Cosmic dust Reflectron for Isotopic Analysis (CRIA)

1
Cosmic dust Reflectron for Isotopic Analysis
(CRIA)
Progress Review April 30, 2007
Laura Brower Project ManagerDrew Turner
Systems EngineerLoren ChangDongwon LeeMarcin
PilinskiMostafa SalehiWeichao Tu
2
Agenda

• Organization
• Background
• Operational Concept
• System Design Requirements
• Subsystem Design
• Project Management Plan

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Organizational Structure
Customer Z. Sternovsky
Administration
System Engineer
Project Manager L. Brower
Student Lead D. Turner
CU Advisors X. Li S.
Palo
Professional M. Lankton (LASP)
Professional P. Graf
Electronics
Thermal
Structures
Manufacturing
Student Lead M. Pilinski
Student Lead M. Salehi
Student Lead W. Tu
Professional M. Rhode (CU)
Professional S. Steg (LASP)
Professional B. Lamprecht (LASP)
Professional V. Hoxie (LASP)
Materials
Ion Optics
Detector
Student Lead D. Lee
Student Lead L. Chang
Student Lead D. Turner
Professional G. Drake (LASP)
Experienced Graduate K. Amyx (CU)
Professional G. Drake (LASP)
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Agenda

• Background
• Operational Concept
• System Design Requirements
• Subsystem Design
• Project Management Plan

5
Dust in Space!

• Space dust provides important clues on the
  formation and composition of our solar system as
  well as other stars.

Several instruments have been launched on past
missions to analyze the flux and composition of
space dust in-situ.
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Time-Of-Flight (TOF) Mass Spectrometers

• Dust is ionized against a target and accelerated
  through an electric field to a detector.
• Ion mass is inferred from Time-Of-Flight.

CDA
CIDA
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Time-Of-Flight (TOF) Mass Spectrometers

• Large target area
• Low mass resolution

• High mass resolution
• Small target area

CDA
CIDA
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Large Area Mass Analyzer
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Large Area Mass Analyzer

• TOF Mass Spectrometer
• Large target area comparable to CDA.
• High mass resolution comparable to CIDA.
• Lab prototype constructed and tested.

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LAMA What is still needed for dust astronomy?
DTS

• 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.
• No interface for dust trajectory sensor (DTS)

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Cosmic dust Reflectron for Isotopic Analysis
LAMA
(A cria is a baby llama)
CRIA
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Project Motivation

• Scale down LAMA to a size better suited for
  inclusion on missions of opportunity.

Improve the Technological Readiness Level (TRL)
of the LAMA concept from TRL 4 to TRL 5.
CRIA
LAMA
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Agenda

• Background
• Operational Concept
• System Design Requirements
• Subsystem Design
• Project Management Plan

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Cosmic dust Reflectron forIsotopic Analysis3-D
View
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CRIA Mass Analyzer Primary Subsystems
IONIZER
Target
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CRIA Mass Analyzer Primary Subsystems
ANALYZER (Ion Optics)
Annular Grid Electrodes
Ring Electrodes
Grounded Grid
Target
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CRIA Mass Analyzer Primary Subsystems
DETECTOR
Detector
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CRIA Concept Operation
incoming dust particle
Example Dust Composition
Key
Species-1 Species-2 Species-3 Target
Increasing mass
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CRIA Concept Operation
negative ions and electrons accelerated to target
target material also ionizes
dust impacts target and ionizes (trigger? t0)
t0
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CRIA Concept Operation
positive ions accelerated towards grounded grid
(trigger? t1)
Ions of Species-1, Species-2, Species-3, and
Target Material
t1
t0
t1
t0
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CRIA Concept Operation
Positively charged particles focused towards
detector
t1
t0
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CRIA Concept Operation
Species-1 ions arrive at detector
Ions of the same species arrive at the detector
at the same time with some spread
Species-1 arrives at detector
t1
t0
t2
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CRIA Concept Operation
Species-2 ions arrive at detector
Species-2 arrives at detector
t3
t1
t0
t2
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CRIA Concept Operation
Species-3 ions arrive at detector
Species-3 arrives at detector
t3
t4
t1
t0
t2
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CRIA Concept Operation
Target material ions arrive at detector
m/?m mass resolution
Target material has characteristic peak
t3
t4
t5
t1
t0
t2
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Agenda

