Ion acceleration and nuclear physics with 10 PW lasers. Paul McKenna University of Strathclyde

Transcription

1 Ion acceleration and nuclear physics with 10 PW lasers Paul McKenna University of Strathclyde

2 Talk summary 1. Nuclear activation applied as a diagnostic of laser-plasmas 2. Laser-driven ion acceleration: present and future prospects 3. Nuclear physics with 10 PW pulses SCAPA project in Scotland

3 Laser-driven nuclear reactions: (p,n) for medical isotope production Courtesy of H. Schwoerer, Jena See for example: Ledingham, McKenna & Singhal, Science (2003)

4 Photo-nuclear activation as a plasma diagnostic The ratio of the numbers of two different nuclear reactions induced can be used to measure the photon temperature N N ( γ, n) ( γ,3n) = σ σ γ, n γ,3n ( E) n γ ( E) n γ ( E)dE ( E)dE Spencer et al NIM 2000 Schwoerer et al Photo-nuclear activation also used to measure angular distribution of gammas (and therefore electrons) e.g. Santala et al PRL 2001

5 Number of protons ( / MeV) Nuclear activation measurements of ion beam properties Protons, ions Vulcan pulse foil Rear Front Protons, ions C sample Proton energy (MeV) Cu stack Number of irradiated nuclei N / N = 0 σ ( E) nγ ( E, T ) de E th Ag activation Dosimetry film 14 MeV 18 MeV McKenna et al., Phys. Rev. Lett., 91, (2003) McKenna et al., Appl. Phys. Lett., 83, 2763 (2003) McKenna et al., Phys. Rev. E, 70, (2004) Yang et al., App. Phys. Lett., 84, 675 (2004) Clarke et al., NIMA 585, 117 (2008)

6 Talk summary 1. Nuclear activation applied as a diagnostic of laser-plasmas 2. Laser-driven ion acceleration: present and future prospects 3. Nuclear physics with 10 PW pulses SCAPA project in Scotland

7 Ion acceleration by TNSA Preplasma Thin H 2 O layers Ponderomotive electron acceleration Target Normal Sheath Acceleration Plasma expansion Electron sheath Ions E~TV/m μm Properties: Maximum energy: protons ~65 MeV; ions ~10 MeV/u; High brightness: >10 12 protons in ps pulse Source size ~100 μm; (virtual source ~10 μm); Emittance ε N ~0.005π mm.mrad Energy conversion efficiency up to 10%

8 Laser-accelerated protons: present and future performance ASTRA GEMINI 2x20 J, 30 fs RAL 10 PW 300J, 30fs (2013) experiments 300fs 1 ps fs fs simulations Nova PW RAL Vulcan RAL RAL Vulcan RAL LULI PW Janusp Osaka CUOS Vulcan LOA 3rd ampli ELI 10 beamlines 1 Tokyo Yokohama MPQ Tokyo ASTRA Tokyo Iλ 2 (W.cm -2.µm ) Courtesy of M. Borghesi: See Borghesi et al, PFCF 49, 416 (2006)

9 Radiation pressure acceleration of ions Stage 1 Laser field sweep away all electrons, forming an electrostatic field To produce 1 GeV protons in τ = 1 laser period we need I ~ W/cm 2. Ions pulled by the charge separation field move together with electrons. Stage 2 Plasma forms a mirror accelerated by the laser field radiation pressure. The difference between the incident and reflected wave energy is taken by the mirror: 2 E EL E L ( γ ) Δ % 2 ( γ ) ΔEion EL EL Because m e <<m i almost all energy transfers to ions: T. Esirkepov, M. Borghesi, S. V. Bulanov, et al., PRL 92, (2004).

