Transition Edge Sensor Readout Research Articles

High-performance 1-10 THz integrating sphere.

The SPICA far-infrared instrument (SAFARI), one of instruments of the space infrared telescope for cosmology and astrophysics, requires a calibration source assembly to calibrate the transition edge sensor readout circuits. A high-performance integrating sphere working at SAFARI wavelength (34-230 µm) is essential. A novel process for preparing terahertz integrating spheres was developed. The aluminum surfaces after sandblasting, wet-etching, and gold plating processes demonstrate rough morphology but high reflectance of 0.91 in 1-10 THz. The spatial distribution of the measured output power excellently agrees with the numerical simulation results based on the assumption of uniform surface radiation at the output port.

First characterization of a superconducting filter-bank spectrometer for hyper-spectral microwave atmospheric sounding with transition edge sensor readout

We describe the design, fabrication, integration, and characterization of a prototype superconducting filter bank with transition edge sensor readout designed to explore millimeter-wave detection at frequencies in the range of 40–65GHz. Results indicate highly uniform filter channel placement in frequency and high overall detection efficiency. The route to a full atmospheric sounding instrument in this frequency range is discussed.

Lithographed Superconducting Resonator Development for Next-Generation Frequency Multiplexing Readout of Transition-Edge Sensors

Ground-based cosmic microwave background (CMB) experiments are undergoing a period of exponential growth. Current experiments are observing with 1000–10,000 detectors, and the next-generation experiment (CMB stage 4) is proposing to deploy approximately 500,000 detectors. This order of magnitude increase in detector count will require a new approach for readout electronics. We have developed superconducting resonators for next-generation frequency-domain multiplexing (fMUX) readout architecture. Our goal is to reduce the physical size of resonators, such that resonators and detectors can eventually be integrated on a single wafer. To reduce the size of these resonators, we have designed spiral inductors and interdigitated capacitors that resonate around 10–100 MHz, an order of magnitude higher frequency compared to current fMUX readout systems. The higher frequency leads to a wider bandwidth and would enable higher multiplexing factor than the current $$\sim $$ 50 detectors per readout channel. We will report on the simulation, fabrication method, characterization technique, and measurement of quality factor of these resonators.

Development of Frequency-Division Multiplexing Readout System for Large-Format TES X-ray Microcalorimeter Arrays

We are developing the frequency-division multiplexing (FDM) readout system aimed to realize the 400-pixel transition edge sensor (TES) microcalorimeter array for the DIOS mission as well as large-format arrays with more than a thousand of TES for future space missions such as the ATHENA mission. The developed system consists of the low-power superconducting quantum interference device (SQUID), the digital FDM electronics, and the analog front-end to bridge the SQUID and the digital electronics. Using the developed readout system, we performed a TES readout experiment and succeeded to multiplex four TES signals with the single-staged cryogenic setup. We have experienced two issues during the experiment: an excess noise and crosstalk. The brief overview of the developed system and the details, results, and issues of the TES multiplexing readout experiment is discussed.

Neganov-Luke amplified cryogenic light detectors for the background discrimination in neutrinoless double beta decay search with TeO2 bolometers

We demonstrate that Neganov-Luke amplified cryogenic light detectors with Transition Edge Sensor read-out can be applied for the background suppression in cryogenic experiments searching for the neutrinoless double beta decay of 130Te with TeO2 based bolometers. Electron and gamma induced events can be discriminated from α events by detecting the Cherenkov light produced by the β particles emitted in the decay. We use the Cherenkov light produced by events in the full energy peak of 208Tl and by events from a 147Sm source to show that at the Q-value of the neutrinoless double beta decay of 130Te (Qβ β = 2.53 MeV), a separation of e−/γ events from α events can be achieved on an event-by-event basis with practically no reduction in signal acceptance.

