:40 Lunch

Session

Convener: Chair: Daniel Bazin

16 Advancement of microscopic nuclear fission theory based on the non-equilibrium Green's function method

Uzawa's talk

Speaker: Kotaro Uzawa (Japan Atomic Energy Agency)

2026.6.8.pdf

17 Upgrade and Performance of the TexAT_v2 Active-Target TPC for the 14O(α,p)17F Measurement

Active-target time projection chambers (TPCs) have become powerful tools for experimental studies of nuclear reactions. Direct measurements of astrophysically important (α,p) reactions at low center-of-mass energies remain experimentally challenging due to their low cross sections, requiring stable operation under relatively high beam intensities. To overcome these limitations and extend the sensitivity in the astrophysically relevant energy region, an upgrade of the Texas Active Target TPC was undertaken.
The system was upgraded to the TexAT_v2 configuration with the primary goal of enhancing the detection efficiency for low-energy protons and improving overall acceptance. The upgrade included modifications of the field cage structure, implementation of additional silicon–CsI(Tl) detector arrays, and optimization of the detector geometry. The upgraded setup was combined with the LILAK analysis framework, which provides pulse-shape analysis and track reconstruction tailored to active-target experiments, enabling reliable identification of reaction protons and extraction of reaction cross sections.
In this presentation, we describe the upgrade of TexAT to the TexAT_v2 configuration and its performance. The improvements in detector configuration and data analysis will be discussed, and the 14O(α,p)17F measurement will be introduced as an example demonstrating the capabilities of the upgraded system.

Speaker: Chaeyeon Park (IRIS/IBS)

260609_FATaNS_CY.pdf

18 (Online) Gamow-Teller transition studies within Quasiparticle Phonon Model

One of the successful tools for nuclear structure studies is the quasiparticle random phase approximation (QRPA) with the self-consistent mean-field derived from the Skyrme energy density functional (EDF). The framework allows to relate the properties of the ground states and excited states through the EDF. There is the discrepancy between the QRPA predictions and the measurements for low-energy 1+ spectrum of the daughter nucleus, see as an example [1].
The number of low-lying 1+ states is naturally reproduced by the inclusion of the tensor correlations and the coupling between one- and two-phonon terms in the 1+ wave functions [2-4]. We applied the influence of the phonon-phonon coupling on the probability of the neutron emission occurring at very small quantity of energy available in β-decay. Onset of delayed neutron emission in Cd isotopic chain is discussed.
[1] A. Etilé et al., Phys. Rev. C 91, 064317 (2015).
[2] A.P. Severyukhin et al., Phys. Rev. C 90, 044320 (2014).
[3] A.P. Severyukhin et al., Phys. Rev. C 95, 034314 (2017).
[4] A.P. Severyukhin et al., Phys. Rev. C 101, 054309 (2020).

Speaker: Alexey Severyukhin (JINR)

SeveryukhinRIKEN.pdf

14:10 Coffee break

Session

Convener: Chair: Jie Chen

19 (Online) Development of low-pressure micromegas TPC and application in nuclear astrophysics with high intense primary beams

A novel double-mesh micromegas TPC has been developed in the MATE collaboration. This two-stage amplification structure achieves high gain and low ion backflow at low low-pressure. As a tracking detector, it is successfully applied in the direct measurements of the 12C+12C fusion reaction at stellar energies with beam intensity of 80-90 puA. In this report, I will present the recent 12C+12C experimental result and the extension into (p,a) and (a,d) direct measurements with mA level high beam intensity.

Speaker: Dr Ningtao Zhang (Institute of Modern Physics, CAS, China)

202606_FATaNS_NingtaoZhang.pdf

20 Recent Progress and Future Developments of the CAT-M

Speaker: Fumitaka Endo

20260609_FATaNS2026.pdf

21 (online) Reaction and decay studies with ACTAR TPC

Speaker: Jérôme Giovinazzo

2026-06_FATaNS_Giovinazzo_pub.pdf

Wednesday 10 June

Session

Convener: Chair: Naoyuki Itagaki

22 Role of Nucleon Effective Mass in Dense-Matter Microphysics for Supernovae and Neutron Stars

Togashi's talk

Speaker: Hajime Togashi (Kyoto University)

23 Spin correlation and entanglement in two-proton emissions

Spin correlation is a fundamental quantity to characterize the quantum entanglement.
In the nuclear physics, quantum-entangled states may exist in various systems and reactions.
We theoretically show that a two-proton (2p) emitter with a diproton-correlated initial state can act as a source of spin-entangled proton pairs.
For the light 2p emitters, Be-6 and Ne-16 nuclei, a violation of the local-hidden-variable (LHV) bound in terms of Clauser-Horne-Shimony-Holt (CHSH) inequality is suggested.
For this purpose, the time-dependent three-body model has been utilized.
In this contribution, we also discuss how the 2p-spin correlation is affected by (i) the proton-proton interaction, (ii) democratic or sequential character, and (iii) diproton correlation in the initial state.

Speaker: Dr Tomohiro OISHI (RIBF, RIKEN)

2026_0610_RIKEN_FATaN.pptx

10:00 Coffee break

Session

Convener: Chair: Yasuro Funaki

24 Development and physics programs of active target TPC at CENS

Active Target Time Projection Chambers (AT-TPCs) are advanced particle detectors that allow precise measurements of astrophysically important nuclear reactions. A new Active Target TPC for Multiple nuclear physics eXperiments (AToM-X) is being developed at the Center for Exotic Nuclear Studies (CENS). It consists of a highly segmented Time Projection Chamber (TPC) using a Micromegas, a field cage, and silicon and CsI detector arrays. It enables high resolution measurements of the 3-dimensional particle tracks, energy, and position with the high detection efficiency. By utilizing sing the AToM-X, proton upscattering on the Hoyle state in 12C, 34Ar(a,p)37K, 10Be(p,a)7Li, and 17F(a,p)20Ne will be measured at JAEA and CRIB in RIKEN. Details of the current development status and the future plans will be presented.

Speaker: Dr Soomi Cha (Center for Exotic Nuclear Studies, Institute for Basic Science)

SMCha-FATaNS2026_AToM-X.pdf

25 Clustering feature of light nuclei

In this presentation, I will focus on the clustering features of light nuclei and show some recent applications. One is 22Mg. The study of the 22Mg is highly important in nuclear physics because it sits at the crossroads of alpha-particle clustering, mirror symmetry breaking, and nuclear astrophysics. I will show the results of the 14O+alpha+alpha model calculation on this nucleus. Also, 12C+12C structure on 24Mg is presented, which is important in explaining the source or X-ray super burst. Finally, three alpha structure of 12C induced by the p+11B reaction is discussed in connection with cancer treatment.

Speaker: Naoyuki Itagaki (Osaka Metropolitan University)

26 Discussion for future projects

27 Concluding remarks

Speaker: Daniel Bazin (Michigan State University)