• Background
• Operational Concept
• System Design Requirements
• Subsystem Design
• Project Management Plan

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System Level Diagram
Supporting Electronics
Thermal Control
Line Key Power High Voltage Heat
Data

• High voltage supply
• Oscilloscopes
• Computer
• Power source

• Heaters
• Thermocouples

Structure

• (Gray area)

Mass Analyzer
Instrument Electronics
Detector
Analyzer
Ionizer

• Charge Sensitive Amplifier
• Voltage dividers

(Target)

• Annular electrodes
• Ring electrodes
• Grounded grids

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Minimum Success Criteria

• Achieve working instrument with mass resolution
  of at least
• 100 m/?m (Req 1.TR2)
• Achieve TRL-5 Working prototype tested in
  relevant
• environments (Req 1.TR4)
• Remember Working with Preflight Model only from
  this point on!
• -Designed originally in context of flight to
  help pave the way to TRL gt 5, and ultimately to
  a possible mission of opportunity
• -Requirements have been categorized based on
  this into Preflight only (PF), Flight only (F),
  or Both (B)
• -We must only verify PF and B requirements

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Requirements Flowdown
Level 1 Top Level Requirements
Analyzer
Level 2 System Requirements - Functional
Requirements - Performance Requirements - Design
Constraints - Interface Requirements
Ionizer
Each includes -Functional Reqs -Performance
Reqs -Design Constraints -Interface Reqs
Detector
Electronics/CDH
Level 3 Subsystem Requirements
Structural/Mechanical
Level 4 Component Requirements
Thermal
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Key Performance Requirements
2.PR3 Mass Resolution
2.PR4 Target Cleaning
1.TR8 1.TR9 Adequate Data Set
3.6.PR3 Electronics Op. Temps
Ion optics configuration
Power budget
Operational lifetime
Thermal design limiting range
Electrode voltages
Thermal design
Instrument Size
Instrument Mass
Target material
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Agenda

• Background
• Operational Concept
• System Design Requirements
• Subsystem Design
• Project Management Plan

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Structures Subsystem
Lead Marcin Pilinski Speakers Marcin Pilinski
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Structure Requirements Overview
Requirement Description
3.4DC1 Scaling of Ion optics by 5/8th of LAMA ion optics
3.4DC6, 3.4DC7, 3.4DC8 Electrically isolate high voltages
3.4DC2 Fundamental frequency 50 Hz
3.4DC3, 3.4DC4 Yield FOS 1.5, Ultimate FOS 2.0 in 42g load
3.4DC5 Structure mass lt 15 kg
3.4DC10, 3.4DC11 Light cannot enter instrument except at aperture
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Structure Major Design Trade
30 cm Cylindrical 40 cm Cylindrical 40 cm Hexagonal

Aperture Requirement Not Met Meets aperture requirement Meets Aperture requirement
Medium Material Cost High Material Cost Low Material Cost
80 in-house manufacturing 40 in-house manufacturing 80 in-house manufacturing
9 kg 13 kg 14 kg
40 cm external envelope 48 cm external envelope 53 cm external envelope
80 manufactured parts 80 manufactured parts 116 manufactured parts
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Cylindrical Structure Overall Characteristics
Unique Parts 26
Total No. of Mnf. Parts 80
Mass 13 kg
Fasteners 200
Not including instrument-spacecraft interface
All blind fasteners will be vented
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Hexagonal Structure Overall Characteristics
Unique Parts 45
Total No. of Mnf. Parts 116
Mass 14 kg
Fasteners 300
Not including instrument-spacecraft interface
All blind fasteners will be vented
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Structure Parts Summary
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Structure Parts Summary
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Structure Assemblies
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Structure Annular Electrode Assembly
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The photo-etched grid

• BeCU C17200
• 7 mils in thickness
• 800 manufacturing cost (includes spare)
• Mitigates grid wrinkling and eases integration

