Lecture 11B Appendix: Test Equipment and Vendor Guide

Part III: Systems Integration | SCE Futures

Contents¶

Equipment categories and examples
Selection notes
Summary

!!! warning "Procurement note" Vendor models, prices, lead times, and availability are examples recorded for course use. Recheck current datasheets, quotations, safety certifications, and cryogenic performance before purchase.

!!! abstract "Learning Objectives" - Translate a measurement plan into instrument, cryostat, wiring, filtering, and shielding requirements. - Separate functional requirements from illustrative vendor examples and prices. - Build a thermal and signal-integrity budget before selecting equipment. - Define acceptance tests for purchased or assembled test infrastructure.

Equipment categories and examples¶

Specific recommendations for building a cryogenic SCE test system.

Cryocoolers¶

Vendor	Model	Type	4K Power	Notes
Sumitomo	RDK-408D2	GM	1.5 W	Workhorse, reliable
Sumitomo	RDK-415D	GM	1.5 W	Newer version
Cryomech	PT410	Pulse Tube	1.0 W	Lower vibration
Cryomech	PT415	Pulse Tube	1.5 W	Higher capacity PT
Sumitomo	RP-082B2	Pulse Tube	0.9 W	Compact PT
Bluefors	SD series	Dilution	mK	For quantum work

Compressors: Matched to cold head (Sumitomo CNA-11, Cryomech CP2870)

Coaxial Cables¶

Vendor	Part Number	Type	Z₀	Notes
Micro-Coax	UT-085-SS	Semi-rigid SS	50Ω	Standard
Micro-Coax	UT-047-SS	Semi-rigid SS	50Ω	Lower heat load
Coax Co	SC-086/50-SS-SS	Semi-rigid SS	50Ω	Premium
Coax Co	SC-086/50-CN-CN	Semi-rigid CuNi	50Ω	Moderate thermal
Coax Co	SC-086/50-NbTi-NbTi	Superconducting	50Ω	Lowest loss below T_c
Lake Shore	Type C	Coax	50Ω	Cryo-rated assemblies
Keycom	Various	Semi-rigid	50Ω	Good NbTi options

DC Wiring¶

Vendor	Type	AWG	Notes
Lake Shore	Quad-Twist	32-36	Phosphor bronze, cryo-rated
Lake Shore	Cryogenic Wire	Various	Pre-spooled for cryo
CMR Direct	Manganin wire	32-40	Bulk spools
Supercon Inc	NbTi wire	36+	Superconducting
California Fine Wire	Custom	Various	Many alloys

Connectors¶

Vendor	Series	Type	Notes
Amphenol	SMA	RF coax	Standard, cheap
Rosenberger	SMA/2.92mm	RF coax	Higher quality
Southwest Microwave	2.92mm/2.4mm	RF coax	Precision, expensive
Samtec	SFMC	Flex/board	Cryo-rated micro coax
Hirose	FH12/FH19	Flex ZIF	Works at cryo (not rated)
Omnetics	Nano-D	High density DC	Mil-spec, cryo OK
Glenair	Micro-D	High density DC	Hermetic options

Filters¶

Vendor	Type	Application	Notes
Mini-Circuits	LFCN/HFCN series	LP/HP coax	Cheap, work at cryo
K&L Microwave	Custom	LP/BP/HP	Higher performance
Marki Microwave	Reflectionless	LP	No reflections
API Technologies	Feedthrough caps	DC filtering	Pi-filters
Spectrum Control	EMI filters	DC feedthrough	Integrated filtering
Tusonix	Ceramic caps	Feedthrough	Simple, cheap

Attenuators¶

Vendor	Model	Notes
XMA/Omni-Spectra	Fixed SMA attenuators	Standard, work at cryo
Weinschel	Fixed/Variable	Higher precision
Mini-Circuits	VAT series	Variable
Bluefors	Cryo attenuators	Designed for dilution fridges

Amplifiers (Room Temperature)¶

Vendor	Model	Bandwidth	Noise	Notes
Mini-Circuits	ZFL-500LN+	DC-500 MHz	2.9 dB NF	Low noise, cheap
Mini-Circuits	ZX60-P103LN+	0.5-10 GHz	1.0 dB NF	Wideband
RF Bay	LNA series	Various	~1 dB NF	Good value
Pasternack	PE15A series	Various	Various	Quick delivery

Amplifiers (Cryogenic)¶

These are all expensive ($5-20k+). For low-noise analog readout, there's no cheap alternative.

