From elementary processes From elementary processes to plasma - PowerPoint PPT Presentation

olytechnic of Bari, Italy Institute of Nanot CNR - Bari, Ital From elementary processes From elementary processes to plasma modeling to plasma modeling Roberto Celiberto Roberto Celiberto 1 st Research Coordination Meeting on Atomic Data for Vapour Shielding in Fusion Devices I.A.E.A. Vienna, March 2019

Non-equilibrium low-temperature plasmas Molecular plasmas Non-Boltzmann population Non-Maxwellian electron energy distributions function State-to-state vibrational kinetics Large sets of cross section data

Vibrational kinetics of electronically excited states in H 2 discharges Colonna et al., Eur. Phys. J. D (2017) The evolution of atmospheric pressure hydrogen plasma under the action of repetitively ns electrical pulse

Input data =============================================== E m /N = 200 Td ; Pulse = 20 ns ; Gas temperature = 1000 K Gas pressure = 1 bar. Molar fractions: χ = χ = − 10 10 + e H 2 χ = ⋅ − 9 2 10 H χ = χ = χ = 0 + − + H H H 3 ===============================================

H 2 /H STATE-TO-STATE KINETICS Ground state vibrational kinetics Ground state vibrational kinetics Atomic level kinetics Electron impact induced processes Molecular ion kinetics

H 2 /H STATE-TO-STATE KINETICS Updated model  Σ + 1 : , ’, ”  B B B Singlets vibrational kinetics = g 1 *  Π Y 1 : , , ’  C D D  g Triplets kinetics + + 3 Σ 3 Σ 3 Π , , b a c u g u + H cation kinetics Negative Ions kinetics 3 The European Physical Journal D (2017), Vibrational kinetics of electronically excited states in H 2 discharges Colonna, G., Pietanza, L. D., D’Ammando, G., Celiberto, R., Capitelli, M., & Laricchiuta, A.

✓ state-to-state ✓ radiative processes The European Physical Journal D (2017), Vibrational kinetics of electronically excited states in H 2 discharges Colonna, G., Pietanza, L. D., D’Ammando, G., Celiberto, R., Capitelli, M., & Laricchiuta, A.

✓ state-to-state ✓ radiative processes U. Fantz, D. Wünderlich, ADNDT (2006) The European Physical Journal D (2017), Vibrational kinetics of electronically excited states in H 2 discharges Colonna, G., Pietanza, L. D., D’Ammando, G., Celiberto, R., Capitelli, M., & Laricchiuta, A.

✓ state-to-state ✓ radiative processes + + Σ + → Σ Π 1 1 1 ✓ energy profile cross section H ( , ) H ( , , ') X v e B C v 2 2 g u u 1 B u + C 1 Π u υ = 0 0 → 5 0 → 0 Cross section Å 2 0 → 10 0 → 5 5 → 10 5 → 20 0 → 0 10 → 7 Collision energy (eV) Collision energy (eV) semiclassical IPM - R. Celiberto et al., ADNDT (2001) The European Physical Journal D (2017), Vibrational kinetics of electronically excited states in H 2 discharges Colonna, G., Pietanza, L. D., D’Ammando, G., Celiberto, R., Capitelli, M., & Laricchiuta, A.

BE f scaling ✓ state-to-state Tanaka et al. Reviews of Modern Physics (2016) Kim, J Chem Phys (2007) ✓ radiative processes CCC approach M.C. Zammit et al., Physical Review Letters (2016) ✓ energy profile cross sections Ajello et al., Physical Review A (1984) Wrkich et al., Journal of Physics B (2002) ✓ accuracy υ = 0 semiclassical IPM - R. Celiberto et al., ADNDT (2001) The European Physical Journal D (2017), Vibrational kinetics of electronically excited states in H 2 discharges Colonna, G., Pietanza, L. D., D’Ammando, G., Celiberto, R., Capitelli, M., & Laricchiuta, A.

Fast (ns-pulsed) discharges in hydrogen Fast (ns-pulsed) discharges in hydrogen excited state concentration excited state concentration & singlets vibrational distributions & singlets vibrational distributions 250 200 150 E 0 /N (Td) 100 50 0 0 5 10 15 20 time (ns)

Fast (ns-pulsed) discharges in hydrogen Fast (ns-pulsed) discharges in hydrogen excited state concentration excited state concentration & singlets vibrational distributions & singlets vibrational distributions … no quenching … no quenching The European Physical Journal D (2017), Vibrational kinetics of electronically excited states in H 2 discharges Colonna, G., Pietanza, L. D., D’Ammando, G., Celiberto, R., Capitelli, M., & Laricchiuta, A.

Fast (ns-pulsed) discharges in hydrogen Fast (ns-pulsed) discharges in hydrogen hydrogen negative ion concentration hydrogen negative ion concentration no quenching The European Physical Journal D (2017), Vibrational kinetics of electronically excited states in H 2 discharges Colonna, G., Pietanza, L. D., D’Ammando, G., Celiberto, R., Capitelli, M., & Laricchiuta, A.