10 Light-Sail RPA 2D OSIRIS PIC simulations performed by C. Bellei, Imperial College and A.P.L.Robinson, RAL Cyrogenic H target, density = 40 n cr I L = 1.25x10 23 Wcm -2, t L =25 fs Relativistic ion energies obtained (p up to 2.5 GeV, C 6+ up to 1 GeV/u)

11 Ion beams with 10 PW laser pulses Assuming intensity ~10 23 Wcm -2 (i.e. f/1 focusing) TNSA: MeV/u RPA: >GeV/u, narrow energy band and high flux Ions from underdense plasmas: ~100 MeV/u

12 Vulcan 10 PW project in the U.K. Seed laser mj Level Source Ps, mj Pump Additional Vulcan 2 x 1.2 kj 3 ns 208 beam lines PHASE 1nd-Front End 3ns, 4J shaped pulsed pump, 2 Hz J Level OPCPA Amplifier LBO Seed Long Stretch ~3ns LBO LBO λ ~ 900 nm 527 nm SHG SHG 527 nm Seed E=1J 600 J 600 J Phase 2 KD*P KD*P kj Level OPCPA Amplifier New Interaction Area Interaction Chamber 300 J, fs 30 fs + LP Beam lines Based on a combination of LBO and KD*P 1 shot every ~10 minutes 3 stages of amplification High contrast source Courtesy of Cristina Hernandez-Gomez, RAL - >500 J Compress Interaction Chamber 300 J, 30 fs + 1 PW Beam line Existing TAP Interaction Area EXISTING VULCAN

13 Vulcan 10 PW Facility Existing TAP 1 PW + 10 PW area Existing Target Area Petawatt (TAP) Deliver the new 10 PW into this area Configured with the current PW capability Long focal length option (F 20) ELECTRON DUMP AREA Existing LASER AREA NEW LASER ROOM LA5 NEW PULSED POWER AREA CAPACITOR ROOM TARGET AREA WEST TARGET AREA CONTROL ROOM High Intensity Target Area 10PW High Intensity Area (HIA) Fully Shielded area inc roof Configured with existing (upgradeable) 1.8 kj beamlines

14 Second Floor OPCPA AMPLIFICATION COMPRESSOR AND DIAGNOSTICS AREA OPCPA LONG PULSE AMPLFICATION AREA LASER CONTROL ROOM OPCPA FRONT END ROOM

15 Talk summary 1. Nuclear activation applied as a diagnostic of laser-plasmas 2. Laser-driven ion acceleration: present and future prospects 3. Nuclear physics with 10 PW pulses SCAPA project in Scotland

16 Ideas for ELI ( photo- ) nuclear physics 10 PW Intensity ~10 23 W/cm 2 E-field ~10 16 V/m + γ-ray Electron Recovery Linac (Compton scatt.)? Nuclear activation as a diagnostic / particle source GeV electrons and gammas GeV protons/ions (fission, spallation etc) secondary neutrons, pions, muons, neutrinos.. Laser assisted nuclear physics field-induced phenomena eg 100 ev shifts in nuclear levels change the decay schemes; effects of electron screening etc NEEC: Nuclear excitation by electronic capture Photo-nuclear physics Monoenergetic, brilliant, pulsed gamma rays e.g. Compton backscattering nuclear resonance fluorescence photo-hadron reactions

17 Proton induced activation diagnostic development High energy threshold reactions: Fission; Spallation; Pion production (and by decay, muons and neutrinos Pair production Relativistic electrons can produce electron-positron pairs via the Bethe- Heitler and trident processes when interacting with high-z ions.

18 Neutron production with GeV ions Assuming ~ GeV protons >10 12 neutrons in s by spallation Use of brilliant γ beams what neutron flux can be expected by (γ,n) reactions? How does the neutron flux compare? Aside: Fast Ignition shot would produce 30 MJ of energy 22 MJ of 14 MeV neutrons (10 19 in sec) Isotropic distribution

19 Production of neutron-rich nuclei Investigations of neutron-rich nuclei enabled e.g. by acceleration of radioactive ions? - investigation of branching points, exotic nuclei near drip line..?

20 Compton gamma-rays driven by RPA? RPA to produce a flying high density electron bunch (>10 22 cm -3 ) Scattered photons are up shifted by 4γ 2 (need γ>1000 for MeV) Coherent narrow band gammas in attosecond pulses?? incident pulse reflected pulse Requires: Ultrahigh laser pulse contrast; High intensity >10 23 Wcm -2 ; Ultrathin targets (few nanometer). Issues: Can a good quality relativistic mirror be maintained? Is a simple narrow-band upconversion likely?