Vendor	Model	Temp	Notes
Low Noise Factory	LNF-LNC	4K	State-of-the-art HEMT
Cosmic Microwave Tech	CITLF series	4K	HEMT, good availability
Caltech	Custom HEMT	4K	Research-grade
NRAO	Custom	4K	Radio astronomy heritage

Budget alternative for digital signals: Qorvo GaAs MMIC amplifiers (e.g., TGA series) can work at 4K for digital readout where noise figure is less critical. Not characterized for cryo, but worth trying if budget is tight.

Magnetic-shielding vendors¶

Vendor	Material	Notes
Magnetic Shield Corp	Finemet tape/cans	One option; verify low-temperature permeability and processing requirements
Vacuumschmelze	Cryoperm 10	Cryo-rated mu-metal
Amuneal	A4K	Optimized for 4K
MuShield	Mu-metal	Requires annealing
Goodfellow	Pb foil	Lead for SC shield
Alfa Aesar	Pb sheet	Lead sheet stock

Thermometry¶

Vendor	Type	Range	Notes
Lake Shore	DT-670 Si Diode	1.4-500 K	Standard, cheap
Lake Shore	Cernox CX-1050	0.1-420 K	Low B-field sensitivity
Lake Shore	RX-202A RuO₂	0.05-40 K	Best for <4K
Scientific Instruments	Si diode	1.4-500 K	Alternative vendor
Lakeshore	Model 336/372	Controller	Temperature readout

Vacuum Equipment¶

Vendor	Type	Notes
Edwards	nXDS dry scroll	Roughing pump
Pfeiffer	HiPace turbo	Turbo pump
Agilent	TwisTorr turbo	Magnetic bearing (low field)
MKS/Granville-Phillips	Ion gauge	Pressure measurement
Kurt J. Lesker	Feedthroughs	SMA, DC, optical
MDC Vacuum	Flanges, fittings	ISO/KF/CF components
Swagelok	VCR fittings	Gas handling

Thermal Management¶

Vendor	Product	Notes
Apiezon	N grease	Demountable thermal joints
Apiezon	H grease	Higher temp range
Henkel	Stycast 2850FT	Epoxy, permanent joints
CMR Direct	GE 7031 varnish	Wire anchoring
Lakeshore	Copper braid	Flexible thermal links
TAI	OFHC Cu	Custom machined parts

Test Instrumentation¶

Vendor	Type	Notes
Keysight	BERT (M8020A)	Bit error rate testing
Keysight	AWG (M8190A)	Arbitrary waveform
Tektronix	AWG5200 series	Arbitrary waveform, good value
Keysight	Scope (UXR)	High bandwidth scope
Tektronix	Scope	Alternative
Stanford Research	SR830 Lock-in	Low-level AC measurements
Keithley	2182A	Nanovoltmeter (precision V measurement)
Keithley	6221	Precision current source
Yokogawa	GS200	Precision DC source
National Instruments	DAQ	Data acquisition

Automated SCE Test Systems¶

Purpose-built systems for superconducting circuit characterization:

System	Vendor	Features	Notes
OCTOPUX	RedHiTech	32/64/128 channels, ±200µA-200mA bias, 0.5µV precision	Established commercial system; verify the current configuration
ICE-T	HYPRES	Cryogen-free, modular inserts, dual-insert option	Cryostat only (requires separate test electronics)

OCTOPUX System¶

The OCTOPUX is one commercial platform used for automated superconducting-circuit testing. Treat the following as vendor-reported starting points and verify them against the current datasheet and quotation:

Specifications:

Channels: 32, 64, or 128 universal I/O
DC bias: 4 programmable ranges (±200 µA to ±200 mA), 16-bit resolution
Measurement: Differential, 0.5 µV P-P accuracy in 4 kHz BW
DAQ: Up to 2 MS/s, 10 µV P-P noise at 1 MS/s
Interference rejection: Designed to minimize 50/60 Hz and RF pickup

Key capabilities:

Automated I_c measurement for all junction types
On-chip R and L extraction
Multidimensional parametric margin analysis
Real-time oscilloscope with spectral analysis
MATLAB integration for custom scripts
Self-calibration and diagnostics

Common use cases: RSFQ/ERSFQ testing, production characterization, margin mapping

Note: Limited for high-impedance loads (>1 kΩ), not ideal for nanocryotron testing.

HYPRES ICE-T¶

The ICE-T (Integrated Cryogenic Electronics Test-bed) is a turnkey cryostat for SCE testing. Test electronics (bias sources, DAQ) are separate room-temperature equipment.

