C osmic dust R eflectron for I sotopic A nalysis (CRIA) Conceptual Design Review Laura Brower: Project Manager Drew Turner: Systems Engineer Loren Chang Dongwon Lee Marcin Pilinski Mostafa Salehi Weichao Tu

2 Presentation Overview Introduction to Problem – Loren Chang Previous Dust Analyzers – Loren Chang LAMA Overview – Marcin Pilinski Introduction to CRIA – Weichao Tu Requirements – Drew Turner Verification – Marcin Pilinski Risk – Laura Brower Current Analyses and Trades – Mostafa Salehi Schedule – Dongwon Lee

Loren Chang 3 Space is Dusty! Space is filled with particles ranging in size from molecular to roughly 1/10th of a millimeter. Dust absorbs EM radiation and reemits in the IR band. Dust can have different properties and concentrations, ranging from diffuse interstellar medium dust to dense clouds, and planetary rings.

4 Comets, asteroids, and collisions in the new planetary system produce interplanetary dust. Interstellar dust is believed to be produced by older stars and supernovae, which expel large amounts of oxygen, silicon, carbon, and other metals from their outer layers. Clouds of dust and gas cool and contract to form the basic building blocks for new stars and planetary systems.

Loren Chang Heritage Past instruments have focused primarily on understanding the flux and chemical composition of cosmic dust. Missions have focused on in-situ measurement and sample return. CDA Aerogel Collector CIDA SDC

6 Student Dust Counter (New Horizons) Polyvinylidene fluoride (PVDF) film sensors. In-situ measurement of dust flux, mass, and relative velocity. Cannot resolve smaller particles (< g) nor measure elemental composition. lasp.colorado.edu/sdc

7 Cosmic Dust Analyzer (Galileo, Ulysses, Cassini) Incoming dust particles ionized, then accelerated through electric field to detector. Time of Flight (TOF) used to infer elemental masses of constituents. Parabolic target is difficult to manufacture precisely. Low mass resolution ( m/Δm) Target R. Srama et al., The Cosmic Dust Analyzer (Special Issue Cassini, Space Sci. Rev., 114, 1-4, 2004, )The Cosmic Dust Analyzer

8 Stardust Interstellar and interplanetary dust particles trapped in aerogel. Direct sample return for analysis of elemental composition on Earth. Requires highly specialized mission. stardust.jpl.nasa.gov

Loren Chang 9 Cometary and Interstellar Dust Analyzer (Stardust) Uses impact ionization principle similar to CDA, electric field in reflectron is parabolic, eliminating the need for a parabolic target. Improved mass resolution over CDA (250 m/Δm) Small target area compared to previous instruments. Roughly 1/20 th target area of CDA. J. Kissel et al., The Cometary and Intersteller Dust Analyzer (Science., 304, 1-4, 2004, )The Cometary and Intersteller Dust Analyzer

Marcin Pilinski 10 Large Area Mass Analyzer LAMA Concept: Sub-systems IONIZER Target

11 LAMA Concept: Sub-systems Ring Electrodes Annular Grid Electrodes Target ANALYZER (Ion Optics) Grounded Grid

12 LAMA Concept: Sub-systems DETECTOR Detector

13 LAMA Concept: Operation incoming dust particle Example Dust Composition Species-1 Species-2 Species-3 Target Key Increasing mass Example Spectrum

14 LAMA Concept: Operation dust passing through annular electrodes Example Spectrum dust passing through grounded grid t0t0 Data collection from detector started

15 LAMA Concept: Operation dust impacts target and ionizes (trigger- t 0 ) negative ions and electrons accelerated to target target material also ionizes Example Spectrum t0t0

16 LAMA Concept: Operation positive ions accelerated towards grounded grid (trigger- t1) Example Spectrum t1t1 t0t0 t1t1 t0t0 Ions of Species-1, Species-2, Species- 3, and Target Material

17 LAMA Concept: Operation Example Spectrum t1t1 t0t0 positive focused towards detector

18 LAMA Concept: Operation Species-1 arrives at detector Example Spectrum t1t1 t0t0 t2t2 positive ions arrive at detector Ions of the same species arrive at the detector at the same time with some spread

