A5052049533- Superconducting and THz Device Technology
- Physics of Superconductivity and Magnetism
- Particle Detector Development and Performance
- Advanced Electrical Measurement Techniques
- Semiconductor Quantum Structures and Devices
- Radio Frequency Integrated Circuit Design
- Quantum and electron transport phenomena
- Atomic and Subatomic Physics Research
- Calibration and Measurement Techniques
- Superconducting Materials and Applications
- Thermal Radiation and Cooling Technologies
- Advanced Thermodynamics and Statistical Mechanics
- Nuclear Physics and Applications
- Mechanical and Optical Resonators
- Surface and Thin Film Phenomena
- Advanced Semiconductor Detectors and Materials
- Microwave Engineering and Waveguides
- Radio Astronomy Observations and Technology
- Advanced Thermodynamic Systems and Engines
- Astronomical Observations and Instrumentation
- Advancements in Semiconductor Devices and Circuit Design
- Advanced MEMS and NEMS Technologies
- Quantum Information and Cryptography
- Analog and Mixed-Signal Circuit Design
- X-ray Spectroscopy and Fluorescence Analysis
VTT Technical Research Centre of Finland
2015-2024
Tieto (Finland)
2009-2024
SRON Netherlands Institute for Space Research
2002-2021
University of Gothenburg
2019
Sensors (United States)
2001-2012
Alenia Aermacchi
2006
Space (Italy)
2006
Quantum Group (United States)
1999
Tampere University of Applied Sciences
1989-1990
The SAFARI instrument is a far-infrared imaging Fourier transform spectrometer for JAXA's SPICA mission. Taking advantage of the low emission SPICA's 5 K telescope, will provide sky background-limited, Nyquist-sampled spectroscopic 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">'</sup> × field-of-view over 34-210 μm, creating significant new possibilities astronomy. SAFARI's aggressive science goals drive development unique detector system...
Microcalorimeter arrays with superconducting phase-transition thermometers are an attractive alternative for construction of imaging X-ray spectrometers. The low source impedance and operating temperatures make dc SQUIDs good candidates their preamplifiers. In large arrays, the circuit complexity as well heat leakage through wiring some sort a multiplexing scheme desirable. Some topologies time-domain frequency-domain schemes compared. One particular circuit, being developed XEUS space...
We report on the development and demonstration of a MHz frequency domain multiplexing (FDM) technology to read out arrays cryogenic transition edge sensor (TES) X-ray microcalorimeters. In our FDM scheme, TESs are AC-biased at different resonant frequencies in low range through an array high-$Q$ LC resonators. The current signals all summed superconducting quantum interference devices (SQUIDs). have demonstrated for readout 31 pixels using room temperature electronics, filters TES developed...
Reflected power imposes severe linearity problems to the receiver in radio frequency identification (RFID) readers. In this letter, design and realization of a ultra high RFID reader with reflected canceller circuit based on quadrature feedback are presented. Theory measurements signal noise presented as function incident carrier power. The sensitivity is even better than without power: A spectral density at data band -140 dBm/Hz +12 dBm At same time, input compression point +15 achieved....
Flux trapping and random flux movement are common problems in superconducting thin-film devices. Ultrasensitive magnetic field sensors based on quantum interference devices (SQUIDs) coupled to large pickup coils especially vulnerable strong external fields. The issue has become particularly relevant with the introduction of SQUID-based ultra-low-field (ULF) nuclear resonance (NMR) imaging (MRI) techniques. In this paper, we study constraints thin-film-based magnetometers gradiometers as...
SRON is developing an electronic read-out system for array of transition edge sensors (TES) based on the techniques frequency domain multiplexing (FDM) and base-band feedback (BBFB). The astronomical applications our are soft X-ray micro-calorimeters in a potential instrument European mission-under-study Athena far-IR bolometers SAFARI Japanese mission SPICA. In this paper we demonstrate simultaneous locking up to 51 BBFB loops. While locked, in-band noise loops shown reach...
We present a structure and fabrication method for superconducting tunnel junctions down to the dimensions of 200 nm using i-line UV lithography. The key element is side-wall-passivating spacer (SWAPS) which shaped smooth crossline contacting low parasitic capacitance. SWAPS enables formation with at or below lithography-limited linewidth. An additional benefit avoiding excessive use amorphous dielectric materials favorable in sub-Kelvin microwave applications often plagued by nonlinear lossy...
The linear dynamic range available for Frequency‐Domain‐Multiplexed (FDM) read‐out of TES X‐ray detectors is seriously limited by the SQUID current amplifiers used TES‐detectors. Baseband feedback one ways to increase linearity and SQUIDs signals. realized demodulation, low‐pass filtering AM‐signals at amplified summing point, thereby retrieving signals each detector, subsequent remodulation individual detector with phase compensation delay rotation carrier frequency. This algorithm creates...
