1 / 14

X-Ray Calorimeter ~ Concept Presentation ~

X-Ray Calorimeter ~ Concept Presentation ~. ADR, HTS Leads, ADR Electronics Peter Shirron/552, Michael DiPirro/552, Tom Bialas/564 Feb 17, 2012. Block Diagram - Cryostat. x-rays. Aperture Cylinder & op htr. Aperture cover. KEY. filters. Detector 50 mK stage. main shell.

lotte
Download Presentation

X-Ray Calorimeter ~ Concept Presentation ~

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. X-Ray Calorimeter ~ Concept Presentation ~ ADR, HTS Leads, ADR Electronics Peter Shirron/552, Michael DiPirro/552, Tom Bialas/564 Feb 17, 2012

  2. Block Diagram - Cryostat x-rays Aperture Cylinder & op htr Aperture cover KEY filters Detector 50 mK stage main shell Calorimeter/ADR insert Vent valve Focal Plane Assembly (FPA) at 50mK 50 mK filters conductive bond Microcalorimeter SQUID readout amplifiers Antico detector thermal link heat switch 3-stage Adiabatic Demagnetization Refrigerator (ADR) superconducting cable ADR Stage 1 50 mK cryostat shells 4K SQUIDs & termination resistors ADR Stage 2 Calorimeter/ADR Insert 0.6 K Detector Control ADR Stage 3 1.8 K Custom cryostat encloses the FPA and ADR, as well as the readout amplifiers ADR Control 4.5 K JT stage 18 K 75 K 260-300 K cold head Loop Heat Pipe to radiator Commercial Cryocooler Cryocooler Compressors

  3. ADR Design Drivers • Heat load at 50 mK • Significantly reduced from earlier concepts using large format detector arrays • Heat sink and heat rejection rate • 4-5 K has been baseline for instrument concepts (4.5 K assumed for this study) • 20 mW of cooling at 5 K is significantly less (~10 mW assumed for ADR) • Magnetic field control • Designs from Astro-H are close to the level of control needed • Temperature stability • Single-shot designs are inherently more stable • Duty cycle • Typical value of 95% requires 24 hour hold time/1 hour recycle time • Margin on heat loads • Even with mature design, require 100% margin on loads • Margin is applied to external loads (detector dissipation, wire conduction, etc.) and internal parasitics, NOT to heat flow between stages during recycles • Magnet current limited to 2 amps

  4. Astro-H Heritage • 3-stage ADR capable of operating with 2 heat sinks (1.3 K and 4.5 K) • Designed to mount to the 1.3 K helium tank • Tank is a large heat capacity between stages • Total mass is 14.9 kg

  5. 3-Stage ADR Design • Astro-H configuration • Configuration for this study

  6. Heat Loads • Heat loads proportionally reduced from IXO design by pixel count (~50%) • 0.56 µW at 50 mK 0.28 µW at 45 mK • 7 µW at 0.6 K 3.5 µW at 0.6 K • 55 µW at 1.8 K 28 µW at 1.8 K • 45 mK is a very conservative control temperature • Captures inefficiency due to limited thermal conductance between salt pill and detector, and thermal gradients in the salt pill

  7. ADR Refrigerant Masses • Optimal stage masses are very close to Astro-H design Stage Refrigerant, mass Astro-H refrigerant, mass 1 230 g, CPA (@ 2 T) 270 g, CPA (@ 2 T) 2 130 g, GLF (@ 3 T) 150 g, GLF (@ 3 T) 3 160 g, GLF (@ 3 T) 150 g, GLF (@ 3 T) • Differences in optimal mass can be rebalanced by adjusting hold temperatures Stage Assumed hold T Balanced hold T Modeled value 1 45 mK 45 mK 45 mK 2 0.6 K 0.6 K 0.6 K 3 1.8 K 2.2 K 2.0 K • ADR modeling assumes Kevlar suspension for 1st stage has a heat intercept coming from 2nd stage

  8. ADR Hold Time • 100% margin applied to heat loads • Stage 3 runs out of current at >24 hours • Stage 1 holds for ~36 hours • Stage 1 mass could be reduced without loss of performance

  9. ADR Recycle • Max heat reject rate is 10.6 mW • Stage 3 heat rejection dominates recycle time • Recycle time is 1.6 hours • 94% duty cycle

  10. ADR Controller • ADRC for Astro-H can be used as-is, with simplification of control algorithms • Temperature readout • Magnet power supplies • Control software (FPGA) • Power • Hold time: 29.1 W • Peak: 55 W • All magnets @ 2 A • (Can avoid this condition) • Mass • 13.7 kg

  11. ADRC Capabilities

  12. Summary • ADR technology is mature • Sizing of Astro-H ADR allows design to be used with modest re-configuration • Hold time is limited by upper stages • Can reduce mass some by reducing size of 1st stage, or keep for extra margin • HTS leads for Astro-H are also usable as-is • Long-lead items • GLF refrigerant (from Konoshima Chemical Co. in Japan) • Low risk approach • Cost (Astro-H actuals as of March 2011 plus estimate to finish) • ADR: $3.5M (Includes BBM, ETU, Flight Unit) • ADRC: $8.7M (Includes BBM, EDU, Flight Unit) • Risks • Magnetic shielding: need to refine models and increase shield mass to achieve lower fringing fields than for Astro-H • Design of Kevlar suspension heat intercept for 1st stage

  13. 3-Stage vs 5-Stage ADR • 5-Stage continuous ADR prototype (TRL 4) • Higher duty cycle (100%) • ~1 mW cooling at 1 K • 5-6 µW at 50 mK • Total mass of <10 kg • Low magnetic fields • For current study • From 1 K intermediate stage, heat load at 50 mK is 0.76 µW • CADR mass can be reduced by 2x • Peak heat reject of ~1 mW • Needs further development to reach TRL 6 2 stages cool continuously to ~1 K (~15 minute cycle) Cryocooler heatsink at 4-5 K 3 stages cool continuously to 50 mK (~15 min cycle) 1 K shield (removed for assembly)

  14. Control Electronics for CADR • Based on Astro-H ADRC • Includes temp. monitor and control • Power based on magnet currents and duty cycle Prototype magnet driver

More Related