Features:

Cryogen-free (closed-cycle cryocooler)
Modular electrical inserts (standard or custom)
Single insert (ISO-160) or dual insert (2× ISO-100) configurations
Inserts can also work as LHe immersion probes

Best for: Labs wanting turnkey solution, rapid chip turnaround

FPGA with DAC and ADC¶

For custom or budget-constrained setups:

Component	Options	Notes
FPGA	Xilinx RFSoC (ZCU111, ZCU216)	Integrated ADC/DAC
DAC	AD9164, DAC38RF	High-speed, multi-channel
ADC	AD9208, LTC2387	High-speed sampling
Bias DAC	AD5791 (20-bit), DAC8565	Precision DC
Current source	Custom or Keithley 6221	Low-noise bias

Building custom test systems requires significant software development but offers maximum flexibility for AQFP-specific requirements (e.g., 4-phase AC excitation control).

Flex PCB Vendors¶

Vendor	Notes
Rigiflex	US-based, good quality
Epec	US-based, fast turn
PCBWay	Overseas, cheap prototypes
Sierra Circuits	US, high-end
Flexible Circuit Technologies	Cryo experience

Other Useful Vendors¶

Vendor	Products
Lake Shore Cryotronics	Full cryo catalog
Janis Research	Cryostats, probes
Bluefors	Dilution refrigerators
ColdEdge Technologies	Cryostat integration
Precision Cryogenics	Dewars, cryostats
Cryofab	Dewars, LHe storage
Quantum Design	PPMS, cryogenics
ICE Oxford	Cryostats
Oxford Instruments	Cryostats, magnets
Thorlabs	Optics, opto-mechanics
Newport	Optics, positioning
McMaster-Carr	Everything else

Recommended Starter Equipment List¶

For a basic AQFP test setup:

Minimum viable system:

Item	Suggested	Qty
Cryocooler	Sumitomo RDK-408D2 + CNA-11	1
Vacuum chamber	Custom or vendor	1
Turbo pump	Pfeiffer HiPace 80	1
Roughing pump	Edwards nXDS6i	1
Coax cables	UT-085-SS, 1m	4-8
DC wiring	Lake Shore Quad-Twist	100m
Thermometers	DT-670 Si diode	2-3
Temp controller	Lake Shore 336	1
Finemet tape	25mm × 50m	1 roll
Lead foil	0.5mm × 300mm	1 sheet
DC supplies	Yokogawa GS200	2-4
Nanovoltmeter	Keithley 2182A	1
Scope	Keysight or Tek, ≥1 GHz	1
Pattern gen	Keysight or custom FPGA	1

Add for production testing:

BERT for BER measurement
Multi-channel bias system
Automated margin sweep software
Additional cryocooler systems

Selection notes¶

Start from the required current range, voltage compliance, bandwidth, noise floor, input impedance, isolation rating, connector standard, and cryogenic heat load. A named product is useful only after its current datasheet satisfies those requirements. Prices in this appendix are dated examples, not procurement quotes.

Summary¶

Test Equipment Options¶

LHe dip probe: Direct access and fast turnaround: ideal for debug
Cryocooler system: Closed-cycle operation and automation: ideal for production

Thermal Design Rules¶

Intercept all wiring at 40K (1st stage has 30-50W available)
Budget carefully at 4K (only 1-2W available)
OFHC copper for thermal links, stainless for isolation
Specify contact finishes from the thermal and electrical requirements; verify material compatibility

Signal Integrity¶

Use appropriate coax (SS for low heat, NbTi for lowest loss)
Match impedances (50Ω external, matched to PTL internal)
Set filtering from the required bandwidth and noise budget (an RC stage can be a useful DC-line starting point)

Grounding¶

Single star ground point (usually cryostat chassis)
Choose shield termination from the frequency range and grounding topology, then document it
Use differential signals where possible

Magnetic-shielding checklist¶

Multi-layer: mu-metal (300K) + cryoperm (40K) + SC (4K)
Cool through T_c in low field (<1 µT)
Degauss mu-metal after handling

Example Starting Points to Verify¶

Base temperature: set by the device and measurement margin; below 4.2 K is a common starting requirement
4K heat budget: keep planned loads comfortably below rated capacity; 50% is an illustrative planning target
Vacuum: derive the target from thermal, contamination, and high-voltage needs; <10⁻⁵ torr is one common starting point
Field at chip during T_c: derive from device sensitivity and shielding performance; <1 µT is an illustrative target
Connector torque (SMA): use the connector manufacturer's value; 8 in-lb is a common SMA example
Contraction allowance: calculate it for the actual material stack; 1-2% is only an illustrative range

Check Your Understanding¶

Draft an equipment list for junction I–V and low-speed functional tests, stating the required range or noise floor for each item.
Which vendor-specific entries need a fresh quote or datasheet check before purchase, and which underlying requirements remain stable?
Create three acceptance tests for a newly assembled cryogenic wiring harness before connecting a device under test.

Lecture 11B complete
Select equipment from measured requirements; treat models, prices, and availability as dated examples.

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