Kelvinox^®TLM, Top-loading into liquid dilution refrigerator

The KelvinoxTLM is a high performance dilution refrigerator with a base temperature of less than 15 mK and cooling power of more than 400 µW.

Top loading of the sample directly into the 3He/4He mixing chamber via a vacuum lock arrangement ensures good sample thermalisation, high stability of the thermal environment and guarantee of operation in high magnetic field.
Multiple service, multi-user access : unique design which can be used with a range of sample probes such as Swedish rotator or high frequency co-axial lines.
Quick and easy sample change : no need to remove the mixture during sample change, giving quicker experiment turnaround times and reducing the risk of leaks.
Non metallic sample environment : ideal for experiments such as solid state NMR when removing metallic material surrounding the pickup coil resonant circuit is key to accurate measurements. Typically, field sweeps of up to 2T / min leave the temperature of the mixture unaffected.
The KelvinoxTLM is covered by US patent No. 6202439.

Specification
System components/options
Operation
Applications
Images

Base temperature	≤ 15 mK
Base temperature stability	± 1 mK
Maximum temperature	1 K
Continuous operation	Standard
Sample environment	Liquid
Cooling power at 100 mK	≥ 400 µW
Cooling power at 120 mK	≥ 580 µW
3He/4He mixture	◊

Key: ◊ = Included with system

Every KelvinoxTLM is made up from three main components:

Dilution unit - providing ≥ 400 µW at 100 mK measured at the He mixture phase boundary.

Insert - featuring still pumping line, 1 K pot, diagnostic wiring and inner vacuum can.

Top loading probe - ease of access to samples with a range of experimental services.

Automation and control of your dilution refrigerator using the KelvinoxIGH - Intelligent Gas Handling system :

All systems are delivered with a KelvinoxIGH which is a fully automated system which enables complete operation of a dilution refrigerator using sophisticated software and virtual instrument drivers for National Instruments'LabVIEWTM.

Options:

PT100 : 24-way copper/supercon loom wired to the mixing chamber

PT200 : 2 x S1 co-axial cables wired to the mixing chamber

PT210 : 4 x S1 co-axial cables wired to the mixing chamber

PT300 : 2 x UT85-SS-SS coaxial cables wired to the mixing chamber

CAPV/CAP : Capillary line with or without valve

KELMSWR : Swedish rotator - manual

KELMSRWA : Swedish rotator - automation

CS100 : ROTH1, 30 point calibrated RuO2 sensor to 50 mK

CS200 : ROTH2, generic calibration RuO2 sensor

RB100 : AVS47 resistance bridge with rf filtering, cables & IEEE interface

TS530 : Temperature controller for use with AVS47 resistance bridge

IPC : Isobus Picobus converter

HTC: Helium cold trap

Transfer tube

TLMP3 : Spare top loading probe, 34 mm access - tested with system

TLMP4 : Spare top loading probe, 34 mm access - supplied untested at a later date

HE3F : 3He flow meter

VIN : Valves in pumping lines

To load the sample, the probe along with any electrical services and/or sample positioning mechanisms is lowered into the cold 3He/4He mixture via a vacuum lock arrangement. This can be undertaken with the mixture condensed or circulating. The mixing chamber tail is formed from concentric non-metallic tubes, with the outer tube forming the mixing chamber vessel. The inner tube promotes the flow of 3He atoms mixture around the sample region, eliminating temperature gradients. The refrigerator is fitted with a continuous heat exchanger and a stack of sintered silver heat exchangers for optimum base temperature performance. The non-metallic tail construction allows the whole mixing chamber assembly to be inserted into the bore of a high field magnet if desired. Typically, field sweeps of up to 2 T/min leave the temperature of the mixture unaffected.

Research areas	Applications	Experimental techniques
Semiconductors	Quantum Hall Effect Quantum dots Single electron tunneling Quantum computing	Magneto-resistance Hall effect RF transport High frequency conductivity
Solid State Physics	Heavy fermions systems Metal insulator transition Spin glass Mesoscopic systems Giant magnetic resistance	Specific heat DeHaas-van Alphen Oscillations Solid state NMR Electrical resistivity Magneto-resistance Neutron scattering
Superconductivity	Low Tc superconductors Quantum computing Josephson junctions Flux vortices Quantum initial phenomema	Electrical resistivity Scanning spectroscopy(STM/AFM) Squids AC susceptibility
Astrophysics & Cosmology	Low temperature detectors Superconducting tunnel junctions Ge bolometers	Electrothermal measurements Voltage biased measurements Low energy photon detection
Metrology	Quantum Hall Effect Voltage standards Current standards	Magneto-resistance DC & AC low frequency transport and magnetic measurements Single electron tunneling