Fabrication and characterization of the superconducting quantum interference device amplifier with Washer type input coil

Superconducting quantum interference device (SQUID) amplifier is best known for its low input impedance, low noise and low power consumption. Nowadays it is widely used for detecting the weak signals. Compared with other methods, the Nb/Al-AlOx/Nb structure Josephson junction based SQUID has the advantages of high transition temperature, high voltage flux modulation index and good heat recycle ability, wide critical voltage range, so it is a very good option for making SQUID amplifier. In this work, we fabricate the overdamped Josephson junction and washer dc SQUID, and test the I-V characteristics at He3 3 K stage temperature and calculate the current resolution of SQUID. The result of SQUID modulation property is good. The magnification becomes larger after increasing the input line number of loops, and the system noise becomes smaller after the join of the LC filter. This work is very important for designing and manufacturing transition edge sensor readout circuits.

White noise of Nb-based microwave superconducting quantum interference device multiplexers with NbN coplanar resonators for readout of transition edge sensors

White noise of dissipationless microwave radio frequency superconducting quantum interference device (RF-SQUID) multiplexers has been experimentally studied to evaluate their readout performance for transition edge sensor (TES) photon counters ranging from near infrared to gamma ray. The characterization has been carried out at 4 K, first to avoid the low-frequency fluctuations present at around 0.1 K, and second, for a feasibility study of readout operation at 4 K for extended applications. To increase the resonant Q at 4 K and maintain low noise SQUID operation, multiplexer chips consisting of niobium nitride (NbN)-based coplanar-waveguide resonators and niobium (Nb)-based RF-SQUIDs have been developed. This hybrid multiplexer exhibited 1 × 104 ≤ Q ≤ 2 × 104 and the square root of spectral density of current noise referred to the SQUID input √SI = 31 pA/√Hz. The former and the latter are factor-of-five and seven improvements from our previous results on Nb-based resonators, respectively. Two-directional readout on the complex plane of the transmission component of scattering matrix S21 enables us to distinguish the flux noise from noise originating from other sources, such as the cryogenic high electron mobility transistor (HEMT) amplifier. Systematic noise measurements with various microwave readout powers PMR make it possible to distinguish the contribution of noise sources within the system as follows: (1) The achieved √SI is dominated by the Nyquist noise from a resistor at 4 K in parallel to the SQUID input coil which is present to prevent microwave leakage to the TES. (2) The next dominant source is either the HEMT-amplifier noise (for small values of PMR) or the quantization noise due to the resolution of 300-K electronics (for large values of PMR). By a decrease of these noise levels to a degree that is achievable by current technology, we predict that the microwave RF-SQUID multiplexer can exhibit √SI ≤ 5 pA/√Hz, i.e., close to √SI of state-of-the-art DC-SQUID-based multiplexers.

Operation of an X-ray Transition-Edge Sensor Cooled by Tunnel Junction Refrigerators

We demonstrate successful cooling of an X-ray transition-edge sensor (TES) using solid-state refrigerators based on normal-metal/insulator/superconductor (NIS) tunnel junctions. Above the TES transition temperature (T c ), we use Johnson-noise thermometry to measure the cooling performance. In this regime, the NIS refrigerators cool the TES from 300 mK to 220 mK and from 220 mK to T c =160 mK. Below T c , we also observe cooling and demonstrate that the operation of the NIS refrigerators introduces no detectable noise into the TES readout.

TES microcalorimeter readout via transformer

Readout configuration for Transition Edge Sensor (TES) electrically coupled to a low noise warm front-end via transformer is studied. The study was aimed at the implementation of the readout involved in imaging with microcalorimeter detector arrays using frequency multiplexing technique (Appl. Phys. Lett. 81(1) (2002) 159). A model describing both TES electrothermal reaction and the readout response is investigated. Contribution of electronic noise to TES energy resolution is calculated. Prospective readout architecture with TES electrical biasing from the warm readout side is introduced. The architecture allows building of large imaging detector arrays with TES. It is shown that an unprecedented combination of imaging and spectrometry features can be achieved with TES readout via transformer.