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Structure Annular Electrode Assembly
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Structure Main Housing Assembly
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Structure Main Housing Assembly
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Structure Target Assembly
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Structure Target Assembly
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Structure Detector Assembly
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Structure Main Assembly
Main Housing Assembly
Detector Assembly
Target Assembly
Annular Electrode Assembly
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Cable Layout
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Cable Layout Solder Access
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Cable Layout Annular Electrodes
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Cable Layout Ring Electrodes
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Cable Layout Target Electrodes
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Cable Layout Grounded Grid
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Cable Layout Target
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Cable Layout Heater/CSA
Power (twisted-shielded)
Output (coaxial)
Input (coaxial)
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Mechanical Ground Support Equipment Interfaces

• Remove-before-flight cover
• Thermal Vacuum/Vibration Adapter Plate

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Integration Testing Features

• Removal of Detector Assembly for Storage
• Electrical Access
• Reconnecting the CSA
• Panel removal for internal access

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FEM
Design Check Results
Max Displacement 0.122 mm
Min Factor of safety 3.8
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Manufacturing

• Total Manufacturing Time 450 student-hours
• 5 critical/difficult components totaling in 200
  student-hours

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Structure Upcoming Work

• Complete Finite Elements Structural Analysis
• Fundamental mode
• Ultimate and Yield Stresses
• Fastener pull-out strength
• Review Design and Produce Mechanical Drawings

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Detector Subsystem
Lead Drew Turner Speakers Drew Turner
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Detector Driver Requirements
Requirement Description
2.PR2 The instrument shall be able to detect a cloud of 10,000 elementary charges after initial dust vaporization must have sufficiently high gain
2.PR3 The instrument shall measure the mass composition of dust particles with a simulated mass resolution of at least 100 m/?m
3.3.IR1 The detector shall be mounted in a detector casing interface with structure
3.3.IR2 The detector shall electrically interface with the CDH system computer to store data
3.3.IR3 The detector shall electrically interface with the voltage dividing system
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MCP-MA34/2 Microchannel Plate Detector
from Del Mar Ventures

• Two MCPs in chevron stack enclosed in casing with
  leads for wiring (voltage and signal)
• Need to be used in vacuum
• Same as used for LAMA

Images from sciner.com/MCP/MCPMA.htm
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Detector Testing

• Functional tests in vacuum chamber
• UV testing
• MCPs sensitive to UV light (table below)
• Want to know how deep space UV background affects
  detector
• Test with a UV source in vac chamber

Source Wiza, J. Nuclear Instruments and Methods,
1979
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Analyzer Subsystem
Lead Loren Chang Speakers Loren Chang
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Analyzer Requirements
Requirement Description
3.4.DC1 Scaling of Ion optics by 5/8th of LAMA ion optics
3.2.PR2 - PR4 Electrode voltages shall be within /- 10 V of the specified values from SIMION simulation.
3.5.IR2 A voltage divider box shall provide the necessary voltages to the various subsystems.
3.5.PR2 All electronics shall maintain a voltage accuracy of 0.5 on the electrodes.
68
Electrode Voltages

• Ion Optics Configuration
• Simulations done by Keegan Amyx using SIMION
• 5 annular and 8 ring electrodes
• Exact values for electrodes determined ranging
  from 1 - 6 kV
• Electrode Power
• Power in preflight model provided by lab HV
  supply.
• Required electrode voltages can be provided by
  system of voltage dividers.

6 kV, DC
R1
R2
Electrode
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Voltage Divider - Resistors

• Ohmite SlimMox-104 thick film resistors.
• Rated for 10 kV DC operating voltage, -55 - 110C
  temperature.
• Custom resistor values exceed budget, will use
  standard values.
• Non-exact values will introduce some error in
  voltage.

27.43 mm
8.64 mm
22.86 mm
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• Use of series circuit configuration results in
  reduction in
• Discrete resistors needed.
• Power required.
• Resistor value.
• Cascading errors inherent in series
  configuration can be addressed by adding smaller
  corrector resistors during calibration.

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Voltage Divider - Configuration

• Resistors for annular, ring, and target
  electrodes arranged in 3 parallel lines.
• Resistors for each electrode type arranged in
  series.
• Voltage precision of /- 3 V.
• Power Draw 0.15 Watts.
• Requires 46 discrete resistors.

