HelioxTMVL, Sample in vacuum, no 1 K pot 3He cryostat

The HelioxVL is a vacuum loaded he3 cryostat. Its performance is unrivalled by any other 3He system : less than 245 mK for more than 90 hours.

Achieved using advanced sorption pump technology combined with the specially engineered 1 K condenser and 3He pot.

Quick sample change
Compact design
Low maintenance : An in-built cryopump traps contaminants so no blockages occur during operation.
Easy to use
Low vibration : The combination of cryogenic pumping and a coil condenser at 1K provides an excellent environment for vibration-sensitive measurements.

Can be combined with a magnetic sample environment:

For magnetic fields up to 18 tesla, the HelioxVL is combined with conventional magnetic environments from the IntegraTM product range.
For magnetic fields below 6T, a small magent is mounted on to the IVC tube and provides nmagnet operation in persistent mode in a transport dewar.

Specifications
System components/options
Operation
Applications

Temperature range	< 245 mK – 1.2 K. Higher temperature option available.
Cooling power	> 40 µW at 290 mK for over 10 hours
Temperature stability	± 3 mK at T<= 1.2K
Operating time at base temperature (no heat load)	> 90 hours (no applied heat load)
Liquid helium consumption (typical)	3 litres to cool the insert from room temperature to 4.2 K. 0.04 l/hr running at base temperature
3He regeneration time	Typically 30 minutes
Sample space	40 mm sample space to suit 52 mm cold bore magnet
Experimental access	24-way Fischer connector and mating plug at room temperature Nomex woven ribbon cable of 12 twisted pairs (24 wires) 0.1 mm diameter constantan wires with polyester insulation 25-way miniature D-type connector and plug on top of 3He pot

The complete HelioxVL system consists of:

An insert including the self-contained 3He dump and cryogenic pump
An external small pump for the 1 K condensing stage
The controlling electronics and software
The diagnostic wiring

Options :

A range of non-standard wiring including 24-way connector wired to 3He pot, 4-off flexible stainless steel co-ax cables wired to 3He pot, 24-way wired connector and 4-off flexible stainless steel co-ax cables wired to 3He pot and UT-85 cable wired to 1 K plate.
(External) 1K stage pumping system
Calibrated ruthenium oxide sensors on the 3He pot
High temperature option extended to 300K (zero field) or 100K (in field).

Integra systems options include:

100/150/200mm clear sample space to field centre line
Low eddy current sample holder
Manual or automatic Swedish rotator

Solutions to helium rising costs :

The HelioxVL is compatible the IntegraAC, recondensing liquid helium cryostat.

This product has been developed to significantly reduce the consumption of liquid helium by recondensing helium gas evaporated within the system, which would other wise be vented from the cryostat. This decreases the frequency of helium refills. Cryogenic systems can be kept cold continuously, even when in stand by mode, leading to greater freedom to schedule experimental time.

IntegraAC recondensing dewar compability sketch

The figure below shows the operating principle of the HelioxVL where the cryogenic cycle consists of two main phases:

In phase 1, the 3He gas, cryo-pumped by the cryogenic pump (sorb), is free to condense in the 1 K plate region of the central tube and runs down to cool the 3He pot and sample. After approximately 20 minutes most of the gas has been condensed and the 3He pot is nearly full of liquid 3He at approximately 1.5K.

In phase 2, the sorb is cooled to below 10 K and begins to reduce the vapour pressure above the liquid 3He. The sample temperature cools to its base temperature.

HelioxVL operating principle

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