Enhanced laser-driven ion sources for Firma convenzione nuclear and - - PowerPoint PPT Presentation

Firma convenzione Politecnico di Milano e Veneranda Fabbrica del Duomo di Milano

Aula Magna – Rettorato Mercoledì 27 maggio 2015

Enhanced laser-driven ion sources for nuclear and material science applications

Matteo Passoni Politecnico di Milano Nuclear Photonics, Brasov, 28/06/2018

Department of Energy

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❑ Largest university of engineering, architecture and design in Italy. ❑ More than 40000 students, ~1400 academic staff, 900 doctoral students ❑ 32 BSc, 34 MSc, 18 PhD programmes.

ERC consolidator grant: 5 year project, from September 2015 to September 2020 Principal investigator: Matteo Passoni

ERC-2014-CoG No.647554

Hosted @ , Department of Energy, Politecnico di Milano Goal: To Explore the New Science and engineering unveiled by Ultraintense, ultrashort Radiation interaction with mattEr Team: PI, 2 Associate Professor, 1 Assistant Professor, 3 Post-Docs, 3 PhDs + master students and support from NanoLab people

www.ensure.polimi.it

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The ENSURE team at Politecnico di Milano

ERC-POC INTER

Matteo Passoni Associate professor Margherita Zavelani Associate professor Andrea Pola Associate professor Luca Fedeli Post-doc Devid Dellasega Post-doc Valeria Russo Alessandro Maffini Post-doc Andrea Pazzaglia PhD student Arianna Formenti PhD student Francesco Mirani PhD student Francesca Arioli Master’s student

PI of ENSURE +

Assistant professor

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ENSURE: Main fields of research

Theoretical & experimental investigation

• f 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)

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Target is the key:

Conventional TNSA Enhanced TNSA

Ultra-short, super-intense laser pulse Ultra-short, super-intense laser pulse micrometric thick foil micrometric thick foil

Near-critical layer ❑ Near-critical layer onto a mm-thick foil

• M. Passoni et al. Phys Rev Acc Beams 19.6 (2016)

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Target is the key:

Hot electron cloud Hot electron cloud

Conventional TNSA Enhanced TNSA

Near-critical layer ❑ Near-critical layer onto a mm-thick foil ❑ More and hotter relativistic electrons

• M. Passoni et al. Phys Rev Acc Beams 19.6 (2016)

Conventional TNSA

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Target is the key:

Accelerated Ions Accelerated Ions

❑ Near-critical layer onto a mm-thick foil ❑ More and hotter relativistic electrons ❑ More ions at higher energy

Enhanced TNSA

Near-critical layer

• M. Passoni et al. Phys Rev Acc Beams 19.6 (2016)

The target is the key!

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Near-critical targets for laser-driven acceleration

Plasma critical density:

𝑜𝑑 = 𝜌 𝑛𝑓𝑑2 𝑓 l2

𝑜𝑑 ≈ 6 mg/cm3

(@ l=800 nm)

n>>nc overdense plasma

most of laser is reflected

n<<nc underdense plasma

little laser absorption

n ≈ nc near critical plasma strong laser-plasma coupling

Ilaser=1020 W/cm2 Elaser = 3 x 1011 V/m = 50 X Eatomic

Full ionization Plasma!

0.6 600 0.06

mg/cm3 ne/nc

0.1 1 10 100 0.01 6 60

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Ion acceleration @ PULSER (GIST)

in collaboration with: I. W. Choi, C. H. Nam et al.

5 10 15 20 25 30 10

1

10

2

10

3

10

4

10

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Counts [a.u.]

Energy (MeV)

bare Al 12 mm foam 8 mm foam

6 12 18 24 30 36 10 15 20 25 30

C

6+ maximum energy [MeV]

H

+ maximum energy [MeV]

Target thickness [mm]

H

+ max energy

C

6+ max energy

S polarization (peak intensity)

40 80 120 160

Role of target properties (s-pol, ~ 7 J, 3x1020 Wcm-2, 30° inc. angle) nearcritical foam thickness: Al (0.75 µm) + foam (6.8 mg/cm3, 0-36 µm)

❑ 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)

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0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5

5 10 15 20 25 30

Max proton energy [MeV] Intensity on target [10

20 W/cm 2] Al, p pol. Al, s pol. Al, c pol. foam, c pol. foam, p pol. foam, s pol.

0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5

5 10 15 20 25 30 35

Max proton energy [MeV] Intensity on target [10

20 W/cm 2] Al ( 0,75 mm) 8 mm foam 12 mm foam 18 mm foam 36 mm foam

Ion acceleration @ PULSER (GIST)

in collaboration with: I. W. Choi, C. H. Nam et al.

Role of pulse properties Al (0.75 µm) + foam (6.8 mg/cm3, 8 µm) pulse intensity pulse polarization: s, p and circular polarization ❑ strong for Al foils ❑ reduced for foam targets Dependence on polarization:

➢ foam vs Al: volume vs surface interaction ➢ irregular foam surface: polarization definition ➢ role of target nanostructure

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30 40 50 60 70 80 90 100 110 5 10 15 20 25 30

H

+ max. energy [MeV]

Laser power fraction (%) 4 mm C foam on 1.5 mm Al 1.5 mm Al, no foam

• F = 2.1 J/cm2
• P = 1000 Pa Ar
• dts= 4.5 cm
• Substrate = Al 1.5 µm
• Foam thickness = 4, 8, 12 µm

Laser parameters @ Draco (HZDR, Dresden)

Ion acceleration @ DRACO 150 TW

in collaboration with:

• I. Prencipe, T. Cowan, U. Schram et al.