Annular Electrodes
Target Electrodes
Ring Electrodes
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Ionizer Subsystem
Lead Dongwon Lee Speakers Dongwon Lee
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Ionizer Requirements
Requirement Number Description
3.1.FR1 The target shall be made of a high-z material, where high-z is defined as having atomic mass greater than 100 AMU
3.1.FR7 The target shall be thermally conductive
3.1.FR8 The target shall be electrically conductive
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Ionizer

• Material Ag (silver)
• Silver Plating follow ASTM-B-700
• Type I Purity 99.9 min.
• Grade B or C Bright
• 10 µm copper coating between silver plating and
  Al substrate

Parameter Value
Inner f 0.14 m
Outer f 0.40 m
Thickness 100 µm

• Vendor Ano-plate, NY
• Cost 250 shipping

Vendor website www.anoplate.com
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Substrate

• Applying 5 KV on the Ionizer surface
• Soldering to Substrate

Silver Coated Substrate
5KV
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Thermal Subsystem
Lead Mostafa Salehi Speakers Mostafa Salehi,
Laura Brower
Analyzer
Structures
Thermal
Ionizer
Detector
Electronics/CDH
Multi-Layer Insulation
Target Heater Design
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Thermal Requirements
Requirement Description
3.6.FR1 Power allocation is 20 W
3.6.PR1 Target shall be heated to 100oC
3.6.IR1 Target heater shall be electrically insulated from the target
3.6.IR3 Target heater shall be thermally insulated from the instrument
4.6.IR1, 4.6.IR2 The backside of the target heater shall be covered in a low emissivity material
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Design Reference Mission
NGSTP Apogee 200 Re Orbit plane perpendicular
to Sun-Earth line
Magnetopause
CRIA (in halo orb)
Vsw
10-14 Re
/- 20 Re
Re
L2
-5 ltß lt15
Earth
Moon
Sun
240 Re
Earths Magnetotail

• Hot Case
• External structure of instrument in complete view
  of Sun
• CRIA sees 223 K (-50oC)

• Cold Case
• Spacecraft carrying instrument completely shades
  it from Sun
• CRIA sees temperature of 7K

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Power for Target Heater
Minco Heater
Max Power Input 26.18 W
Resistance 5.5 ohm
Size 2 diameter
Lead AWG 24
MINCO Kapton covered thermofoil heater
Temperature Sensing and Heater Control

• 25 W required to heat target to 100C assuming
  worst case environment of 7K
• Lower power heaters take longer to heat target
• 25 W heater will heat to 100C in 2 hrs at min
  environment testing temp of -50C

Controller Type Manual On/off
Sensor Type Thermocouples
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Target Heater Configuration

• The heater is wrapped in a thin Kapton coating
• An additional layer DuPont Kapton FN (Kapton
  type 150FN019) provides the electrical
  insulation sufficient to shield the heater from
  the target at 5 kV.

• Similar heater configuration may be used to
  heat electronics

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Electronics/CDH Subsystem
Lead Weichao Tu Speakers Weichao Tu
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Electronics Requirements (key pre-flight ones)
Requirement Description
3.5.PR1 The voltage ripple on any of the electrodes shall not exceed 0.1 of the applied voltage
3.5.PR2 All electronics shall maintain a voltage accuracy of 0.5 on all the electrodes
3.5.PR3 All electronics used in design shall operate in a vacuum environment without failure
3.5.PR4 The instrument shall be able to detect charge signals on the target, grounded grid, and the detector grounded grid for data triggering
4.5.DC1 The master electronic box shall be located outside of the instrument body (assumed to be with/near s/c electronics)
4.5.DC2 The voltage divider box shall be located inside the instrument body beneath the target substrate
4.5.DC3 The CSA box shall be located inside the instrument body close to the charge detector
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(No Transcript)
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Key Electronic Subsystems -Triggering System

• TR1-Trigger On Target (biased voltage 5 kV)
• TR2 and TR3-Trigger On Grid (Grounded)

85
Triggering System

• TR4-Trigger On Detector
• Include both biased voltage and grounded voltage

86
Triggering Test

• Object To determine which place is the best to
  get the triggering signal from.