H + /H RESONANT CHARGE EXCHANGE in DEBYE PLASMAS Dense plasmas − λ / r e D λ D = [ k B T e /(4 π n e )] 1/2 is the Debye lengt = − U r H + H + → H + + H Resonant charge exchange for H-H + in Debye plasmas A. Laricchiuta, G. Colonna, M. Capitelli1, A. Kosarim, and B. M. Smirnov Eur. Phys. J. D (2017)

H + /H RESONANT CHARGE EXCHANGE in DEBYE PLASMAS (1 s ) + H + ASYMPTOTIC APPROACH 10 4 0.9 a 0 2 ] Charge-Exchange cross section [ a 0 1.0 a 0 10 3 1.2 a 0 1.4 a 0 3.0 a 0 λ D = ∞ 10 2 10 –2 10 –1 10 0 10 1 10 2 E cmf [eV] icchiuta, A., Colonna, G., Capitelli, M., Kosarim, A., & Smirnov, B. M.. onant charge exchange for H–H + in Debye plasmas European Physical Journal D (2017).

H + /H RESONANT CHARGE EXCHANGE in DEBYE PLASMAS (1 s ) + H + ASYMPTOTIC APPROACH vs QUANTUM 10 4 0.9 a 0 Charge-Exchange cross section [ a 02 ] 1.0 a 0 10 3 1.2 a 0 1.4 a 0 3.0 a 0 λ D = ∞ 10 2 10 –2 10 –1 10 0 10 1 10 2 E cmf [eV] u, J.G. Wang, P.S. Krstic, R.K. Janev, J. Phys. B 43, (2010) icchiuta, A., Colonna, G., Capitelli, M., Kosarim, A., & Smirnov, B. M. onant charge exchange for H–H + in Debye plasmas European Physical Journal D (2017).

H + /H RESONANT CHARGE EXCHANGE in DEBYE PLASMAS n = 2, 3) + H + EXCITED STATES H* 11 a 0 3 d m=2 4.6 a 0 2p m =1 2 p xy 2 ] 2 ] Charge-Exchange cross section [ a 0 Charge-Exchange cross section [ a 0 10 4 10 4 5.0 a 0 0.9 a 0 15 a 0 7.0 a 0 20 a 0 λ D = ∞ 10 3 10 3 λ D = ∞ λ D = ∞ 1 s 1 s λ D = ∞ 10 2 10 2 10 –2 10 –1 10 0 10 1 10 2 10 –2 10 –1 10 0 10 1 10 2 E cmf [eV] E cmf [eV] icchiuta, A., Colonna, G., Capitelli, M., Kosarim, A., & Smirnov, B. M.. onant charge exchange for H–H + in Debye plasmas European Physical Journal D (2017).

Kinetic and divertor modeling F. Taccogna, P. Minelli, D. Bruno, S. Longo, R. Schneider Chem. Phys. (2012)

Reduction of the Divertor Region to 1 Dimension - e/H + density: n p =10 21 m -3 o Input data: - e/H + Temperature : T p =5 eV (detached divertor plasma condition) - B=1 Tesla; θ =85 ° Z o Simulation domain: l=0.3 mm Every Particle carries: - species: e, H + , H 2 + , H - ; H, H 2 (X 1 Σ g + ) o - axial position, velocities: (z, v x , v y , v z ) - quantities averaged over x,y (uniformity) - quantum energy levels: - electronic: n=1s-3s for H - vibrational: v =0-14 for H 2 o Collision Methodology: - Plasma-Plasma (e+H 2 + /H - +H + /H - +e) - Plasma-Neutral - Neutral-Neutral relaxation (Vt/VT/VV) o Boundary module: - H 2 ( v ) wall relaxation-dissociation - H wall recombinative desorption (ER/LH) -> H 2 ( v ) vibrational excitation (A-V) - H + /H 2 + / wall Auger neutralization -> H 2 ( v ) vibrational excitation (s-V)

Particle-in-Cell / Direct Simulation Monte Carlo Model of Plasma-Gas Coupling in the Divertor Region (PIC-DSMC) e, H + H 2 + Solution of Poisson’s Plasma parameters equation n p , v p , T p , … Φ , E Plasma source and boundary effects r i , v i , H(n), H 2 ( v ) DSMC Calculation of force Particle collisions v i PIC acting on particles F i = E i + v i x B i Particle collisions v i Integration of particle Plasma source and motion equations boundary effects Gas parameters r i , v i r i , v i n g , v g , T g , … H(n=1-3) H 2 (X 1 Σ g + ( v =0-14)) 20

Results: Plasma density (m-3) bulk wall −0.25 −0.2 −0.15 −0.1 −0.05 0 −0.2 −0.15 −0.1 −0.05 0 Distance from divertor plate z(mm) z (mm) z (mm) z(mm) agreement with probe measurement non-Maxwellian behavior −1.6 −1.2 −0.8 −0.4 0 −0.2 −0.15 −0.1 −0.05 0 z (mm) E(eV) z(mm)

Results: Gas − 0.25 −0.2 −0.15 −0.1 −0.05 0 z (mm)

Results: MAR processes production of precursors peaks close to the wall due to high vibrational excitation H 2 ( v ) −0.25 −0.2 −0.15 −0.1 −0.05 0 −0.25 −0.2 −0.15 −0.1 −0.05 0 z (mm) z (mm) H − + H + → H + H a) e + H 2 ( v ) → H + H − , b) H + + H 2 ( v ) → H + H 2 + , H 2 + + e → H + H

Aerospace Sciences

Motivation Planet Speed Heat flux Enthalpy Acceleration (km/s) (kW/cm2) (kJ/cm2) (g) Jupiter 47.4 30 300 250 Saturn 26.9 1.3 257 Uranus 22.3 5.1 32.8 Modelling chemical kinetics and convective heating in giant planet entries P. Reynier, G. D'Ammando, D. Bruno, Progress in Aerospace Sciences (2018)