19 LAMA Concept: Operation positive ions arrive at detector Species-2 arrives at detector Example Spectrum t1t1 t0t0 t2t2 t3t3

20 LAMA Concept: Operation positive ions arrive at detector Species-3 arrives at detector Example Spectrum t1t1 t0t0 t2t2 t3t3 t4t4

21 LAMA Concept: Operation positive ions arrive at detector Ionized Target Material Example Spectrum t1t1 t0t0 t2t2 t3t3 t4t4 t5t5 Target material has characteristic peak

Marcin Pilinski 22 LAMA is promising, but… Several tasks have yet to be completed: Dust triggering system not yet implemented. No decontamination system. System has not yet been designed for or tested in the space environment.

Weichao Tu 23 C osmic dust R eflectron for I sotopic A nalysis (a cria is a baby llama) Hi, I’m LLAMA Hi, I’m CRIA. Am I Cute?

Weichao Tu 24 CRIA Project Motivation LAMA Development –To scale down the LAMA instrument to a size better suited for inclusion aboard missions of opportunity. Technology Readiness Level (TRL) of LAMA can be further improved from level 4 to level 5 Mission opportunity –A universal in-situ instrument design is needed for future mission that can incorporate high performance and large sensitivity and can be adapted to various missions.

Weichao Tu 25 CRIA Project Goals Mission Goal –Design an instrument capable of performing in-situ measurements of the elementary and isotopic composition of space-borne dust particles Science Goal –Detect dust particles and determine their mass composition and isotopic ratios Engineering Goals –Design an instrument based on the LAMA concept that achieves the following: reductions in size, mass, and power in order to be compatible with possible missions of opportunity –Achieve a Technology Readiness Level (TRL) of five or higher for the instrument – To investigate the limits of scalability of the instrument and determine the upper and lower limits of sensitivity (size: between 50% and 125%) in order to provide statistical data and options for a variety of possible missions

26 Baseline Design Inherited from LAMA concept Triggering system Scaling LAMA by a factor of 5/8 Capable of heating the target area for decontamination Capable of interfacing with a dust trajectory sensor (DTS) A closed design with a cover MCP detector may be changed to a large area detector Heater DTS t -1 t0t0 t1t1 t2t2 Cover

Weichao Tu Baseline Design װ Specifications of CRIA and LAMA ParameterCRIALAMA Effective Target Area (m 2 ) > Mass Resolution (m/  m) >100 (team goal of 200)200 Diameter (cm) 4064 Power Consumption (W) <10>10 Instrument Mass (kg) <10>10

Previous Instrument Comparison Instrument Measurement Type Instrument Type Parameters Measured Mass Resolution Surface Area (m 2 ) CRIAIn-Situ Time-of-Flight Reflectron Flat electrode&Target Flux and Composition >100 (team goal of 200) 0.13 LAMAIn-Situ Time-of-Flight Reflectron Flat electrode&Target Flux and Composition SDCIn-SituPVDFFlux Stardust Sample return Aerogel collectorComposition-0.1 CDAIn-Situ Time-of-Flight Parabolic Target Composition500.1 CIDAIn-Situ Time-of-Flight Reflectron Composition

Requirements: Top Level 1.TR14The instrument shall be derived from the LAMA concept 1.TR21The instrument shall measure the mass composition of dust particles with a simulated mass resolution of at least 100 m/Δm [Team goal: 200 m/Δm]. Mass resolution is derived from the full width of the mass peak, m/Δm = t/2Δt, where t is time of flight and Δt is the base peak-width. 1.TR33The instrument shall be capable of mechanically interfacing with a dust trajectory sensor (DTS) 1.TR42The instrument shall be designed to meet the requirements of TRL 5 1.TR55The total project cost shall not exceed $25, TR66The instrument shall be constructed and verified by 1 December TR77Complete design documentation shall be delivered by 1 May 2007 Drew Turner 28

Drew Turner 30 Requirements Flowdown Analyzer Ionizer Detector Electronics/CDH Structural/Mechanical Thermal Each includes: - Functional Reqs -Performance Reqs -Design Constraints -Interface Reqs Level 1: Top Level Requirements Level 2: System Requirements - Functional Requirements - Performance Requirements - Design Constraints - Interface Requirements Level 3: Subsystem Requirements

Drew Turner 31 Requirements: Levels 2 and 3 Functional Reqs: Define system functions; answer “what”, “when”, “where”, and “how many” type questions about the system. CRIA Example: 2.FR5: The instrument shall be capable of detecting positive and negative ion species. Performance Reqs: Define how well system is to perform its various tasks; answer “how well”, “how often”, and “within how long” type questions. CRIA Example: 2.PR6: The instrument shall be able to record a mass spectrum from Hydrogen to at least m = 300 (amu) and be independent of the triggering method.

