In 1908, on July 10th, Dutch physicist Heike Kamerlingh Onnes finally succeeded in liquefying helium (the last gas ever to be turned into liquid) in his cryogenic lab at the University of Leiden.

After a long day’s work he produced just 60 milliliters, essentially a small tea cup of this precious liquid. That special day proved to be monumental for the development of a brand new research field known now as low temperature physics.

Superconductivity was soon discovered, which in turn led to the development of the high field superconducting magnets that are currently used in all NMR systems.

A constant supply of liquid helium needed periodically to top the cryostat is crucial for the on-going low temperature research.

Since the beginning of January 2015 the cryogenic department has 5 ATL 160 liquefiers and 3 ATP purifiers.

We provide the University of Leiden 23.000 ltr liquid helium/ year.

The Cryogenic Division of LION consists of a liquid helium production unit as well as an automatic liquid nitrogen filling plant.

The liquid nitrogen supply

On an annual basis, approximately 200,000 liters of liquid nitrogen is currently being issued by the department; It is not self-produced but directly involved with the company Linde AG. A storage tank of 15,000 liters is available for this purpose. The liquid nitrogen is distributed in special 160 liters of vessels, which are equipped with a level reading and a pressure build system. There are about 50 of these barrels available. Given the purchase price of liquid nitrogen, it makes no sense to produce this yourself.

The helium supply

Since liquid helium is important for low temperature research, careful care is taken. It is a scarce and therefore expensive product. The gas released by evaporation is thus collected in a large gas bag and stored therefrom under high pressure in 6 cylinder packages at a maximum pressure of 160 bar.

About 23,000 liters of liquid helium is produced annually. To realize this, we have 5 ATL160 liquifiers and 3 ATP30 purifiers (to clean the gas) 160 represents the contents of the vessel in which the liquid is produced. From these vessels, the liquid helium is transferred into transport vessels (the so-called Dewars) of 50, 100 and 200 liters.

Support and information on the use of cryogenic fluids for safety. Especially new students get extra attention.

For these primary services, an automated administrative program has been set up, of which anyone who needs helium or nitrogen can use their own "user number" and "password". The supply of cryogenic liquids takes place primarily for internal research.

The ten commandments of the LION Cryogenic Department

1. Are you new to the Cryogenic Department? Introduce yourself to the employees and ask for the correct procedures regarding the laboratory.
2. Safety First: do not handle any cryogenic liquids carelessly. If your skin comes in contact with the liquid, it will cause a serious freezing effect equivalent to burning. Always use protective gear.
3. In case of freezing: wash the affected area thoroughly, or shower. Do not remove clothing. In case of inhalation: go outside to get fresh air and if necessary, get insufflation. In doubt: warn a doctor.
4. Please proceed in the correct manner with the helium dewars: dewars should not be completely empty – this is to avoid warming up.
5. The cryogenic dewars are the property of the department. Take care of them, do not write on them or put stickers on them. Do not change the connections on the dewar.
6. Always connect heliumdewars to the heliumgas return line and make sure that the wheels are blocked.
7. Is your set up no longer being used? Always close the valve to the heliumgas return line – never rely on the one-way-valve!
8. If you order liquid helium this should be done at least three days in advance.
9. Work in a conscientious way to avoid losses. Helium is very scarce and therefore an expensive product. The more you waste the higher the costs.
10. In case of doubt with any of the procedures, please ask for assistance from one of the employees of the Cryogenic Department.

De tien geboden van de LION Cryogene Afdeling

1. Nieuw in de Cryogene Afdeling? Maak eerst kennis met de medewerkers en vraag naar de juiste procedures die hier gelden.
2. Werk veilig: ga nooit nonchalant om met cryogene vloeistoffen. Aanraking met de huid geeft ernstige bevriezingsverschijnselen equivalent aan verbranding. Gebruik beschermingsmiddelen.
3. In geval van bevriezing: spoelen met veel water of afdouchen, geen kleding uittrekken. In geval van inademen: zorg voor frisse lucht en zonodig beademing. Waarschuw bij twijfel een arts.
4. Ga op de juiste wijze om met heliumvaten: maak ze nooit te leeg en voorkom daarmee opwarming.
5. De cryogene vaten zijn eigendom van de afdeling. Hou ze netjes, beschrijf en beplak ze niet, verander nooit eigenmachtig aansluitingen.
6. Sluit heliumvaten altijd met geopende afsluiters aan op de verdampingsleiding en zorg dat ze op de rem staan.
7. Is uw opstelling niet meer in gebruik? Sluit altijd de afsluiter naar de verdampingsleiding en vertrouw nooit op de aangebrachte terugslagklep!
8. Bestellingen van vloeibaar helium altijd minimaal drie dagen van tevoren doorgeven.
9. Werk bewust en voorkom verliezen. Helium is een schaars en daarmee duur product. Verliezen bepalen mede de heliumprijs voor u als gebruiker.
10. Bij twijfels en vragen: raadpleeg een medewerker van de Cryogene Afdeling.

You can order helium at the cryogenic department or go to:

https://cryo.physics.leidenuniv.nl and log in with your ULCN account.

Choose the right group/ set up and place your reservation.

REMEMBER: order 3 day’s ahead.

As soon as your reservation is ready we will place the number of the dewar you can take in your reservation (Vessel Nr).