2 4 6 8 10 12 5 10 15 20 25 30

H

+ max. energy [MeV]

Foam thickness [mm]

No foam

Foam PLD parameters

(preliminary data!)

• Energy on target = 2 J
• Intensity = up to 5 x 1020 W/cm2
• Angle of incidence = 2°

Optimal foam thickness

# Particles [1/(MeV*sr)] 5 10 15 20 25 30 Energy [MeV] 10¹⁰ 10¹¹ 10⁹ 10⁸ 10¹²

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Near-critical targets for laser-driven acceleration

Plasma critical density:

𝑜𝑑 = 𝜌 𝑛𝑓𝑑2 𝑓 l2

𝑜𝑑 ≈ 6 mg/cm3

(@ l=800 nm)

n>>nc overdense plasma

most of laser is reflected

n<<nc underdense plasma

little laser absorption

Gas-jets Solids

n ≈ nc near critical plasma strong laser-plasma coupling

Ilaser=1020 W/cm2 Elaser = 3 x 1011 V/m = 50 X Eatomic

Full ionization Plasma!

0.6 600 0.06

mg/cm3

C foams:

• ne
• f the (few)
• ptions

ne/nc

0.1 1 10 100 0.01 6 60

How to produce C foams: ns Pulsed Laser Deposition (PLD)

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Gas pressure Laser fluence

Substrate Plasma plume target-to-substrate distance Laser Beam Background Gas

• Inert (He, Ar..)
• Reactive (O2)

(almost any kind of substrate)

“atom by atom” deposition “Nanoparticle” deposition

Target l= 266, 532, 1064 nm Fluence: 0.1 - 20 J/cm2 Max rep. rate= 10 Hz Pulse duration= 7ns Energy= 0.1-2 J

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New experimental facilities @ Nanolab

fs-PLD interaction chamber Coherent Astrella ™

❑ Ti:Shappire l=800 nm ❑ Ep > 5 mJ ❑ Pulse duration < 100 fs ❑ Peak Power > 50 GW ❑ Rep Rate = 1000 Hz ❑ PLD mode + Laser processing ❑ up to 4 targets ❑ Upstream + downstream pressure control ❑ Fast substrate heater ❑ Fully automated software

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New experimental facilities @ 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

Combined fs-PLD & HiPIMS deposition techniques to fully control target preparation!

C-foam Substrate Laser Pulse fs-PLD HiPIMS

Foam property control with ns-PLD

Nano-scale Micro-scale Macro-scale

• Crystalline structure
• Composition
• Average density
• Morphology
• ….
• Uniformity
• Thickness profile

ns-PLD process parameters

Laser Wavelength Laser Fluence Gas pressure Geometry Deposition time

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How to produce carbon foams

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200 400 600 800 1000 10 100 1000

Density (mg/cm

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Pressure (Pa)

1.7 17.2 172.4

ne/nc

4 µm 4 µm 1 µm

l=532 nm F= 2.1 J/cm2 dT-S= 4.5 cm Foams nano-trees

• A. Zani et al., Carbon, 56 358 (2013)
• I. Prencipe et al., Sci. Technol. Adv. Mater. 16 (2015)
• A. Maffini et al., On the growth dynamics of

low-density carbon foams, in preparation

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

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Particle In Cell (PIC) Simulations

• With homogeneous foam
• With DLCCA foam

Inclusion of the nanostructure morphology to properly model physical processes Well established and powerful tool to study laser plasma interaction

• L. Fedeli et al. Scientific Reports, volume 8, Article number: 3834 (2018)

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A novel tool to study laser-driven ion sources for nuclear and material science

Integrated numerical simulation of laser-ion app

Monte Carlo simulation (Geant4) of Laser-Driven Ion Beam Analysis (IBA)

PIC simulation of laser-matter interaction DLCCA simulation of foam aggregation

• M. Passoni et al., Scientific Reports (2018), under review

Ca Fe Varnish Lead White HgS Concentration [%]

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Laser-driven Particle Induced X-ray Emission (PIXE)

Laser accelerated proton spectrum

2) X-ray spectra 3) Sample composition 1) Simulated experiment ❑ PIXE:

❑ Commercial codes not ok for laser PIXE

❑ Laser-driven PIXE:

✓ Unconventional features of ion beam (broad spectrum, tunable energy, ns bunch duration) ✓ Cheaper, portable PIXE setup

E [MeV] X-rays energy [keV]

Dedicated software to process x-ray data

Concentration [%] real retrived

✓ Ad-hoc code developed

Ion beam Particle Accelerator MeV energy, low current

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❑ 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

ERC-2016-PoC No.754916

INTER

Towards portable neutron sources

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Preliminary announcement of the 4th Targetry Workshop

ENSURE, ERC-2014-CoG No.647554

Monday 10th - Wednesday 12th, June 2019 Politecnico di Milano, Milano, Italy

Contact: matteo.passoni@polimi.it