Department of Energy. del Duomo di Milano. Matteo Passoni Politecnico di Milano

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1 Department of Energy Enhanced Firma laser-driven convenzione sources for Politecnico nuclear and di material Milano e science Veneranda applications Fabbrica del Duomo di Milano Matteo Passoni Politecnico di Milano Aula Magna Rettorato Mercoledì 27 maggio 2015 Nuclear Photonics, Brasov, 28/06/2018

2 Largest university of engineering, architecture and design in Italy. More than students, ~1400 academic staff, 900 doctoral students 32 BSc, 34 MSc, 18 PhD programmes. 2

3 ERC-2014-CoG No ERC consolidator grant: 5 year project, from September 2015 to September 2020 Goal: To Explore the New Science and engineering unveiled by Ultraintense, ultrashort Radiation interaction with matter Department of Energy, Politecnico di Milano Principal investigator: Matteo Passoni Team: PI, 2 Associate Professor, 1 Assistant Professor, 3 Post-Docs, 3 PhDs + master students and support from NanoLab people 3

4 The ENSURE team at Politecnico di Milano Matteo Passoni Associate professor PI of ENSURE + ERC-POC INTER Margherita Zavelani Associate professor Andrea Pola Associate professor Valeria Russo Assistant professor Luca Fedeli Post-doc Devid Dellasega Post-doc Alessandro Maffini Post-doc Andrea Pazzaglia PhD student Arianna Formenti PhD student Francesco Mirani PhD student Francesca Arioli Master s student 4

5 ENSURE: Main fields of research Theoretical & experimental investigation of laser-driven ion acceleration Advanced target production (low-density foams & multilayer targets) for laser-plasma interaction experiments Application of laser-driven ion acceleration in material & nuclear fields (e.g. Compact neutron sources, Laser-driven Ion Beam Analysis) 5

6 Target is the key: Near-critical layer Ultra-short, super-intense laser pulse Ultra-short, super-intense laser pulse micrometric thick foil micrometric thick foil Conventional TNSA Enhanced TNSA Near-critical layer onto a mm-thick foil M. Passoni et al. Phys Rev Acc Beams 19.6 (2016) 6

7 Target is the key: Hot electron cloud Near-critical layer Hot electron cloud Conventional TNSA Enhanced TNSA Near-critical layer onto a mm-thick foil More and hotter relativistic electrons M. Passoni et al. Phys Rev Acc Beams 19.6 (2016) 7

8 Target is the key: Near-critical layer Accelerated Ions Accelerated Ions Conventional TNSA Enhanced TNSA The target is the key! M. Passoni et al. Phys Rev Acc Beams 19.6 (2016) Near-critical layer onto a mm-thick foil More and hotter relativistic electrons More ions at higher energy 8

9 Near-critical targets for laser-driven acceleration I laser =10 20 W/cm 2 E laser = 3 x V/m = 50 X E atomic Full ionization Plasma! Plasma critical density: n c = π m ec 2 n c 6 mg/cm 3 e l 2 (@ l=800 nm) n n c near critical plasma strong laser-plasma coupling n<<n c underdense plasma n>>n c overdense plasma little laser absorption most of laser is reflected n e /n c mg/cm 3 9

10 H + maximum energy [MeV] C 6+ maximum energy [MeV] Counts [a.u.] Ion PULSER (GIST) in collaboration with: I. W. Choi, C. H. Nam et al. Role of target properties (s-pol, ~ 7 J, 3x10 20 Wcm -2, 30 inc. angle) nearcritical foam thickness: Al (0.75 µm) + foam (6.8 mg/cm 3, 0-36 µm) H + max energy C 6+ max energy bare Al 12 mm foam 8 mm foam 10 S polarization (peak intensity) Target thickness [mm] Energy (MeV) There is an optimum in near critical layer thickness Maximum proton energy enhanced by a factor ~ 1.7 Number of proton enhanced by a factor ~ 7 M. Passoni et al., Phys. Rev. Accel. Beams 19, (2016) I. Prencipe et al., Plasma Phys. Control. Fus. 58 (2016) 10

11 Max proton energy [MeV] Ion PULSER (GIST) Max proton energy [MeV] in collaboration with: I. W. Choi, C. H. Nam et al. Role of pulse properties Al (0.75 µm) + foam (6.8 mg/cm 3, 8 µm) pulse intensity pulse polarization: s, p and circular polarization 30 Al, p pol. 35 Al ( 0,75 mm) Al, s pol. Al, c pol. foam, c pol. foam, p pol. foam, s pol mm foam 12 mm foam 18 mm foam 36 mm foam ,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 Intensity on target [10 20 W/cm 2 ] Intensity on target [10 20 W/cm 2 ] Dependence on polarization: strong for Al foils reduced for foam targets foam vs Al: volume vs surface interaction irregular foam surface: polarization definition role of target nanostructure 11

