Nuclear Physics in Greece

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RECFA, Athens-Greece, 10/11/2023

Nikolas Patronis

n_TOF Physics Coordinator

CERN & Univ. of Ioannina

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The Hellenic Nuclear Physics community

Institutes:

• National and Kapodistrian University of Athens, Department of Physics
• National Technical University of Athens, Department of Physics
• Aristotle University of Thessaloniki
• University of Ioannina
• Hellenic centre for marine research, Anavysos
• NCSR “Demokritos”, Athens

Our younger colleagues:

BSc: ~40; MSc: ~15; PhD: ~25; post-docs:~10

Faculty members, Researchers: 25

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National and Kapodistrian University of Athens

• Nuclear Medical Imaging (SPECT-Lab, E. Styliaris)
• Instrumentation for Emission Tomography (small field γ-camera, Compton Camera, Optical tomography)
• Image Reconstruction Algorithms (iterative, stochastic)
• Simulations on the GEANT4/GATE environment
• Nuclear Structure, Reactions and Application Group (NuSTRAP, T. Mertzimekis)
• Nuclear Structure (shape coexistence, in exotic and stable nuclei, electromagnetic properties, symmetry, …)
• Nuclear Reactions (Reaction studies with stable & RIB, Nuclear Astrophysics/p-process, …)
• Instrumentation (detector developments for applied and fundamental research, sensors for marine radioactivity studies, …)

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NCSR “Demokritos”

• Unique accelerator facility for fundamental and applied research (neutron beams keV-25 MeV, ion beams, dedicated experimental setups for particle and γ-ray spectroscopy, state of the art XRF lab)
• Nuclear Physics group (S. Harissopulos, A. Lagoyannis, A. Karydas, M. Axiotis)
• Nuclear Astrophysics (p-process,...)
• Nuclear Reaction studies ((n,x), (p,x), (d,x),...)
• Nuclear Applications (IBA, NRA, RBS, XRF,...)
• Nuclear theory Group (D. Bonatsos)
• Shape/phase transitions and nuclear shape coexistence
• Symmetries in nuclear structure

AMS (U. Oxford, under installation)

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National Technical University of Athens

• Nuclear Physics Group (M. Kokkoris, M. Diakaki, R. Vlastou)
• Nuclear Reactions (IBA, NRA, …)
• Benchmarking and evaluation of nuclear reaction cross sections for IBA
• Neutron Physics (fission reaction studies, (n,xn), …)
• Instrumentation (detector developments for applied and fundamental research, …)
• Radiological studies in aquatic environment

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University of Ioannina

• Nuclear Physics Group (N. Patronis)
• Neutron physics (Fission reaction studies, (n,xn), (n,cp), …)
• Nuclear Astrophysics (s-process, p-process)
• Nuclear Structure (transfer and Coulex reaction studies at ISOLDE)
• Instrumentation (detector developments for fundamental research, …)
• Nuclear Applications (Ch. Papachristodoulou, K. Stamoulis)
• Radioecology, Radioprotection
• XRF lab (material characterization)
• Archeometry lab

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Aristotle University of Thessaloniki

• Nuclear Physics and Nuclear Applications group (A. Ioannidou, I. Savvides, S. Stoulos)
• Environmental radioactivity and radioprotection
• Nuclear Astrophysics
• Nuclear fission reaction studies
• γ-spectroscopy (characterization, detector development, in-situ spectroscopy,...)
• Nuclear theory group (Ch. Moustakidis, T. Gaitanos)
• Nuclear matter theoretical calculations (Nuclear Physics of neutron stars,...)
• Nuclear structure theoretical calculations

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HCMR

• Nuclear Marine applications group (Ch. Tsabaris. D. Patiris)
• Instrumentation for radiation measurements in marine environment
• Sea water radiation measurements and monitoring
• Radiation measurement and monitor in mineral and thermo-mineral springs
• Detection systems:
• KATERINA marine sensor (stability, continuous operation, operation in deep water, …)
• GeoMAREA marine sensor (autonomous mode of operation, self calibration, ohigh sensitivity, …)

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Distinctions and funding of the Hellenic Nuclear Physics Community

• Distinctions
• UoI: Prof. N. Patronis: n_TOF/CERN Physics Coordinator

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• National and European funding
• CALIBRA/3400 k€
• EU H2020 EIC Pathfinder RAMONES / 4000 k€
• EU Horizon Europe Widening “Nexus monARC” / 1500 k€
• HFRI (Scholarships & research funding)/(600+200 + 60) k€
• EU Horizon SANDA Project/ 3500 k€
• G4G -ESA/ 500 k€

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AMS (U. Oxford, under installation)

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The n_TOF facility

Is the “gluon” of the Greek Nuclear Physics Society:

• UoI and NTUA Nuclear Physics Groups are active and well involved members of the n_TOF collaboration
• AUTH members have already expressed interest to join
• Currently: >5 faculty members, 3 Post-docs, 4 PhD students, 4 MSc students, 4 BSc students
• Previous years: >7 PhD, >15 MSc thesis, …

Join forces for:

