Multicolor mm/submm TES Bolometer Camera development for ASTE. Tai Oshima (NRO/NAOJ)

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1 Multicolor mm/submm TES Bolometer Camera development for ASTE Tai Oshima (NRO/NAOJ)

2 Science with the Multicolor camera AzTEC mm camera on ASTE( ) lots of successful observation projects What comes next? Multicolor mm/submm camera Photo-z of Submillimeter galaxies Sunyaev-Zel dovich effect of clusters of galaxies SEDs of dust in our galaxy and nearby galaxies Science cases from this WS

3 NAOJ Development team & collaboration T. Oshima(PI), T. Takekoshi, H. Arai, A. Hirota, T. Sato, H.Iwashita, J.Maekawa, T. Minamidani, H. Matsuo, R.Kawabe Hokkaido University S. Nakatsubo, S. Mori University of Tokyo T. Izumi, S. Ishii, Y. Tamura, K.Kohno UCBerkeley (Bolometer wafer, horn array, etc.) B. Westbrook, A. Suzuki, A.T. Lee McGill (readout): M. Dobbs Cardiff (optical filters) : C. Tucker, P.A.R. Ade

4 Multi Color mm/submm TES Bolometer Camera for ASTE Generation 1 2 No. of Bands 2 2 Wavelength 1.1mm/850mm 850mm/450mm Frequency 270/350GHz 350/650GHz bandwidth GHz / GHz / GHz GHz No. of Pixels 169 / / 881 Beam(FWHM) 28 /22 22 /11 Field of View( ) Options 3 or more color with multi-chroic

5 Introduction to TES Bolometer System overview (Preliminary) results of the commissioning run on ASTE

6 What is a Bolometer? Low temperature thermal detector Typically T < 1K Measures input power as temperature rise 1. Power input to absorber 2. Temperature rise measured by thermometer 3. Readout as electrical signal Thermometer types Semiconductor (e.g. AzTEC) Transition edge Sensor (TES) radiation thermometer absorber thermal link G C, T T stage

7 TES Transition Edge Sensor(TES) Utilize rapid resistance change in superconducting-normal state transition Advantage High sensitivity Multiplexable using Saturation low noise SQUID readout large power input drives TES normal lose sensitivity Careful design of saturation power + Electro-thermal feedback Operation under Electro Thermal Feedback Voltage bias 1. Increase in Power (P) 2. Temperature rise (T) 3. Increase in Resistance (R) 4. Decrease in bias Power (Pbias= V 2 /R )

8 Overview PulseTube cooler antenna control computer 300K warm optics receiver control computer 4K cold optics cryostat DATA He3 cooler 0.25K TES bolometer array LAN 4K SQUID SQUID controller DfMUX backend cryogenics control

9 Optics Requirements to the optics Simultaneous 2 color observation 1st generation : 270GHz & 350GHz 2nd generation : 350GHz & 670GHz FoV ~ 7.5 diameter Fits in the telescope receiver cabin (L1877mm x W2232mm x H1812mm) ~ 2m!!

10 Optics Very compact dichroic optics design Two color optics enclosed in 60cm cube upgradable to wide band multi-chroic bolometers 1812mm Cold reimaging optics Takekoshi+2012

11 Multi Frequency band Use of dichroic filters multiple focal plane(one per a band) BAND1 (270GHz) from M3 BAND2 (350GHz) HDPE Lens Dichroic filter Focal Plane Modules 600mm

12 Horn array 350GHz 271pixels Cross section of a test cut piece

13 Bolometer Array 80mm 271pix Coupled to optics with conical feed horn and waveguide Designed in NRO (Oshima+13) and fabricated in UC Berekeley (Westbrook+12) 2.2mm

14 Spiderweb absorber TES bolometer Al/Ti bilayer TES (Tc~450mK) Spiderweb absorber Thermal link BLING (extra heat capacity to adjust time constant)

15 SQUID Multiplexed Readout SQUID FLL(flux locked loop) 100 series array by NIST MUX method Frequency Domain Multiplexing (fmux) SQUID Summation of AC modulated TES signals in frequency domain (~100kHz bandwidth per TES) TES1 Iout mod. AC current TES2 Sum in freq.-domain TES3.. f3 f2 f1 frequency UCB, McGill

16 Frequency comb Inductor(8) Capacitor(8) 8 combs per SQUID Frequency[kHz]

17 Cryogenics 600mm SQUIDs 4K 250mK He3 sorption cooler Chase He-10 model T=250 mk Hold time > 2 days with window open 50K He3 fridge Pulse tube cooler Cryomech PT410-RM (1.0W@4K) advantage Low vibration Low magnetic field Low frequency of maintenance drawback Cooling power depends on orientation limits the El to 30-90deg

18 Installation to ASTE rx cabin

19 Commissioning at ASTE 2012/ /06 End-to-End test, First light 2013/ /01 Bad sky condition 2014/ /04

20 First image of a Galactic source 350GHz Target: NGC6334I (Hot core) Date: 2014/04/04 06:38:37 Exposure = 20min Map size 14 x14 τ 220GHz ~ 0.13±0.02 El = 54.5deg Scan mode: lissajous Preliminary Extended dust structure clearly detected in quicklook image

21 Beam map 270GHz band beam map image of Mars Sidelobe level ~ 10% >> 3%(design) Subref-z defocus? Subref-xy(Lateral) defocus?

22 270GHz band (τ 220GHz =0.046) Noise Atmosphere 1Hz + harmonics Microphonics from pulse tube cooler? Electronic noise via ground loops?

23 Bolometer array 90% yield No. of bolometers > No. of readout channel just pick out good bolometers to read out SQUIDs 52/56 = 93% Inductor ( Frequency comb) 298/416 = 72% update to higher yield fab process Total 270GHz band: 128/192 = 67% 350GHz band: 170/256 = 66%

24 Unstable sky condition latch large decrease in the optical loading TESs fall into superconducting state and lose sensitivity == latch Recovery from latch Self heating of TES by large bias is not available (zero resistance) Warm up the focal plane and retune bolometers 3hrs due to large thermal mass of focal planes not observer friendly Workaround 1. implement a heater close to the TES additional wirings 2. Add offset resistance to the TES easiest 3. Increase the saturation power not hard update the bolometer array (Design already finished)

25 Summary Overview of the multicolor TES Bolometer camera development for ASTE Successful imaging of Galactic source However, there are some issues to be solved Noise: reduction of 1Hz and harmonics Beam map: improve the optimiziation process of subreflector parameter to reduce defocusing Low yield: update inductor Latch: update bolometer array

26 Future options Multichroic TES bolometer (O Brient+2009) Antenna coupled Utilize existing 2 focal planes Lower frequency GHz 150, 220, 270GHz Higher frequency GHz 350, 450, 650GHz O Brient+2009 Matsushita+1999

27 YOU are invited to join us!! Hardware development Software development Data analysis Science cases