Project by: Dr. Jorge A. Diaz. Physics School, University of Costa Rica, National Center for High Technology (CENAT)

Transcription

1 Test of a Miniature Double-Focusing Mass Spectrometer for the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) at the Advanced Space Propulsion Laboratory Project by: Dr. Jorge A. Diaz Physics School, University of Costa Rica, National Center for High Technology (CENAT) In Conjunction with: Dr. Franklin Chang Diaz Astronaut and Director. Advance Space Propulsion Laboratory (ASPL). NASA-JSC Collaboration: Jared P. Squire, Verlin Jacobson, Greg McCaskill, Andres E. Mora a Vargas. (ASPL-NASA NASA-JSC) Henry Rohrs, Rajiv Chhatwal (Mass Sensors Inc.) A.M.G.D.

2 The Application: What is VASIMR? Next Generation of Rocket Technology to make possible Interplanetary Human Travel Name: VAriable Specific Impulse Magneto-plasma Rocket Uses high temperature plasma confined by electro- magnetic fields that can be modulated to produce variable specific impulse Test of concepts are done at ASPL with the VX-10 chamber Target: MARS by Proof of concept: VX-10. Flight Demonstration VF-10 and prototype at ISS

3 VASIMIR CONCEPT Video: BEKUO STARSHIP using three VASIMR engines

4 Plasma Nozzle Plasma Generation Test Bench on Earth: VX-10

5 VX-10 Experiment at ASPL Probes Superconductive Magnets To Vacuum Chamber Antenna ICRH Plasma Flux Helicon Antenna Gas Inlet

6 Why This Project? Miniature Mass Spectrometer developed at UMN (CDFMS prototype) Distributed Residual Gas Analysis Prototype tested at NASA s Hazardous Gas Detection Lab (Kennedy Space Center) Visit to Houston and conversations with Dr. Franklin Chang Diaz about possible collaboration Provided novel usage of commercial alpha and beta units in harsh environment applications VASIMR VX-10 Test Chamber at NASA s Advanced Space Propulsion Lab VASIMR Test Chamber No residual gas detection capabilities at that point Interest of monitoring ion species ( H2, D2, He, Xe, Ar, ) CDFMS Core

7 Substrate 2 cm Detector The MMS Project at UMN Analyzer Research Goal: To develop a novel miniature mass spectrometer suitable for in situ environmental and harsh environment (e.g. volcanic gaseous emissions) Specific Objective: Substrate Ion Source 2.5 cm Compact Double Focusing Mass Spectrometer (CDFMS) Concept Design and construction of proof of concept miniature mass spectrometer prototype: Compatible with mass production manufacturing techniques Low cost (in large quantities) Portable

8 CDFMS Mass Analyzer: Theory It is based on the mass separation capabilities of sector field analyzers l o mv O Ion Beam Trajectory mv = qv φ = V - V + Mass Selection r o F = qbv qe = F m m = F e B 90 o Cylindrical ExB Sector Field Analyzer c o V l i mv r 2 Single Focusing Direction Focusing (angular spread) MAGNETIC SECTOR Energy Focusing (energy spread) ELECTROSTATIC SECTOR Double Focusing (DF) Ion beam is focused both in direction and energy Higher Resolving Power Usually achieved by analyzers placed in tandem Nier, Mattauch-Herzog MS Crossed ExB DF Analyzer Superimposed elec. & magnetic fields Compact Assembly dr dv = Bv 2E Bv E r v = 0 F F m e = 2 DF Condition

9 CDFMS Ion Simulation SIMION 3D Tuned for Mass 28 Ionization from -1 to 1 mm in z Ion Source Mass 27 amu Mass 28 amu Mass 29 amu

10 Microfabricated Mass Analyzer Electric Fringing Field Correcting Electrodes 0.1 mm Cu V 1 V 2 V 3 V 4 V 5 V 6 V 7 V 8 V 9 2 mm Inner Electrode V + V 1 V 2 V 3 V 4 V 5 V 6 V 7 V 8 V 9 OuterElectro de V Electric Field Correction - vias Fringing field correcting electrodes r = 2mm Ceramic Plates with Correcting Electrodes Copper Cylindrical Electrodes h = 2.5mm Mass Analyzer Cross Section Resistor network

11 Instrument Tested at ASPL Alpha Version of the Integrated Leak Detector (Acronym: α-ild 50) Novel Miniature Mass Spectrometer Instrument based on CDFMS prototype (Patent Application. Licensed by UMN to Mass Sensors) Designed for low cost batch manufacturing Basic element (OEM) for a Field Portable MS Distributed sensing. Internet protocol ILD 50 Specs: Analyzer : 8 mm ExB Double-Focusing Magnetic Sector Mass Spect. Mass Range: amu M/ M: 40 Operating pressure: 10-4 Weight: 153g Size: 40H x 52L x 32W (mm) Remote control through: Internet or wireless Alpha-ILD 50 on KF50 flange