• Fission reaction studies (239Pu, 241Am, 230Th, …)
• (n,cp) reactions (medical applications, fusion technology, basic research)
• Nuclear astrophysics

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The n_TOF facility

Motivation:

High precision neutron induced cross section measurements for:

• Nuclear astrophysics
• ADS systems and G4 Fast neutron reactors
• Medical physics
• Basic research
• Fusion technology

140 researchers

40 research institutions/teams

20 PhD students/year

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The n_TOF facility: EAR1 + EAR2 + NEAR

NEAR

proton beam from the PS

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proton beam

N₂ gas cooling to avoid Pb corrosion and contamination of the cooling circuit

R Esposito et al. Phys. Rev. Accel. Beams 24, 093001 (2021)

3^rd generation target

The n_TOF facility

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The n_TOF facility

• EAR1: 8.6E5 n/pulse
• EAR2: 3.4E7 n/pulse
• NEAR: 9E8 n/cm²/pulse
• Pulse = 850E10 protons
• Max average proton intensity = 220E10 protons/s

The n_TOF facility

Neutron physics data for 11 orders of magnitude of neutron energies

The n_TOF facility: Is a unique neutron facility

Neutron physics data for 11 orders of magnitude of neutron energies

• neutron source instantaneous intensity and energy distribution
• repetition rate of the driver
• time (or neutron energy) resolution
• background conditions
• n_TOF is @ CERN: ISOLDE a few tenths meter away, …

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The n_TOF history in a nutshell

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The n_TOF (bright!) future

Short term

• Ready to launch new type of physics measurements ((n,n’), (n,xn), (n,cp), (n,tot), ...)
• Ready to go ahead with other applications (imaging, R2E, …)

Mid term

• Rabbit and gamma spectroscopy station (funding for Clover HPGe ensured)
• Moderator for NEAR beam

Long term

• Discussions for next (high power?) #4 n_TOF target (LS4)
• REAR station? (post LS4)
• …

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Conclusions

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• The Hellenic Nuclear Physics community is a continuously growing and dynamic community from the point of view of attracting young researchers and postgraduate students.
• Concerning Faculty/Researchers: A strong reduction in the number of permanent positions has occurred in the past ten years (hirings << retirements).
• The funding of Nuclear Physics Research is also significantly reduced.
• Research items within the Hellenic Nuclear Physics community:
• Fundamental research in nuclear structure and nuclear reaction mechanisms
• Applied nuclear physics research
• Nuclear theory
• NCSR “Demokritos” is the hub for the Greek Nuclear Physics Community offering training and hands-on involvement (especially in neutron beams) for younger colleagues and students. Dedicated and movable setups are there along with a variety of ion beams and different energies of neutron beams
• n_TOF/CERN brings together most of us in commοn projects and research actions. Synergies between Greek and Institutes abroad are continuously being sought and we are having success in strengthening/enriching the nuclear physics program in the framework of the n_TOF collaboration.

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Thank you so much for your attention!

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Extra Slides

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The NEAR station

The NEAR Station is the n_TOF facility’s new high-flux irradiation station.

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Two regions of activities

1. The irradiation area i-NEAR. Located next to the lead spallation target: high neutron dose material studies
2. The activation area a-NEAR. Located just outside the target bunker shielding, at only 3m distance from the target: nuclear astrophysics studies

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We can make integrated reaction rate measurements by shaping the neutron spectrum to look as close as possible to the stellar one

• The proof-of-principle study of shaping the n_TOF-NEAR neutron spectrum towards the extraction of stellar reaction rates was explored for the first time
• Boron carbide filters were used for the shaping the n_TOF - NEAR neutron spectrum
• Really promising results (!) showing that we can indeed obtain the stellar reaction rates even for the most challenging and unexplored physics cases

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Boron Carbide filters

Irradiation at NEAR

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ESA INTEGRAL mission detects 26Al γ-rays

Nuclear physics data are necessary in order to quantify the 26Al net yield: production – destruction:

²⁶Al(n,p/a) reactions are responsible for the destruction rate

•²⁶Al is a radioactive nucleus produced in massive stars

•The ²⁶Al half-life time (=720 thousand years) is still very small with respect to the age of Universe (=14 billion years).

•Each ²⁶Al nucleus decay produce one highly energetic γ-ray at 1.8 MeV. The interstellar medium is transparent to this ”light”

•By recording these γ-rays we have a ”snapshot” of on-going nucleosynthesis in our Galaxy. Accordingly, we can trace the dynamics of the Milky Way (rotational speed, expansion, chemical element production, etc)

•From the total production and destruction of ²⁶Al, we can understand how the cosmos chemical element factories (=stars) are producing energy and matter

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n_TOF: Understanding the ²⁶Al galactic snapshot

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^{Detector tests}

DDX:

Double-Differential Charged-Particle

detection setup for XS measurements from 20 to 200 MeV

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n beam

n beam

X17 detection setup:

• TPC
• LYSO
• Plastic

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Resolution function – setup

M. Bacak | n_TOF EAR1 | n_TOF CM

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30.05.2022

4x C6D6 detectors