Laboratory Astrophysics Working Group Summary, Summaries of Astrophysics

Download Laboratory Astrophysics Working Group Summary and more Summaries Astrophysics in PDF only on Docsity! Laboratory Astrophysics Working Group Summary Pisin Chen Stanford Linear Accelerator Center Stanford University • Introduction • Calibration of Observations • Investigation of Dynamics • Probing Fundamental Physics • Summary SABER Workshop March 15-16, 2006, SLAC LabAstro WG Participants P. Chen (KIPAC) (Chair) C.-W. Chen (KIPAC/NTU) (Scientific Secretary) C.-C. Chen (KIPAC/NTU) (Scientific Secretary) E. do Couto e Silva (KIPAC) C. Field (SLAC) R. Fiorito (UMD) Wei Gai (ANL) J. S.-T. Ng (KIPAC) R. Noble (SLAC) C. Pellegrini (UCLA) K. Reil (KIPAC) B. Remongton (LLNL) P. Sokolsky (Utah) A. Spitkovsky (KIPAC) D. Walz (SLAC) G. Barbiellini (Rome) (in absentee) Three Categories of LabAstro -Using Lasers and Particle Beams as Tools - 1. Calibration of observations - Precision measurements to calibrate observation processes - Development of novel approaches to astro-experimentation Impact on astrophysics is most direct 2. Investigation of dynamics - Experiments can model environments not previously accessible in terrestrial conditions - Many magneto-hydrodynamic and plasma processes scalable by extrapolation Value lies in validation of astrophysical models 3. Probing fundamental physics - Surprisingly, issues like quantum gravity, large extra dimensions, and spacetime granularities can be investigated through creative approaches using high intensity/density beams Potential returns to science are most significant 1. Calibration of Observations Some Thoughts on Laboratory Astrophysics for UHE Cosmic Rays Pierre Sokolsky University of Utah SABRE Workshop SLAC, March, 2006 Are there other such? • Follow-up on FLASH - increase precision, effects of impurities • ANITA radio detection efficiency tests • Validation of low energy electromagnetic shower codes at large Moliere radii. • Atmospheric EAS radio detection - what is the balance of Askaryan vs Earth’s magnetic field effects? - Possible controlled experiment producing shower in dense material with B field? Radio signals from EAS in Air • Mechanism is Askarian + curvature of charged particles in Earth’s B field (coherent geosynchrotron radiation). • Exact balance not well known • First convincing demonstration by French and German groups (LOPES with Kascade-Grande, CODALEMA) - coincidence with particle ground arrays. • May be the next big step?? Issues, continued • Low energy shower modeling validation - GEANT, FLUKA predictions for e, gamma and hadron subshowers - very significant for understanding muon content of EAS, even at EHE • High energy interaction models - pp cross-section, p-air cross section - pion and kaon multiplicities, forward direction physics - important for Xmax composition measurement ESTA: End Station Test of ANITA SLAC-ANITA Collaboration Expected date: June 2006 2. Investigation of Dynamics Relativistic Collisionless Shocks: Shock Structure and Particle Acceleration Anatoly Spitkovsky (KIPAC, Stanford) Shocks in astrophysics: expectations of composition, structure and FS se] eee eer et easy Sam 3D shock modeling -- simulation setup TB sPTee ree fated ct6 ct g@1 ec eom neal 2 | ae) ed BT) UT (e in erae=1 eos ee ler som ers) mee on] Fh =e 018 ee el b) Oblique Shocks in electron-ion plasma Fs) ee |] e Pd -26 | mele 0 Pd 6| Conclusions Shock structure o=0.1 eee ee 3D density ale ae fe ae br Shock is clearly magnetized -- anisotropy with respect to B. Shock acceleration failure Is it the injection problem? Perhaps high-energy preaccelerated particles will have : i —_ easier time crossing the shock? i Ly a — a acl 1 ana In order to outrun a moving shock, need eee ee ee ne ae fi a coy Pet aes Shock stirfing without Glectiastatic trap will only work in nonrelativistic shocks! Can we constrain GRB shock parameters using the Gamma Ray Large Area Space Telescope? Eduardo do Couto e Silva SLAC/KIPAC SABER