Microwave SQUID (Stanford) (NIST), Adam Anderson (Fermilab ...
Transcript of Microwave SQUID (Stanford) (NIST), Adam Anderson (Fermilab ...
Microwave SQUID multiplexing (umux) detector modules
Heather McCarrick (Princeton), Hannes Hubmayr (NIST), Adam Anderson (Fermilab), Ari Cukierman
(Stanford)
Design Overview recent example: BICEP/Keck umux with ~500 detectors
umux modules under development for 1800 detectors
Fermilab
● umux detector modules that are 1. compatible with arrays of 1800 detectors and 2. able to be tiled are currently under development.
● The module designs share fundamental parts (e.g. mux chips) but the components needing development differ.
● Module/packaging design is a focus of multiple groups involved with umux.
umux components
Cukierman et al. 2019
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SLACPrinceton & NIST
Key Components
1. Readout module
• umux channels: multiplexer chips• TES bias circuitry: ‘interface’ wafer(s)
or chips• Connection from module to cryostat
wiring• Connection from readout to TESs
2. Detector stack
• Detector array
• Optical coupling components
3. Primary optical coupling
• Horns or lenslets
umux components can be separated into an independent readout module for characterization before integration with the detector array into a detector module.
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psed
view
Example umux detector modules
detector array
backshortreadout
Interfaces within Module
umux modules
under development
umux to TES
umux to cryostat wiring
optical coupling
superconducting flex
Rogers and PCB board
Rogers and PCB board
wirebonds wirebonds superconducting flex/PCB
horns or lenslets
horns or lenslets
horns or lenslets
● The majority of interfaces within the modules are made with wirebonds. One design requires superconducting flex.
● Interfaces to the cryostat wiring are made with Rogers (RF) & PCB (DC) boards or superconducting flex (RF & DC).
● Compatible with horns and lenslets.
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horns or lenslets (current work on lenslets)
wirebonds + PCB
Rogers and PCB board
Interfaces from Module
100 mK - 300 K wiring chainFor an 1800 detector module, umux requires ● 1 or 2 pairs of coaxial cables for the RF signal● 1 DC cable (~37 pin) for the flux ramp signal, TES
biases, & cold amplifiers.
Connectors to/from module● RF: standard RF connector (SMA, SMP, etc.) ● DC: standard DC connector (MDM or zif)
300 K to 4 K wiring for the Simons Observatory SATs and LAT as shown in Sathyanarayana Rao et al. 2019
Example umux RF wiring diagram from Cukierman et al. 2019.
Connection to 100 mK stage● Standard mechanical mounting (e.g. an
interlocking flange)● Modules are designed such that the readout
components extend only in the z-axis, away from the sky
● The above two points allow for close packed modules
Challenges for scaling to S4
• Detector module designs all require some development, whether it be the RF packaging or the DC wiring
interconnects.
• Integrated module performance with 1800 detectors has not yet been demonstrated.
• Demonstration with 1800 channels in a detector module is the current focus of multiple umux groups.
• This includes recent R&D of umux detector modules has led to new designs, currently under testing, that
are expected to improve the RF grounding and environment as well as the interconnect robustness.
• Early module designs decreased the internal quality factor of the resonators; current module designs are
expected to show improvements.
Design 1: universal umux module-copper (UMM-Cu)
UMM-copper1. Mux chips: 28 multiplexer chips that cover an octave of
bandwidth with 1800+ readout channels.2. Routing wafer connects the multiplexer chips in series and
contains TES bolometer bias circuitry. Copper tray: ground and hosts multiplexer chips
3. Rogers board with surface mount SMPs: allow for z-axis entry 4. PCB board: allows for z-axis entry 5. Wirebonds to detector array: around perimeter (not pictured)6. One mechanical module
Microwave multiplexing modules require1. Multiplexer chips
2. Interface wafer(s) or chips
3. RF connection4. DC connection5. Connection from readout to detector array6. Number of mechanical packages
Highlights/status● Builds on the experience with the
UMM-Si● Designed for SO detector arrays● Expect improved RF & DC
connectors as well as a better RF environment and grounding
● Can inherent screening and assembly procedures developed for UMM-Si
● First prototype under testingRF connection
DC connection
routing wafer
150 mm
28 mux chips
copper tray
lid
Wirebonds to TESs around perimeter
Design 2: universal umux module-silicon (UMM-Si)
UMM-silicon1. Multiplexer (mux) chips: 28 multiplexer chips that cover an
octave of bandwidth with 1800+ readout channels.2. RF wafer: connects the multiplexer chips in series.
DC wafer: contains TES bolometer bias circuitry. 3. Superconducting flexible cable: allow for z-axis entry 4. Superconducting flexible cable: allow for z-axis entry 5. Wirebonds to detector array: around perimeter (not pictured)6. One mechanical module
Microwave multiplexing modules require1. Multiplexer chips
2. Interface wafer(s) or chips
3. RF connection4. DC connection5. Connection from readout to detector array6. Number of mechanical packages
Highlights/status● Design has been built and has
evolved for better resonator performance.
● Designed for SO detector arrays● Cryogenically robust● Readout components are easily
integrable with a detector array using wirebonds
● Screening and assembly procedures developed for all components
wirebonds to TESs around perimeter
base for readout testing
Design 3: umux stacking modules
umux stacking modules1. Mux chips: 28 multiplexer chips that cover an octave of
bandwidth with 1800+ readout channels.2. Interface chips: TES bias circuitry
Coax: connects mux chips in series3. Rogers board with panel mount micro SMAs4. PCB board5. Superconducting flex/PCB and wirebonds6. 14 modules connected in series
Microwave multiplexing modules require1. Multiplexer chips
2. Interface wafer(s) or chips
3. RF connection4. DC connection5. Connection from readout to detector array6. Number of mechanical packages
Highlights/status● Builds on the BKuMUX module
design● Designed for SO and BA detector
arrays● Uses vetted parts, mostly from the
BKuMUX demo● Individual packages can be tested ● Design under development
DC connection
RF connection
flex/PCB between readout and TESs
2 mux chip
interface chips
14 modules assembled in a double helix
Design 4: Fermilab detector testing module
UMM-copper1. Multiplexer (mux) chips: Test design has 10 mux chips, will be
extended after initial test.2. DC: superconducting PCB, investigating lithography by SeeQC
RF: coax3. Rogers board with panel mount micro SMAs4. PCB5. Superconducting PCB/wirebonds6. One mechanical module
Microwave multiplexing modules require1. Multiplexer chips
2. Interface wafer(s) or chips
3. RF connection4. DC connection5. Connection from readout to detector array6. Number of mechanical packages
Highlights/status● Design motivated by testing of
lenslet-coupled 100mK low-R detectors from Argonne
● Initial design for partial wafer readout complete
● Parts in fabrication now● Can be extended to read out a full
wafer● Considering SeeQC for
higher-density wiring layers