• Setup
• CSA box and its connections

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Triggering Test

• Test Procedure
• One CSA, move among different trigger-option
  places
• At each place
• CSA Noise Floor Test
• (for determining trigger S/N)
• Trigger Test
• Laser-simulated impact
• To determine whether resulting signals are
  detectable above the noise floor
• Relocate CSA Box

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Agenda

• Background
• Operational Concept
• System Design Requirements
• Subsystem Design
• Project Management Plan

89
Analysis Tools
90
How to Reach TRL 5
TRL 5 test CRIA in a relevant environment

• Required for TRL 5
• Vacuum Testing
• Test performance of CRIA (measure m/?m) using
  laser ablation of target to simulate dust impacts
• Thermal Vacuum Testing
• Monitor temperature response of structure,
  detector, voltage divider electronics, etc.
  during Thermal Balance Test and Thermal Cycle
  Test
• UV Testing
• Test signal response of detector exposed to UV
• Additional Testing
• Vibration Testing
• Shake/vibe based on NASA criteria for launch

91
Vacuum Testing
Test Matrix
Test Type Component Description Measure/ Record
Functional Target Heater Heat target to 100C Target substrate temp
Performance Instrument Simulate dust w/laser ablation Obtain spectra, monitor voltages
Location CU campus, Z. Sternovskys
lab Operating Pressure 10-5 Torr Cost 0 to
operate vacuum Schedule expect 1 week of testing
in Oct, budget 1 month of testing

• Pre-testing Tasks
• Instrument checkout (test resistors, etc.)

• Lab Support Equipment
• 2 HV Supplies (power detector)
• Oscilloscope

92
Thermal Vacuum Testing
Test Matrix
Test Type Component Description Measure/ Record
Functional Target Heater Heat target to 100C during -50C thermal balance test Target substrate temp
Thermal Balance Instrument Steady state at -50C, 40C Monitor instr temps
Thermal Cycle Instrument Cycle between -50C, 40C Monitor instr temps
Location LASP (MOBI or BEMCO) Operating
Pressure lt10-5 Torr Cost Budgeting 1000 for
oper equip / personnel time Schedule expect 2-3
days of testing in Nov, budget 1 month of testing

• Pre-testing Tasks
• Instrument checkout
• Clean Room practices during assembly
• RGA, TQCM, possibly BOT

• Lab Support Equipment
• Low voltage power supply

93
Schedule
94
Pre-Flight Cost Budget
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Special Thanks

• LASP for providing internal Funding and Support
• CU Aerospace Engineering Sciences Dept. Funding
  and Support
• Keegan Amyx
• Chelsey Bryant
• Josh Colwell
• Ginger Drake
• Paul Graf
• Vaughn Hoxie
• Bret Lamprecht
• Mark Lankton
• Mike McGrath
• Steve Steg
• The Heidelberg dust group
• And of course
• Xinlin Li, Scott Palo, and Zoltan Sternovsky

96
Questions?
97
Backup Slides
98
Design Reference Mission
Launch Phase (1 mo.)
Science Phase (2 years)
Checkout
Time
Launch Phase
Science Phase
99
System Level Diagram
Electronics Master Box
Structure
Thermal Control

• Analog/Digital Converter
• Data storage
• Step-up transformer
• Voltage divider with controller
• Temperature control device
• Interface w/ external electronics and power
  supply

• Aluminum
• Insulating materials
• Connections
• Breakouts
• Interface w/ DTS (flight model)
• Aperture cover (flight model)

• Kapton Heaters
• Aluminum foil tape
• Temp sensor
• Multi-layer insulation

Mass Analyzer
Detector
Analyzer
Ionizer
Electronics Inside Instrument

• Annular electrodes
• Ring electrodes
• Grounded grids

• Microchannel Plate

• Silver coated target at 5kV

• Charge Sensitive Amplifiers
• Detector electronics
• High voltage wiring

100
High Voltage Safety

• Electrodes will be held at high potentials (6
  kV), but very low current. Total power estimated
  to be lt 0.3 Watts.
• Typical resistance of a human body roughly 105
  Ohms. Worst case scenario 103 Ohms (wet or
  broken skin).
• Maximum electrical current exposure roughly 6
  amps.

• Risk mitigation measures
• Ensure that CRIA is powered down when electrode
  contact is possible.
• Ensure that instrument exterior is grounded to
  prevent charge accumulation from self-capcitance.