Workshop – Mar 15, 2006 Back to the Main Questions • Is there any connection between the SABER program and the physics interests of GLAST? – Can we simulate in the laboratory an environment similar to that of the shock dissipation phase in GRBs? – Can we quantify the relative importance of magnetic fields during the shock dissipation phase in GRBs? – A deeper question: • Are B fields generated locally or at the central engine? Simulation of Relativistic Jet-Plasma Interactions Johnny Ng and Bob Noble Stanford Linear Accelerator Center SABER Workshop, Laboratory Astrophysics WG SLAC, March 15-16, 2006 Issues and Questions What are the plasma microphysics that cause particle acceleration and deceleration, and radiation in jet- plasma interactions? What are the parameters for scaled lab experiments that can explore this physics, benchmark the codes, and connect this plasma physics to the astrophysical observations? Real astrophysical outflows are larger than anything we can simulate with a PIC code. We focus on the physics at the plasma wavelength scale. Summary of Simulation Results 1. General results: We observe the correct (n/γ)1/2 scaling of the Weibel instability growth rate, transverse filament size of few skin depths, and approximately the correct absolute growth rate. Neutral jets in unmagnetized plasmas are remarkably unstable. One expects stability to improve if a background longitudinal B field existed. 2. Plasma filamentation sets up the jet for other instabilities. Separation of electron and positron filaments. Separating positron filaments generate large local EZ Charge filaments excite longitudinal electrostatic plasma waves We observe two local acceleration mechanisms: Inductive “Faraday acceleration” Electrostatic Plasma Wakefield acceleration. Robust general result: only requires Weibel filamentation Acceleration in Relativistic Jet- Plasma Interactions at SABER Johnny S.T. Ng Stanford Linear Accelerator Center Stanford University SABER Workshop, March 15-16, 2006, SLAC. Cosmic Acceleration at SABER • Create a relativistic electron-positron plasma “jet” by showering a high energy beam in solid target • Investigate acceleration mechanisms in jet-plasma interactions over a scale of tens of collisionless skin- depths • Current simulation techniques can accurately resolve physics on this scale (see Bob Noble’s talk) Applicable to astronomical collisionless plasmas Important tests of our ability to simulate these effects in astronomical environments General Requirements for Jet-plasma Experiment at SABER • Beam: – Energy above 10 GeV – Ne = 2 to 4 x 1010 – Size: σxy = 10 to 50 μm, σz = 40 μm – Energy density ~ 1016 J/m3 ! • Facility infrastructure: – Radiation shielding: 6 to 7 Xrad target – Space to mount experiment: 4 m by 10 m – Beam line diagnostics (toroids, BPM, OTR) • Beam time: – Program will last 3 to 5 years – 3-week runs, total 2 months per year Measurement Parameters • Filamentation: – Image jet down stream; micron resolution required – Magnetic field diagnostics based on Faraday rotation: sensitivity? Electron and positron filaments cancellation? • Acceleration: – Electron and positron energy spectrum • Radiation: – Spectra and angular dependence Summary SABER is unique: high-energy-density beams providing relativistic plasma jets “To understand the acceleration mechanisms of these [UHECR] particles, a better understanding of relativistic plasmas is needed” “Laboratory work [thus] will help to guide the development of a theory of cosmic accelerators, as well as to refine our understanding of other astrophysical phenomena that involve relativistic plasmas.” Turner Committee on the Physics of the Universe: “Eleven Science QuestionsFor the New Century”, NRC, 2003 oy] Z PF aa - ae I Op reet a Secreta ae alee 2--—-— 40 60 80 100 20 3 6 40 60 80 400 20  “46, 10 7000 7000 1.1 €.08.00.1 04.0 9200 600 17 ION EO 76,90 TODO 7000 7.1 £.01.00.1 0406 200.600 12 1900 20K 0.400 Gamma-Ray Bursts in laboratory (Ta Phuoc et al. 