Microwave Kinetic Inductance Detectors for optical and nearIR

Microwave Kinetic Inductance Detectors for optical and near-IR astronomy Kieran O’Brien University of Oxford kieran. obrien@astro. ox. ac. uk

UK MKIDs Team The UK Optical/UV MKID Team: Kieran O’Brien, Niranjan Thatte, Angela Taylor, Mike Jones, Ghassan Yassin (University of Oxford) Jo Bartlett, Ian Hepburn (Mullard Space Science Labs) (Stafford Withington (University of Cambridge)) Opto-mechanics/System Read-out Kieran O'Brien, Fermilab MKID workshop, August 2013 Detectors Cryogenics 2

MKIDS@Oxford Building on existing capabilities; Ø Opt/IR instrument building o o o SINFONI@VLT SWIFT@PALOMAR FMOS@SUBARU KMOS@VLT HARMONI@ELT Ø Radio instrumentation o C-BASS Ø Detector development o Sub-mm Combine with other specialist groups Ø MSSL cryogenic group Ø Cambridge detector fabrication group Kieran O'Brien, Fermilab MKID workshop, August 2013 3

Oxford experimental radio cosmology group Design and construction of radio technology for astrophysics Cryostat design (eg 4 K rx using Sumitomo G-M coolers) In-house design of RF components: amplifiers, filters, hybrids, switches etc. Use of CASPER digital backend technology: ROACH I & II, i. ADCs, correlator & spectrometer firmware.

Example: C-BASS South Receiver ~ 4. 5 GHz 0 -500 MHz ~ ~ ~ 500 -1000 MHz i. ADC/ ROACH 1 GS/s Digital correlation polarimeter – two down-converted channels of 500 st nd MHz sampled in 1 and 2 Nyquist zones 2 x ROACH FPGA board each with 4 x 1 GS/s ADC inputs 64 -channel spectrometer per ROACH -- 128 channels in total

Example: RF components 5 GHz cryogenic notch filter Broadband amplifier (manufacture licenced to Atlan. Tec) Broadband 90 -deg hybrid

Millikelvin cryocooler (m. KCC) Designed to provide an interface to the user which can be set to a temperature within the range of 100 m. K to 4 K. Provides continuous cooling Utilises two magnetic cooling chains Ø Fast operating Single module which bolts on to a 4 K interface Designed with ease of use in mind Ø Fully automated with Labview control system Magnetically shielded Ø Each magnet is a 2 T magnet Dimensions: 355 mm height, 120 mm width, 56 mm depth. Total mass: 8. 3 kg Ø 6. 6 kg due to magnets and magnetic shields Kieran O'Brien, Fermilab MKID workshop, August 2013 7

Dynamical mass studies Scorpius X-1 o Bright LMXB o Shows emission lines from irradiated disk o Bowen Blend lines are fluorescence lines on donor star o Use doppler shift of lines to constrain the mass of the compact object o Orbital period = 18. 9 hrs Kieran O'Brien, Fermilab MKID workshop, August 2013 From Steeghs, et al. 2002 8

Dynamical mass studies Scorpius X-1 o Bright LMXB o Shows emission lines from irradiated disk o Bowen Blend lines are fluorescence lines on donor star o Use doppler shift of lines to constrain the mass of the compact object o Orbital period = 18. 9 hrs Kieran O'Brien, Fermilab MKID workshop, August 2013 From Steeghs, et al. 2002 9

Short Period systems MAXI J 1659– 152: o 2. 4 hr orbital period (Kuulkers et al, 2013), shortest period Black-hole Xray binary o r’ = 23. 7 (Kong, 2012) s/n ~1 with Xshooter in 2. 4 hrs Ultra-compact X-ray binaries would have even shorter periods (few minutes) and fainter lines. Possible SNIa progenitors and important GW sources. Kieran O'Brien, Fermilab MKID workshop, August 2013 10

The enemy: Read-out noise Example of effects of read-out noise in short-period systems. KIDSPEC will have much larger wavelength coverage, enabling the combination of multiple lines. Kieran O'Brien, Fermilab MKID workshop, August 2013 Figure courtesy of T. Marsh 11

Instrument requirements Single object Medium spectral resolution (R > 5000) to distinguish velocity components in the emission lines of Interacting Binary systems (and many other applications) Wide passband (0. 35 -2. 4μm) to capture as much of the SED of the object as possible simultaneously Good temporal resolution (< 0. 1 secs) to sample characteristic time -scales (frequencies of variability, light-travel times, orbital periods) in Interacting Binaries Low noise to avoid penalty of time resolution Optimizes collecting power of large telescopes, eg Keck, TMT Kieran O'Brien, Fermilab MKID workshop, August 2013 12

X-Shooter is a 2 nd generation instrument at ESO’s 8. 2 m VLT in Chile Designed as very efficient, single-target, intermediateresolution spectrograph Covers the spectral range from 300 to 2500 nm in a single exposure. Dichroic splits in 3 arms. Intermediate spectral resolution R ~ 4, 000 – 17, 000 depending on wavelength and slit width with fixed echelle spectral format (prism cross-dispersers) in the three arms. Kieran O'Brien, Fermilab MKID workshop, August 2013 13

Example of X-shooter data Spectral resolution 6000, 10400, 6200 Seeing 0. 6” (under-filled slit) Velocity resolution 2 -5 kms-1 depending on wavelength Kieran O'Brien, Fermilab MKID workshop, August 2013 14

IR Arm Optical Arm Kieran O'Brien, Fermilab MKID workshop, August 2013 15

KIDspec or ‘super’-X-Shooter High throughput spectrograph, with echelle grating in low order (<20) to achieve spectral resolution of 510, 000 Cross-disperser is replaced by energy resolution of MKIDs Photon counting detector allows for excellent background subtraction (a problem for eg. Xshooter/VLT) Combined with an image slicer, could give Integral. Field Spectroscopy as well. See also, Cropper et al. , 2003 Kieran O'Brien, Fermilab MKID workshop, August 2013 16

Order-sorting scheme Kieran O'Brien, Fermilab MKID workshop, August 2013 17

Summary UK has significant experience in related technologies Plan to bring together to build KIDSPEC, a single object, high throughput medium resolution optical/IR spectrograph capable of exploiting the unique capabilities of MKIDs Timescale Feb 2014 – build/test read-out system July 2014 – lab demonstration of MKID in m. KCC Summer 2014 – apply for national funding 2017/8 – deployment at telescope Kieran O'Brien, Fermilab MKID workshop, August 2013 18