101
Previous Instrument Comparison
102
Work Breakdown Structure
103
FEM
Part Name Material Mass load
Ring Electrode Aluminum 6061-T6 0.172273 kg 42g
FEM MIN Max
Stress 2516.84 N/m2 1.27445e007 N/m2
Strain 5.00783e-007 0.000612643
Displacement 0 mm 0.12209 mm
104
Part Material Manufacturing Number of Parts Total Mnf. Hours
Hexagonal Base 6061-T6 3-axis CNC mill 1 40
Channel Support 6061-T6 2-axis mill 6 20
Target Substrate 6061-T6 Lathe and 2-axis mill 1 15
Grounded Grid Inner Standoff G-10 2-axis mill 1 5
RBF cover 6061-T6 2-axis mill 1 10
Ring Electrode Standoff Noryl 2-axis mill 48 30
Side access panel 6061-T6 3-axis CNC mill 1 15
Side panel 6061-T6 3-axis CNC mill 5 25
Side panel bracket 6061-T6 2-axis mill (3-axis preferred) 6 20
Inner target electrode 6061-T6 Lathe and CNC mill 4 15
Outer target electrode 6061-T6 Lathe and CNC mill 4 15
Inner target electrode Fixture 6061-T6 2-axis mill 6 10
Outer target electrode fixture 6061-T6 2-axis mill 6 10
Target Substrate Standoff G-10 Band-saw 2 5
Testing Adapter Plate 6061-T6 2-axis mill 1 15
Annular Electrode Standoff G-10 2-axis mill 6 20
Annular Electrode Mount 6061-T6 3-axis CNC mill 1 40
Annular Wiring Fixture G-10 2-axis mill 1 5
CSA box 6061-T6 2-axis mill 1 5
CSA lid 6061-T6 2-axis mill 1 10
Detector Housing 6061-T6 Lathe and 2-axis mill 1 10
Detector grid inner clamp 6061-T6 Lathe and 2-axis mill 1 5
Detector grid outer clamp 6061-T6 Lathe and 2-axis mill 1 5
Detector lid 6061-T6 2-axis mill 1 5
Large Ring Electrode 6061-T6 Lathe and 2-axis mill 4 30
Small Ring Electrode 6061-T6 Lathe and 2-axis mill 4 30
Voltage Divider Box 6061-T6 2-axis mill 1 10
105
Physical Properties of Silver
Properties Silver
Atomic Weight 107.868
Density 10.49 g/cm3 at 20 C
Specific Heat 0.24 kJ/kg
Thermal Conductivity 428 W/m K at 20 C
Electrical Resistivity 14.7 n Ohm m at 0 C
Typical Emittance (e) 0.02
Typical Absorptance (a) 0.07
a/e 3.5

- Other consideration Gold, Radium
106
Insulator material
Properties Noryl G 10
TML () 0.1 0.35
CVCM() 0.0 0.02
Dielectric Strength (KV/mm) 19 1519
Thermal Expansion(10-5in/in/F) 3.3 0.6
Thermal Conductivity (W/m-k) 0.2 0.3
Tensile Strength(psi) 9,600 40,000
Machining Difficulty Moderate Low

• Material G-10
• Electrical Insulation
• Thermal Insulation
• Low Machining Difficulty
• Low Outgassing
• Vendor
• Plastic International

107
Material Properties for Analyzer Subsystem
Material CVCM TML Dielectric Strength KV/mm /Resisitivityohm Typical Electrical Conductivity Mass Density g/cm3 Tensile Strength (psi) Thermal Expansionmu-in/in/F_at_20 C
Al 6063 n/a - 5850 Compare to Cu 19 ksi
Noryl 0 0.1 19.7 - 33
Vespel scp5000 gt1E15 ohm - 1.43 23.4 kpsi 24
Delin 500AF gt1E15 ohm - 1.53

108
Electrode Design

• Design to Goal
• Mass resolution (ie Relative voltage
  accuracy)
• Electrical conductivity
• Low emissivity
• Machinability

• Design Selection
• 5 annular electrodes
• 8 ring electrodes

(10 rings)
(8)
(16)
(14)
(8)
(10)

• Material Selection
• Aluminum T-6061 or 6063, polished
• Emissivity (0.02)