12 KF50 Flange Detector Electrical Connections Ion Source NdFEB 1 T Magnet ExB Analyzer Integrated Leak Detector (α-ild( 50)

13 MMS-VASIMR Project Phase I. August 2001 Main Objectives Provide residual gas analysis and single ion monitoring capabilities to the VASIMR VX-10 test chamber at the ASPL. Test at ASPL new commercial alpha and beta version of the ILD-50 If successful, one possible configuration is to integrate this MMS to the VASIMR main control system to provide feedback information of the rocket in order to manage the amount of mixture that is being injected to the plasma to minimize hot neutrals and enhance performance.

14 Activities MMS-VASIMR Project Phase I. August week visit of Dr. Diaz to ASPL (August, 2001) Installation of alpha unit provided by Mass Sensors Inc at one of the ports of the VASIMR VX-10 test chamber Analyze residual gas concentrations Establish time monitoring of specific ion concentrations both at steady state and while beam is being fired Evaluate high pressure operation of MMS and optimize sensor components to achieve operability at 10 mtorr Optimize hardware and software for user friendly operation

15 Experimental Set-up Single Point Sampling Scheme VX-10 Test Chamber Sampling point KF40 port End wall of VX-10 chamber IDL 50 on KF50 flange KF50 T VX-10 Test Chamber KF40 T KF40 to View port KF50 adapter 90 o tree to avoid high energetic ions from reaching ILD 50 analyzer Gate valve KF40 T Micro Ion Gauge Needle valve Calibration gas KF40 to KF25 adapte

16 Experimental Set-up Electronics and Data acquisition

17 Experimental Set-up Data Collection

18 Propellant Gas Analysis 1.00E E-09 RESIDUAL GAS TEST ILD50 Beta 1 Lab Air with D2 and Ar (6 spect. Avg.) MicroScale DF Mass Spectrometer r = 8 mm Advanced Space Propulsion Lab - JSC/NASA 8/29/01 N2+ Ar+ 8.00E-09 D E E-09 I + (A) 5.00E E E-09 HD+ H2O+ O E-09 Ar E-09 H2+ N E m/z (Da)

19 Residual Gas Analysis VX-10 RGA Turbo, Cryogenic and Diffusion Pumping ASPL -NASA Test 08/30/ E-10 7.E-10 H2O+ N2+ O2+ Hydrocarbon Clusters 6.E-10 CO2+ I+ (A) 5.E-10 4.E-10 P = 9.2e-6 torr 3.E-10 2.E-10 H2+ 1.E-10 0.E+00 C M/Z (Da)

20 VASIMR Plasma Rocket being fired at VX-10 chamber. ASPL-JSC/NASA

21 VX-10 Residual Gas + He pulse. No plasma a-ild 50 Test at ASPL - JSC/NASA 08/30/ E E E-09 He + H2O+ I+ (A) 6.00E E E E M/Z (Da)

22 10 Plasma Monitoring at VX-10. Unit: α-ild 50, Propellant: He Single Ion Monitoring Mode. a-ild 50 Test at VX-10 ASPL-JSC-NASA 9 8 Plasma Generation Plasma Stopped 7 6 Arb units Propellant Injection (He) Time (sec)

23 RESIDUAL GAS TEST ILD50 Beta 1 90% D2 / 10% H2 Bottle MicroScale DF Mass Spectrometer r = 8 mm Advanced Space Propulsion Lab - JSC/NASA 8/29/ E-08 D E E-09 I + (A) 7.00E E E E-09 RP exp ~ 38 RP theory ~ E-09 HD+ 2.00E E-09 H E m/z (Da)

24 CONCLUSIONS and FUTURE WORK The α-ild 50 unit was installed at VASIMR VX-10 test chamber for residual gas analysis and single ion monitoring The theoretical RP (40) was almost achieved over the mass range The designed Mass Range (1-50 Da) ) was verified. Capable of higher mass range with decreased performance Problems: Electronics was not reliable and ion signal to noise problems. p Not good sensitivity. But it is not necessary for this particular r application. New β-ild 50 units are being tested at: KSC in collaboration with the Hazardous Gas Detection Lab. (Dec 2001 and May 2002) University of Costa Rica for volcanic monitoring ASPL on the 2nd phase of the MMS-VASIMR proj. Portable ILD 50 system for 8 months unattended He monitoring at Mammoth Lakes, CA (Aug 2002) New CDFMS based units : 5mm EXB sector for He, H2 leak detection (Mass Sensors Inc.) 30mm ExB sector for high mass range (300 amu) and high sensitivity (ppm( ppm) ) gas analysis (Mass Sensors Inc.) TOTALLY MICROFABRICATED MASS SPECTROMETER (J. Diaz)