SRON is developing an electronic read-out system for array of Transition-Edge Sensors (TES) which combines the techniques Frequency Domain Multiplexing (FDM) with Base-Band FeedBack (BBFB). Its potential astronomical applications are in soft X-ray microcalorimeters XMS instrument on International Observatory (IXO) and far-IR bolometers SAFARI Japanese-European mission SPICA. In this paper we focus experimental verification system, demonstrating 16 pixels that simultaneous does not degrade...
This paper summarizes a preliminary design concept for the focal plane assembly of X-ray Integral Field Unit on Athena spacecraft, an imaging microcalorimeter that will enable high spectral resolution and point-source spectroscopy. The instrument's sensor array be ~ 3840-pixel transition edge (TES) array, with frequency domain multiplexed SQUID readout system allowing this large-format to operated within thermal constraints cryogenic system. A second TES detector in close proximity detect...
We are developing the frequency domain multiplexing (FDM) read-out of transition-edge sensor (TES) microcalorimeters for X-ray Integral Field Unit (X-IFU) instrument on board future European X-Ray observatory Athena. The X-IFU consists an array ~3840 TESs with a high quantum efficiency (>90 %) and spectral resolution Δ<i>E</i>=2.5 eV @ 7 keV (<i>E</i>/ Δ<i>E</i> ~2800). FDM is currently baseline readout system instrument. Using quality factor LC filters room temperature...
In the context of ATHENA X-IFU Cryogenic AntiCoincidence Detector (CryoAC) development, we have studied thermalization properties a 2mm x SQUID chip. The chip is glued on front-end PCB and operated cold stage dilution refrigerator (TBASE < 20 mK). We performed thermal conductance measurements by using different materials to glue PCB. These been repeated in subsequent cryostat runs, highlight degradation effects due cycles. Here, present results obtained glues greases widely used cryogenic...
We have constructed a compact dc SQUID electronics unit, in which the noise of room-temperature amplifier is measured by and cancelled out. This makes it unnecessary to use transformer modulation scheme achieve matching between amplifier. The unit contains PI/sup 3/2/-controller has demonstrated bandwidth 100 kHz, 1.2 /spl mu//spl Phi//sub 0///spl radic/(Hz) white level 1/f corner 0.3 Hz flux-locked loop mode. design criteria for noise-cancelled are discussed, including problem excess...
We have measured characteristics and noise of four commercially available SiGe heterojunction bipolar transistors at 4.2 K. One device exhibits 75 pV Hz−1/2 white a 1/f corner 20 kHz 9 mW power dissipation, proving suitable for readout SQUIDs immersed in liquid He. Another 370 5 50 µW still gives useable gain 7 dissipation. This is useful SQUID multiplexers intended closed-cycle refrigerators, which the cooling limited. The achievable dissipation even compatible operation low-temperature...
Local negative feedback derived within the cryogenic stage from output current of a voltage-biased SQUID series array is used to linearize flux response and simultaneously approach noise matching resistance room temperature readout amplifier. The level was 0.5 μΦ0 Hz−1/2 in open loop 0.8 arrangement having 2.2 Φ0 peak-to-peak locking range. degraded 2 an with 7Φ0 Very good linearity observed system regardless modest gain, owing open-loop characteristics which are more linear case than...
We have constructed a two-stage SQUID amplifier intended for multiplexed cryogenic detector arrays. The upper is locally linearized 6 × 80 array showing 0.13 μΦ0 Hz − 1/2 flux noise at 4.2 K. lower 4 3 has decoupled input and feedback coils shows 0.28 Design principles measured performance are reviewed.
The frequency domain multiplexing (FDM) readout of arrays transition edges sensors for the X-IFU/Athena and SAFARI/SPICA instruments requires SQUID amplifiers with low input inductance, flux noise, high-dynamic range power consumption. We report performance two-stage developed at VTT coupled to multiple high-Q LC resonators SRON FDM operating in from 2 5 MHz. SQUIDs have been tested following configurations: 1) two base temperature open input; 2) amplifier 1K front-end low-G TES bolometers;...
Athena is a space-based X-ray observatory intended for exploration of the hot and energetic universe. One science instruments on will be Integrated Field Unit (X-IFU), which cryogenic spectrometer, based large imaging array Transition Edge Sensors (TES) microcalorimeters operating at temperature 100mK. The consists 3800 pixels providing 2.5 eV spectral resolution, covers field view with diameter 5 arc minutes. Multiplexed readout microcalorimeter essential to comply cooling power complexity...