Cardiff University Astronomy Instrumentation GroupIRAM Camera meeting October 13-14, 2008

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Cardiff UniversityAstronomical Instrumentation

Peter AdeWalter GearMatt Griffin

Philip MauskopfEnzo PascaleCarole Tucker

Cardiff University Astronomy Instrumentation GroupIRAM Camera meeting October 13-14, 2008

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Group Programme of Work

• Development of underlying technologies - TES detectors, KIDs, filters and optics

• Development of new instruments and techniques (integration vs. underlying technology)

• Support of instrument AIV and operations

• Main instrument focus - SCUBA2, CLOVER, PLANCK-HFI, HERSCHEL-SPIRE, SPICA-SAFARI, BOLOCAM/AzTEC, BLAST-Pol

+ support of observations and data analysis

I.e. science exploitation

• Over 40 staff and students in the group

Cardiff University Astronomy Instrumentation GroupIRAM Camera meeting October 13-14, 2008

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TES detectors

• Facilities for optical characterisation of sub arrays

- SAFARI (30 - 200 m)

- SCUBA2 (450 - 850 m)

- CLOVER (1400 - 3000 m)

P. Ade, P. Mauskopf, D. Morozov 5 mTES

SiN leg

110 m

Cardiff University Astronomy Instrumentation GroupIRAM Camera meeting October 13-14, 2008

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Readouts and Multiplexing• Micromachined bolometers use CMOS multiplexed

readout can have 1000’s of pixels

• Cryogenic TES bolometers (SCUBA2, CLOVER) use multiplexed SQUID readout can have 1000’s of pixels

BUT SQUID and CMOS multiplexing is complicated

• Is there a simpler way to multiplex sensitive cryogenic bolometers?

RF resonator readout - lots of signals on one coaxial cable

Superconductors have low loss at low (readout) frequencies and high loss (absorption/detection) at THz frequencies

Cardiff University Astronomy Instrumentation GroupIRAM Camera meeting October 13-14, 2008

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KIDs

• New technology for large format arrays

• Detectors and cold electronics simple to fabricate, small number of cables (up to 1000 detectors per coaxial cable)

• Most difficult part the warm readout electronics (wide bandwidth)

Cardiff activities on KIDs:

• LEKID design - Readout, optical coupling

• KID test bed - cryo free

• Starting work on readout electronics

• Ongoing collaboration with Cambridge, SRON, Grenoble, Rome, Trento

P. Mauskopf, A. Porch, S. Doyle, C. Dunscombe

Cardiff University Astronomy Instrumentation GroupIRAM Camera meeting October 13-14, 2008

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Kinetic Inductance Detectors

• Photons break Cooper pairs and change kinetic inductance

• Produces frequency shift in LC resonator (few GHz)

• Multiplexable• High sensitivity• Easy to fabricate

…

RLOSS

KL ML+

Cardiff University Astronomy Instrumentation GroupIRAM Camera meeting October 13-14, 2008

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Lumped element superconducting resonators

Microwave model of a lumped element superconducting resonator

Cardiff University Astronomy Instrumentation GroupIRAM Camera meeting October 13-14, 2008

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LeKIDs fabricated and tested at Cardiff(They work)

Cardiff University Astronomy Instrumentation GroupIRAM Camera meeting October 13-14, 2008

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First light - 1.5 THz on a LEKID

Cardiff University Astronomy Instrumentation GroupIRAM Camera meeting October 13-14, 2008

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Filters

• Cardiff provides filters for most mm-wave astronomical instruments

e.g. SCUBA2, PLANCK-HFI, HERSCHEL-SPIRE, BOLOCAM, SPT, ACT, APEX-SZ, etc.

• These include low pass filters, band defining filters and NIR/optical thermal filters for all temperature stages

• The filter combinations are designed to minimise heat load on the cryogenic system, stray light on the detectors and maximise optical efficiency

Cardiff University Astronomy Instrumentation GroupIRAM Camera meeting October 13-14, 2008

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Other optical components

• Cardiff can also provide antireflection coatings of warm and cold lenses and windows

• Cardiff can also provide waveplate modulators and wire grid (hot pressed) polarisers for polarisation experiments

• Cardiff can provide possible other attachments such as input FTS

• RF modelling, e.g. for optimisation of detector coupling and optics and stray light - HFSS, ZeMAX, GRASP - designed warm coupling optics for BOLOCAM and AzTEC and cold coupling optics for BOOMERANG, BLAST and OLIMPO

P. Ade, P. Hargrave, P. Mauskopf, J. Zhang

Cardiff University Astronomy Instrumentation GroupIRAM Camera meeting October 13-14, 2008

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Instrument support

• Experience in instrument AIV and integration of receivers and telescopes - BOLOCAM, AzTEC, CLOVER, SCUBA2, etc.

• Quick look software programming

• Atmospheric removal algorithms

Cardiff University Astronomy Instrumentation GroupIRAM Camera meeting October 13-14, 2008

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Cardiff University Astronomy Instrumentation GroupIRAM Camera meeting October 13-14, 2008

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BOLOCAM 2 (AzTEC)• Original plan - 2 BOLOCAMs

• Second camera now complete - called AzTEC

• Integrated on JCMT in June, 2005; observing run November - December 2005 +?

• Eventually to be integrated on 50 m LMT

Cardiff University Astronomy Instrumentation GroupIRAM Camera meeting October 13-14, 2008

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BLAST

• Test flight from Ft. Sumner, NM (2003) - 500 m array only

• LDB flights from Kiruna (2005) and McMurdo (2006) - 250, 350 and 500 m arrays

• Data analysis underwaySensitivity/resolution limited by optics in flightLots of data on galactic and extragalactic sources

• Cardiff participation in flight preparation, optics and filters and data analysis. (The instrument focal plane was built at Cardiff)