Design Selection
109
Electrode Design
110
Resistor Values (Ring)
Resistance (M?) Resulting Voltage (V) Absolute Voltage Error (V) Discrete Resistors Required
10.5 5874.0 -2.0 2
63.5 5112.0 -1.0 4
68.0 4296.0 -1.0 4
74.5 3402.0 -3.0 4
40.5 2916.0 -2.0 2
44.0 2388.0 -3.0 2
48.5 1806.0 0.0 4
57.5 1116.0 -2.0 4
93.0 3
111
Resistor Values (Annular)
Resistance (M?) Resulting Voltage (V) Absolute Voltage Error (V) Discrete Resistors Required
9.5 5886.0 1.0 3
20.0 5646.0 1.0 1
12.5 5496.0 -1.0 3
6.5 5418.0 -1.0 4
2.5 5388.0 -2.0 2
449.0 4
112
Resistor Parameters

• SLIM-MOX 104
• Temperature Range -55 - 110C
• Power Rating 1.5 W
• Operating Voltage 10 kV DC

113
Electrode Arcing Mitigation
Lower arcing limit at 1.55 Torr
Upper arcing limit at 468 Torr

• Electrodes are separated by 2 mm gaps.
• The strongest electric field (3 x 106 V/m)
  occurs between the innermost ring electrode and
  the grounded grid.
• Arcing will occur if electrodes turned on between
  1.55 - 468 Torr (approx. 3 - 43 km altitude).
• This is well above the operational pressure for
  CRIA.

Breakdown Electric Field
107
Electric Field (V/m)
105
Pressure (Torr)
103
100
Max. Arcing Risk at 4.169 Torr
CRIA operating pressure, 10-5 Torr
114
Arcing

• Electric field required for arcing in a neutral
  dielectric given by Paschens Law. Nonlinear
  function of pressure and gap distance.

115
Expected Impacts
For randomly tumbling object. Per NASA Technical
Memorandum 4527, p.7-3
116
Detectors

• Various MCPs Specs from Del Mar Ventures

117
MCP Detector Configurations

• Chevron Configuration
• Z-stack Configuration

High voltage difference
Output signal
Metal anode
High voltage difference
Output signal
Metal anode
118
MCP Detector Efficiencies
Table from Wiza, J.L. Microchannel Plate
Detectors. Nuc. Inst. and Methods, Vol 162,
1979.
E(10000 parts _at_ 5keV) 8.011e-12 J E(deep space
UV100nm) 1.464e-16J E(deep space X-rays)
1.464e-18J
119
THERMAL ANALYSIS

• The heat flow at each node is given by

Where mi The nodes lumped mass ci The
nodes specific heat T temperature t
time Cji The conductive links Rji The
radiative links Qi The power dissipation at the
node Both steady state and transient runs can
be performed on this model
120
Target Heater Design

• Design to Goal
• Heat target to 100C (based on CDA experience)

• Thermal Analysis
• Cold Case simulation
• Cylinder/ target start at 0 Kelvin
• 100C reached 15 hr
• LASP support from Bret Lamprecht, using AutoCAD
  Thermal Desktop shows 23.5 W power required

Total Power Required 23.5 W

• Options for Reducing Power
• Segment target area and heat in cycles

121
Thermal Control

• MinCo Kapton heater
• Thin semitransparent material with excellent
  dielectric
• Internal adhesive, max temperature 200oC
• Radiation resistant to 106 rads if build with
  polyimide insulated leads
• Honeywell Thermal Switch
• Temperature ranges for Honeywell Thermal Switch
  From -73oC to 371oC
• Operational -54o C to 148.9oC
• Non-Operational -65o C to 177oC
• Mounted to the target substrate

MINCO Kapton covered thermofoil heater
Honeywell Series 7000 Thermal Switch
122
Thermal

• Temperature Sensors

Model Material Dimension Temperature
S651PDY24A (100 O) Miniature spot sensor with wire-wound RTD element Polyimide with foil backing 2 or 3 PTFE leads (7.6 7.6 mm) Lead length 600 mm -200 to 200C