Drew Turner 32 Requirements: Levels 2 and 3 Design Constraints: Defines factors that put limits on the system, such as environment and budget. CRIA Example: 2.DC1: The instrument shall have a closed design such that no light can enter the interior except through the field of view. Interface Reqs: Defines system inputs, outputs, and connections to other parts of the system or to some other, external system. CRIA Example: 2.IR1: The instrument shall provide a mechanical interface for the Dust Trajectory Sensor (w/ given mass, dimensions and COG).

Marcin Pilinski 33 Requirement Verification Resources ANALYSISApplicable Req SimIon analysis of time of flight, effective target area. TR2, FR2, PR1, PR6 SolidWorks analysis of mass, structural integrity, thermal properties TR3, FR4, PR4, IR1 TEST Bell-JarFR3, FR6, DC3 Thermal-VacuumPR4 Vibration tableTR4

Laura Brower Solar UV Sources System Level Risk Assessment Detector damaged Noise in spectra Events Mitigation Technol. Risk Risk Level UV reflective electrodes On/Off detector mode UV impact on detector unknown High Mechanical Malfunction Inaccurate spectra / no spectra recorded High No risk mitigation Radiation / Plasma Electronics malfunction Instrument charging Use rad-hard electronics and rad protect electronics Arcing Medium Instrument charging not understood Micro- meteroid Target area damaged Detector damaged Shielding in annular electrode design Medium High probability of impacts Prelaunch Contamination Contaminated spectra Aperture Cover Use clean room Low Common practice Material Outgassing Contaminated spectra Vaporize contaminants with heater Use low outgassing mt’ls Low Materials known Heater temp range can be large Technology limits unknown

Current Analyses and Trades Arcing Preliminary calculation: -Breakdown electric field as a function of pressure for air -Maximum electric field as a function of gap distance for inner electrode -Reduced size increases risk of arcing -Unexplored area: The arcing in the plasma Material outgassing - Material selection to low outgassing specification (G-10, Noryl, ceramic, etc.) - More details on other material properties (thermal expansion, tensile strength, density, etc.)

Current Analyses and Trades Thermal power required -Preliminary calculation on power require to heat target area to 100 o C is on going -Target design is thermally conductive Detector protection against UV and Micrometeoroids -We calculated micrometeoroid flux at 1 AU -UV reflection / absorption by coating instrument interior -Determine impact of UV on detector performance

Dongwon Lee 37 Schedule

Dongwon Lee 38 Schedule

39 Questions?

Backup Slides

Previous Instrument Comparison Instrument Measurement Type Instrument Type Parameters Measured Mass Range (g) Target Area (m 2 ) SDCIn-SituPVDFFlux> Stardust Sample return Aerogel collectorComposition-0.1 CDAIn-Situ Time-of-Flight Parabolic Target Composition CIDAIn-Situ Time-of-Flight Reflectron Composition5 x

Mass Resolution (m/  m) Mass resolution describes the ability of the mass spectrometer to distinguish, detect, and/or record ions with different masses by means of their corresponding TOFs. m/  m will be affected by: –The energy and angular spread of emitted ions –Sampling rate m/  m= t/2  t CRIA: dt=2ns –Electronic noise FWHM: full width at half maximum

Arcing Electric field required for arcing in a neutral dielectric given by Paschen ’ s Law. Nonlinear function of pressure and gap distance.

Expected Impacts For randomly tumbling object. Per NASA Technical Memorandum 4527, p.7-3

Possible Questions What is the elemental composition of cosmic dust? What is the dust flux and its mass dependence? What direction is the dust coming from? What are the differences in composition and size between interstellar and interplanetary dust?

Dongwon Lee 46 Schedule