12 H + max. energy [MeV] H + max. energy [MeV] # Particles [1/(MeV*sr)] Ion DRACO 150 TW (preliminary data!) Laser Draco (HZDR, Dresden) 30 Energy on target = 2 J Intensity = up to 5 x W/cm 2 Angle of incidence = 2 Foam PLD parameters F = 2.1 J/cm 2 P = 1000 Pa Ar d ts = 4.5 cm Substrate = Al 1.5 µm Foam thickness = 4, 8, 12 µm ¹² in collaboration with: I. Prencipe, T. Cowan, U. Schram et al. 4 mm C foam on 1.5 mm Al 1.5 mm Al, no foam Laser power fraction (%) 25 Optimal foam thickness 10¹¹ ¹⁰ 10 No foam 10⁹ Foam thickness [mm] 10⁸ Energy [MeV] 12

13 Near-critical targets for laser-driven acceleration I laser =10 20 W/cm 2 E laser = 3 x V/m = 50 X E atomic Full ionization Plasma! Plasma critical density: n c = π m ec 2 n c 6 mg/cm 3 e l 2 (@ l=800 nm) n n c near critical plasma strong laser-plasma coupling n<<n c underdense plasma n>>n c overdense plasma little laser absorption most of laser is reflected n e /n c 0.06 Gas-jets C foams: one of the (few) options Solids mg/cm 3 13

14 How to produce C foams: ns Pulsed Laser Deposition (PLD) Target Plasma plume Laser Beam l= 266, 532, 1064 nm Pulse duration= 7ns Energy= J Fluence: J/cm 2 Max rep. rate= 10 Hz target-to-substrate distance Laser fluence Substrate (almost any kind of substrate) Background Gas Inert (He, Ar..) Reactive (O 2 ) Gas pressure atom by atom deposition Nanoparticle deposition 14

15 New experimental Nanolab fs-pld interaction chamber PLD mode + Laser processing up to 4 targets Upstream + downstream pressure control Fast substrate heater Fully automated software Coherent Astrella Ti:Shappire l=800 nm Ep > 5 mj Pulse duration < 100 fs Peak Power > 50 GW Rep Rate = 1000 Hz 15

16 New experimental Nanolab High Power Impulse Magnetron Sputtering (HiPIMS): Peak power density = 10³ W/cm² Peak current density = 1 10 A/cm² Two cathodes, multi-elemental targets Fully automated software Laser Pulse Combined fs-pld & HiPIMS deposition techniques to fully control target preparation! fs-pld HiPIMS C-foam Substrate 16

17 Foam property control with ns-pld Nano-scale Micro-scale Macro-scale - Crystalline structure - Composition - Average density - Morphology -. - Uniformity - Thickness profile Laser Wavelength Laser Fluence Gas pressure Geometry Deposition time ns-pld process parameters 17

18 Density (mg/cm 3 ) How to produce carbon foams µm l=532 nm F= 2.1 J/cm 2 d T-S = 4.5 cm nano-trees 4 µm 17.2 n e /n c 4 µm 10 Foams 1.7 A. Zani et al., Carbon, (2013) I. Prencipe et al., Sci. Technol. Adv. Mater. 16 (2015) Pressure (Pa) A. Maffini et al., On the growth dynamics of low-density carbon foams, in preparation 18

19 Aggregation model to study the foam growth Diffusion-Limited Cluster-Cluster Aggregation (DLCCA): 1) Brownian motion of particles 2) Particle aggregation in clusters by irreversible sticking 3) Clusters deposition on substrate Real Foam Simulated Foam 19

20 Particle In Cell (PIC) Simulations Well established and powerful tool to study laser plasma interaction Inclusion of the nanostructure morphology to properly model physical processes With homogeneous foam With DLCCA foam L. Fedeli et al. Scientific Reports, volume 8, Article number: 3834 (2018) 20

21 Integrated numerical simulation of laser-ion app A novel tool to study laser-driven ion sources for nuclear and material science DLCCA simulation of foam aggregation Monte Carlo simulation (Geant4) of Laser-Driven Ion Beam Analysis (IBA) PIC simulation of laser-matter interaction M. Passoni et al., Scientific Reports (2018), under review 21

22 Laser-driven Particle Induced X-ray Emission (PIXE) PIXE: Particle Accelerator MeV energy, low current Ion beam Laser accelerated proton spectrum 1) Simulated experiment Laser-driven PIXE: Unconventional features of ion beam (broad spectrum, tunable energy, ns bunch duration) Cheaper, portable PIXE setup Commercial codes not ok for laser PIXE Ad-hoc code developed 2) X-ray spectra E [MeV] Concentration [%] real retrived 3) Sample composition Concentration [%] Varnish Lead White X-rays energy [kev] Dedicated software to process x-ray data Ca Fe HgS 22

23 Towards portable neutron sources ERC-2016-PoC No INTER Compact neutron sources for material characterization fast-neutron spectroscopy neutron radiography Preliminary studies with coupled PIC - Monte Carlo simulations Strong collaboration with industrial partners See Maffini (P39), Mirani (P46) posters! A. Tentori, MSc thesis in Nuclear Engineering (2018) F. Arioli, MSc in Nuclear Engineering, in preparation 23

24 Preliminary announcement of the 4 th Targetry Workshop Monday 10 th - Wednesday 12 th, June 2019 Politecnico di Milano, Milano, Italy Contact: matteo.passoni@polimi.it ENSURE, ERC-2014-CoG No