2005) Laser Pulse tlaser = 3 10-14 s Laser Energy = 1 Joule Gas Surface = 0.01 mm2 Gas Volume Density = 1019 cm-3 Power Surface Density σW= 3 1018 W cm-2 WakeField Acceleration SABER proposal • Proposal for SABER – Create a pulsed beam to very scaling relations of density – not focused on a particular model – Measure the X-ray spectrum vs the density of the plasma. • Experimental Set-up (beam parameters) – Laser Pulse tlaser – 3 10-14 s – Laser Energy Science outreach on NIF: possibilities for astrophysics experiments Presentation to the SABER workshop, Stanford Linear Accelerator Center, March 15-16, 2006 Bruce A. Remington Group Leader, HED Program Lawrence Livermore National Laboratory Highlights from HEDLA-06 Presentation to the SABER workshop, Stanford Linear Accelerator Center, March 15-16, 2006 Bruce A. Remington HED Program Lawrence Livermore National Laboratory High energy density (HED) implies large Energy/Volume, which is the prevailing condition in high energy astrophysics Log ρ(g/cm3) L og T (K ) L og k T (e V ) Log n(H)(/m3) [NRC X-Games report, R. Davidson et al. (2003)] Peter Celliers: EOS of dense He showing reflectivities, 5% ionization thermally generated Ray Smith: ICE drive on laser to 2 Mbar at Omega along a quasi-isentrope Jonathan Fortney, Gilles Chabrier: planetary interior structure sensitive to EOS models, experiments Jim Hawreliak: dynamic diffraction of shocked Fe showing α−ε transition at 120 kbar in sub-nsec Barukh Yaakobi: dynamic EXAFS of shocked Fe showing α−ε transition at 120 kbar in sub-nsec Marcus Knudson: EOS of water, showing refreeze (Dan Dolan) Michel Koenig: absolute EOS msmt capability for Al, using Kα radiography Tomek Plewa: “solved” the core-collapse SN1987A problem? Carolyn Kuranz: deep nonlinear Omega experiments relevant to SN1987A Lebedev, You, Kato: magnetic tower jets on Z-pinch, Cal Tech plasma simul. chamber, astrophys. Marc Pound: synthetic observations of Eagle Nebula models to compare with actual observations Amy Reighard: ρ/ρ0 = 50 in radiative shock in Xe gas at Omega laser Freddy Hansen: radiative shock precursor launches new shock Gianluca Gregori: XTS to get Te, Ti, ne, Z in HDM and WDM Steve Rose: photoionized plasmas (of Fe): models that put in all the levels poorly better than models that put in only some of the levels well (leaving out others). Showed Z distribution (Au, Fe) vs exp’ldata, w/, w/o rad. and/or dielectronic recomb/autoioniz Jim Bailey: exp’l opacity of Fe at conditions approaching those of the solar radiative zone Scott Wilks: PW experiments to reach high temperatures (200-300 eV) in solid-density Cu targets Sebastien Le Pape, B = 500 MG using proton deflectometery Karl Krushelnick: B = 750 MG using high harmonics cutoffl; speculation of reconnection signature Dmitri Ryutov, John Castor, Gordienko: scaling in collisionless, intense laser experiments regime Mikhail Medvedev: Weibel instability in GRB models and in intense laser experiments Richard Klein: proposed NIF astro. exp. to achieve Te = 5 keV in (1mm)3 solid density Anatoly Spitkovsky: pulsar winds and wind shocks Some highlights from HEDLA06 Cosmic Particle Aceleration “How do cosmic accelerators work and what are they accelerating?” • Generally agreed by the LabAstro WG as the best niche of SABER in contributing to Laboratory Astrophysics in the “astro-dynamics” category. • Most appropriately by way of jet-dynamics studies. Weibel instabilities - GRB people JNg et al moving forward with this. Saber - a lot of different kinds of jets e+e- - other models - single component models Differentiate different models. Differentiatability vs plausability Prioritize - users have to do this Techinical issues - different jet types - different location, etc e-p+ jets Astro-Jet Dynamics • Laser and/or e-beam probe • e-p+ jets? • Softer beams allow more things • e164-e167 diagnostics exist.... Are they available for use? • Are the developed diagnostics going to be generally available tools? Issues Related to SABER