ConX – XEUS meeting Panu Helistö, Mikko Kiviranta

ConX – XEUS meeting

Panu Helistö, Mikko Kiviranta

Utrecht, 26-27.10.2004

VTT TECHNICAL RESEARCH CENTRE OF FINLAND

VTT Board

VTT Electronics

VTT Information Technology

VTT IndustrialSystems

VTT Processes

VTTBiotechnology

VTT Buildingand Transport

Technical Research Centre of Finland

(VTT)

TTE Board

Microelectronics

Microsensing

Tele-communications

Networks

InformationSystems

Media

Human Interaction

TechnologiesInformation Technology

(TTE)

MEMS Sensors

RF Sensors

Quantronics

Optical Sensors

Biosensors

Microsensing

Thin film technology


Quantronics and thin film technology

Quantronics• Heikki Seppä• Panu Helistö• Juha Hassel• Mikko Kiviranta• Arttu Luukanen

(at NIST until mid2005)• Antti Niskanen• Jari S Penttilä• Hannu Sipola

Topics• Superconducting sensors, electronics

and standards (SQUID, Josephson voltage, bolometers)

• Mesoscopic electronics (BOT, sluice Cooper pair pump)

• Optimised and integrated readout electronics (e.g. for MEMS sensors and bolometers)

• R&D projects related to electricity metrology

• STJ detectors (X-ray for ESTEC, protein flight-time mass spectroscopy)

Thin film technology• Ilkka Suni• Markku Ylilammi• Leif Grönberg• Clean room

technicians

• 1700 m2 class 10/100 clean room


SQUID sensors

• SQUID (superconducting quantum interference device) is the most sensitive magnetic field sensor

• Almost 20 year background in SQUID applications

• Novel SQUID and readout concepts: unSQUID, hgSQUID, noise cancellation,…

• Industrial standard SQUID process

• World leader in biomagnetic SQUIDs

• SQUID - ‘ideal’ for reading out cryogenic calorimeter and bolometer signals – (low4 power, impedance, noise, temperature)

SQUID

Amplified signal is fed into the readout electronics

Superconducting ring,inner diameter ~ 2 m

Josephson tunnel junctions

Magnetic field in the loop changes the phase of the quantum wave function and changes the current through the ring

Bias current

Quantronics


Comparison of multiplexing methods for TES calorimeter readout

• Extensive theoretical evaluation in collaboration with SRON (mostly unpublished work)

• Conclusions: Frequency Division Multiplexing better than Time Division Multiplexing due to better scalability (in bolometer mode both are equal)

• XEUS requirements difficult but feasible from readout point of view


SQUID readout for TES calorimeters

mK SQUID design for XEUS X03 TRP


SQUID readout for TES calorimeters: dcSQUID

Washer SQUID• Flux noise about 0.1 0 / Hz at 0.4 K

Readout noise, measured atupper and lower point with dVo / dPhi = 0

DUT flux noise at dVo / dPhi = 3.0 V/Phi0

3.0

1.7

0.94

0.53

x 10-7 0 / sqrt(Hz)


SQUID readout for TES calorimeters: unSQUID

(a) Schematics of the damping circuit for the un SQUID.

(b) Chip carrier with the SQUID chip and SMD components.

(c) The time trace of the SQUID current taken in the negative-resistance region indicates stable operation without parasitic oscillation.

Potentially lower noise, improved impedance matching


SQUID readout for TES calorimeters: arraySQUID

Arrays SQUID

• Flux noise about 0.35 0 / Hz with direct RT readout


Low noise SQUID readout for multiplexing applications: bolometer readout

1. THz-range 4 K superconducting bolometer

2. Optimized, FDM compatible SQUID readout

3. Photon limited noise at room temperature

• NEP < 5 fW/Hz1/2

• => NETD <~ 10 mK/Hz1/2

• => Tres ~ 0.3 K @1 kHz

• => video rate imaging feasible

Univ.Jkl


Low noise SQUID readout for multiplexing applications: bolometer readout

Room temperature LNA

• 5 MHz center frequency

• Noise temperature 26 K @ 50 Ohm

SQUID amplifier

• input current noise 2 pA/Hz1/2

• => bolometer noise limited, 2 fW/Hz1/2

0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,870

80

90

100

110

120

130

140

I(A

)

V(mV)

Bolometer current


Low noise SQUID readout for multiplexing applications

Room temperature AC LNA Flow cryostat with optical windows


XEUS/FDM readout challenges

• Amplifier reading out the TES• Noise temperature <= 100 mK @ 10 MHz (SQUID)• Post-SQUID next stage easily dominates noise

• AC biasing/multiplexing• Low impedance levels: very high Q-value filters required• Dynamic range/linearity

• Idle current cancellation• Neg-FB with high loop gain when cable delay is present FB at

baseband, non-standard loop filters.• Effect of higher harmonics• Crosstalk

• Others• Count rate/pileup management• …


Work division in ConX/XEUS technology development

Different possibilities

• Instrument1: ESA

• Instrument2: USA

• TDM based path

• FDM based path

• calorimeter1 SQUID1+LNA1 FDM

• calorimeter2 (SQUID2)+LNA2 TDM

• etc


Finland contribution to XEUS/ConX technology

• mK SQUID + LNA amplifiers, optimized to calorimeters

• FDM(/TDM) electronics development

ConX – XEUS meeting Panu Helistö, Mikko Kiviranta

Documents

Transcript of ConX – XEUS meeting Panu Helistö, Mikko Kiviranta