• Temperature Controller

Mounted to surfaces, alongside heaters or on top
of them
Minco controller model Control method Supply power sensor input Sensor input Controlled out put
CT325 On/off 4.7560 VDC PD 100 O platinum RTD Same as supply power
123
Thermal Control Device
- Full power on below setpoint - power off
above setpoint. - Electronic on/off
controllers offer faster reaction time
and tighter control than thermostats. on/off
controllers have a differential (hysteresis or
dead band) between the on and off points to
reduce rapid cycling and prolong switch life. -
With on/off control, temperature never stabilizes
but always oscillates around the setpoint.
124
Thermal Insulation

• MLI Layer Description
• Germanium Black Kapton
• Aluminized Kapton
• Dacron netting
• Double Aluminized Kapton

• Design to Goal
• Reduce thermal swings
• Electrically dissipative

• Design Selection
• Cover external structure with Germanium Black
  Kapton Multi-Layer Insulation

• Hot Case
• With MLI CRIA sees reduced heating power of min,
  1 W, max 11 W (instead of min 26W, max 343 W)
• Assumed MLI e0.03, 13 layer MLI

• Cold Case
• No solar power input
• With MLI CRIA sees temperature of 7K no change

125
Thermal Insulation

• Multi Layer Insulation (MLI)
• Multi layer insulation closely spaced layers
  of aluminized Mylar or Kapton
• Insulation reduces the rate of heat flow per unit
  area between two boundary surfaces and prevents a
  large heat influx

126
Thermal Definitions

• Properties for transmission
• Absorptivity, a ability for the surface to -
  absorb radiation.
• Emissivity, e ability for the surface to emit
  radiation
• View factor, F12 relates fraction of thermal
  power leaving object 1 and reaching object 2

127
Transient Thermal Analysis

• Radiation Heat Flux

where s is the Stefan-Boltzmann constant, and
F12 is the view factor between the surfaces of
both bodies F12The view factor is the fraction
of radiation leaving dA1 intercepted by dA2
where F12 is the view factor, A1 and A2 are the
areas of the different materials surfaces, ?1 and
?2 are the angles between the normal of the
surface and Ls, the shortest distance between
them
128
Instrument Monitoring

• Temperature Sensor
• Decontamination
• Voltmeter Housekeeping (High voltage and low
  voltage)
• Physically separated electronic box
• Ammeter Housekeeping
• Total current in high voltage supply

129
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 effected by
• Sampling rate
• m/?m t/2?t CRIA dt2ns
• The energy and angular spread of emitted ions
• Electronic noise

FWHM full width at half maximum
130
Sampling Rate

• The flight time for ions is approximately

• Required m/?mgt100, however, the instrument can
  achieve m/?m350. For not missing narrow, we
  want m/?m350
• We want to resolve the C peak (m12) with high
  accuracy
• dt2ns would give us 2 measured points for the
  C peak. The number for m100 and m300 would be 6
  and 10.
• Then, sampling rate500MHz

131
CSA Selection A250

• Features Ultra low noise, Low power, Fast rise
  time
• 500/each
• A250 Connection Diagram

132
Application Specific Integrated Circuit
(ASIC)

• Developed in cooperation with the Kirchhoff
  Institute for Physics of the Heidelberg
  University, Germany
• Tests performed
• The front-end (CSA and logarithmic amplifier)
• The transient recorder (32 channels with 10 bit
  ADCs and 1-K sample SRAM).

133
Size Range of Detectable Dusts

• For a two year mission with a 0.1 m2 dust
  detector at 1 AU records only about one particle
  of 10-13 g (0.2um radius) per day and one
  particle of 10-10 g (2um radius) per two weeks,
  respectively.
• Assumption For a decent mass spectrum, at least
  104 ions need to be generated upon the impact on
  the target.

The smallest detectable radius
The largest detectable radius
134

• Verification Plan

• Detector Functional Test Combination of
  detector performance tests usually performed each
  time the detector is powered on with high voltage
  to confirm the detector is operating nominally.
• Short-Form System Functional Test Abbreviated
  version of Long-Form Functional Test, performed
  when the detector is power on without high
  voltage to confirm most electronic and software
  function.
• Long-Form System Functional Test Conducted
  before and after each environmental test to
  verify all functional and electrical interface
  requirements for every phase of the mission.

135
System Level Risk Assessment
136
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?

137
Pre-Flight Cost Budget
138
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