The Crea(on, Analysis, and Veriﬁca(on of a Comprehensive Micro-‐Ion Thruster Model Seminar Presenta(on Max Bodnar March 2015 1 Thesis Goals •  The crea(on of a comprehensive mathema(cal model of an ion thruster – Included submodels: Physical, Magne(cs, Electrosta(cs, Plasma physics, Power deposi(on •  Analyze the performance and characteris(cs of the models – Run op(miza(on on the models to iden(fy solu(ons to the models with increased performance •  Verify the results of the models – Use previous theses, NSTAR and NEXT data, and new test data to verify the models and results MiXI Background •  MiXI – Miniature Xenon Ion Thruster –  Originally developed by Dr. Wirz (UCLA) in 2001 –  CalPoly-‐V1 created in 2009 for thermal tes(ng –  CP-‐V2 created in 2011 for opera(onal tes(ng –  CP-‐V3 created in 2012 implemented a hollow cathode tube (current model) •  Tested for performance by Knapp and for thermal proper(es during opera(on by Parker MiXI Thruster – Physical Model •  Thruster Assembly –  3 cm diameter x 3.3 cm tall discharge chamber –  Contains anode pieces, grids, magnet arrays, mounts, and ceramic isolators •  Hollow Cathode Assembly –  Barium impregnated tungsten insert –  Consists of a heater core, graphite keeper, chassis, fuel inlet, and ceramic isolators Discharge Chamber – Magne(cs Model •  Designed in FEMM (Finite Element Method Magne(cs) –  Uses the physical model of from Solidworks to build the edges and points –  Material proper(es and magne(c characteris(cs assigned in FEMM •  3 Ring-‐Cusp conﬁgura(on –  AHempts to provide two dis(nct areas within the chamber •  High strength near cusps •  Low strength uniform along the center •  Samarium-‐Cobalt grade 27 magnets –  3mm (r) x 1mm (h) disk magnets –  11,000 G surface strength –  325O C maximum temperature Discharge Chamber – Magne(cs Model Discharge Chamber – Magne(cs Model Magne(cs Model Conﬁgura(ons Magne(cs Model Conﬁgura(ons Magne(cs Model Conﬁgura(ons Electrosta(c Model •  Designed in FEMM (Finite Element Method Magne(cs) –  Uses the physical model of from Solidworks to build the edges and points –  Material proper(es and magne(c characteris(cs assigned in FEMM •  Other stuﬀ about the electrosta(cs model, this one is much more simple and didn’t vary with conﬁgura(ons, just show sample conﬁgura(on with the beam poten(al high Plasma Physics Model •  Can control only a few inputs to the real thruster, the code was wriHen to emulate that restric(on •  Thrusters have throHle points governed by the beam current Ib and mass u(liza(on ηm –  This throHle point value is achieved by altering the inputs available to the user: Fuel mass ﬂow, Discharge current Id, and Keeper current Ik –  Performance characteris(cs can be altered and rely on the physical and electromagne(c conﬁgura(on (from FEMM) –  All other values for the plasma model are solved internally • 
• 
• 
• 
Electron temperature TeV Plasma poten(al φ Plasma densi(es ne,i,0 Discharge loss ηd Plasma Physics Model •  The outputs from Electron Temperature and Plasma Discharge submodels are used in the Power calcula(ons –  Calculates Thrust, Isp, Beam power, Total power, Electrical eﬃciency ηe, Dissipated power, Thrust to power ra(o, Total eﬃciency ηT •  Plasma physics model set up as input to fmincon in Matlab –  Able to op(mize around any number of variables –  Used to calculate the op(mum solu(on for a given physical conﬁgura(on Plasma Physics Model Output •  Sample output from code and op(mizer •  Compare in table the performance characteris(cs from the previous thesis and what I get from the op(mizer –  Might need to do some work on the op(mizer to prevent always pushing the boundaries on some supplies •  Total eﬃciency, plasma parameters, set points throHle points Power Deposi(on – Thermal Model •  Talk about the sinks of power, look at that thermal power paper again, •  Fix thermal code and replicate that table type output with my code and display that here •  Talk about how the output of this code is more of a veriﬁca(on and numbers should match what comes from the plasma model in some points and the power model in others •  Talk about how much of what I was trying to do was reduce the en(re thermal load on the system so the thruster can run at steady state since the previous theses had to stop aier a few minutes of tes(ng •  Discuss and use the next slide or so to show thermals from Parker Thermal model output •  My data comparisons •  Tabular output •  Keeping this picture because I might need it for parkers graph Photo courtesy of Sam Parker Thermal Test Results -‐ Parker Photo courtesy of Sam Parker Tes(ng •  Tes(ng results and comparison with plasma parameters from models and power levels to power code •  More to go here… •  Langmuir tes(ng, some langmuir sweeps and results table comparison of parameters •  Will also want to have a table with diﬀerences between conﬁgura(ons that I have data for (currently only 2 L) •  Results of tes(ng when trying to run op(mum code values and comparison to theori(cal Tes(ng s(ll •  Tes(ng stuﬀ Future work •  More tes(ng and data acquisi(on •  Compare conﬁgura(ons through tests and code •  Try to get op(mal run solu(on for this thruster •  Maybe try to get maximum thrust/power eﬀect from the thruster if I can and I get ambi(ous Summary/Comple(on of Goals •  Sort of a thesis summary here •  Did I complete the goals I was trying to •  What did I not, what s(ll needs work?