21 Summary GeV ions may be possible using 10 PW laser pulses using radiation pressure drive (few 100 MeV by TNSA) Requires ultrahigh contrast! Unique points regarding laser as a nuclear physics driver: Acceleration at high densities Ultrashort pulses possible Synchronised pulses from same driver: pump-probe ELI (photo-)nuclear pillar could combine: 3x10 PW laser (ions, secondary particles, high fields, activation etc) with γ-ray ERL (coherent, tunable monoenergetic γ beam, resonance fluorescence, nuclear probe)

22 Talk summary 1. Nuclear activation applied as a diagnostic of laser-plasmas 2. Laser-driven ion acceleration present and future prospects 3. Nuclear physics with 10 PW pulses SCAPA project in Scotland

23 Nuclear & Plasma Physics The Scottish Centre for the Application of Plasma based Accelerators SCAPA Prof Dino Jaroszynski University of Strathclyde, UK 23

24 Nuclear & Plasma Physics Creation of a Scottish Centre of Excellence for laser-plasma based radiation sources producing Ultra-short duration X-ray pulses Coherent EM radiation Gamma rays Protons & light ions and their applications in Electron and X-ray diffraction Particle detector development Radiation damage in nuclear fusion reactors (ITER, HiPER) Nuclear physics and QED (ELI, HiPER) Condensed matter physics New concepts in energy generation (fission and fusion) Molecular biology and medicine 24

25 ALPHA-X started in 2002: Advanced Laser Plasma High-energy Accelerators towards X-rays Compact femtosecond duration synchrotron, free-electron laser and gamma ray source λ = 2.8 nm 1 μm (<1GeV beam) electron bunch duration: several fs electron beam spectrum No. electrons / MeV [a.u.] (b) σ γ γ < 0.7% Electron energy [MeV] (a) beam emittance: several π mm mrad Brilliant particle source: 10 MeV GeV, ka peak current, fs duration FEL

26 TOPS laser: 1 10 Hz λ = 800 nm LASER IN 30 fs Existing ALPHA-X beam line PLASMA ACCELERATOR ELECTRON ENERGY SPECTROMETER UNDULATOR BENDING MAGNET RADIATION SPECTROMETER m

27 SCAPA Scottish Centre for the Application of Plasma-based Accelerators Challenges Replace light source ALPHA-X: Ti:sapphire laser 10 Hz, 800 nm SCAPA: 1 J 5-10 J, 30 fs, 30 TW TW Increase Electron energy (> 1 GeV) Photon energy (> 1 kev) Peak brilliance and coherence (FEL) Decrease Electron pulse length 10 fs < 1 fs Setup accelerator lab for Electrons Photons Ions Coherent radiation Setup applications programme 27

28 28 New lab layout

29 SUPA: Nuclear & Plasma Physics SCAPA participants Plasma physics Dundee, Glasgow, Heriot-Watt, West of Scotland, Strathclyde Univ. Nuclear physics Edinburgh, Glasgow, West of Scotland, Strathclyde Collaborations SUPA Condensed matter physics, particle physics, PALS Scotland SULSA, ScotChem, Engineering UK CLF, RAL, DL/Cockcroft Inst., Universities Internationally ITER, HiPER, FAIR, ELI EU FP6 & FP7 (HadronPhysics, Laserlab-Europe) National Labs in Europe and North America Universities in Europe, USA, Asia 29

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31 Importance of ultrahigh contrast P. McKenna et al, LPB (2008) D.C. Carroll et al, CRP (2009) 40 7 Maximum proton energy (MeV) I abl Δt Energy conversion efficiency (%) I abl Δt Scale length, L O (μm) Scale length, L O (μm) Proton measurements show that controlled preplasma expansion leads to enhanced energy coupling to fast electrons

32 Synergy with nuclear diagnostics of fusion plasmas ELI will drive nuclear diagnostic capability to higher energy and density systems; Higher nuclear yields expected; observation of lower cross section and higher threshold energy reactions; Development of detectors to withstand harsh plasma environment Innovative nuclear diagnostics required for fusion plasmas Examples: fusion reaction history measurements (D + T γ+ 5 He); charged particle detection to measure yield of neutron-less reactions (e.g. D + 3 He p (15 MeV) + 4 He); Techniques for combining imaging and spectral measurements of fast neutrons;