FAQs about Helium

THE HELIUM SERMON (V.25.06.2022 with security update) 


Praised be the helium, the gas of the gases, the juice of the juices (at T=4.2K), the elixir of life of the physicists and the bread of the gas suppliers!

With what we would be already in the middle of the sermon. Due to numerous inquiries from the Internet first the FAQs for the non-experts : 

Q : I need helium for my children's birthday / tethered balloon experiments with radio antennas / model zeppelin / as Mickimouse imitator.... . Where can I get it ?
A : The companies Air-Products, Air-Liquide, AGA, Linde, Messer Griessheim (the list does not claim to be complete) supply helium for normal requirements in the form of "balloon gas" partly in special small bottles including pressure regulator and other accessories. In Austria the AGA agency is in Vienna Schwechat, Messer Griessheim is in Gumpoldskirchen in the south of Vienna. Attention : for these bottles there is usually a hefty rent to pay, so order on time and return the bottles as soon as possible. 
Q : How much does helium cost ? 
A : In this country helium is not cheap. The price for one cubic meter of balloon gas is in the order of 100 öS (14 DM). For current prices, please contact the above companies. 
Q : Is helium dangerous ? 
A : If you don't inhale helium and want to play Donald Duck in a squeaky voice (DON'T DO THAT !!! there have been deaths with such shenanigans) there are actually no problems with the gas, as long as all experiments are done only in well ventilated rooms, preferably outdoors. 
Q : Are helium gas cylinders dangerous ? (Children like to ask : are those atomic bombs standing around ?) 
A : No, atomic bombs look different. If you want to see them, you can see models at the National Atomic Museum in Los Alamos. However, all gas cylinders falling over are dangerous (weight of a big cylinder about 100 kg), especially if the protective cap is not screwed on. Gas cylinders should always be chained to walls. Anyone who drives gas cylinders around with the valve unscrewed is a potential suicide. If the valve of a full gas cylinder breaks off, you can assume that the cylinder will behave and act like a torpedo. This is no joke, the Arsenal in Vienna supposedly does an impressive test on this subject once a year. 
Q : What else do I need to be aware of in my tethered balloon experiments ? 
A : In the vicinity of airfields, be sure to contact airspace control (in Austria, Austrocontrol in Vienna). On modern radars you can see if you are looking out of the skylight of your house. If they let a balloon rise in controlled airspace, they will probably shoot first and then ask. In any case there is a hefty fine and/or the "Hefn". 
Q : Helium is so expensive, can't I use hydrogen for my balloon ? 
A : Hydrogen may be cheaper than helium and has more buoyancy, but it is extremely dangerous to handle (see "Fire of the Hindenburg"). Best FINGER AWAY FROM HYDROGEN, because only one mistake and BOOM !!! The problem is that hydrogen is self-igniting, i.e. pressurized, escaping hydrogen becomes HOT in contrast to "normal gases" which become cold during expansion. Exploding gas cylinders can be compared with a 200 kg bomb. 
Q : Can I borrow a can of liquid helium from you for my birthday party, I will also pay you for the gas ? 
A : No, balloon gas is cheaper and more practical. If you absolutely want to pan with cryogenic liquids, get liquid nitrogen. But CAUTION, liquid nitrogen is also NOT a toy and glitches as a hazardous material. You can hear details in Prof. Steiner's seminar on safe handling of cryogenic liquids. 
Q : What the hell do you need liquid helium for ? 
A : liquid helium is cold, very cold even (-269 degrees Celsius or 4.2 degrees Kelvin, it can hardly be colder) and therefore the juice of the juices for every true physicist :-)) 
For the "experts" : General information on how to use helium sparingly and how I avoid becoming a helium rogue. 


I believe in the economical use of helium, because helium is money, ALSO MY MONEY, and that's why I will not waste it, AMEN !!! 

The helium - principle at the fke :

´Liquid He is delivered in cans from the cryogenic plants, evaporating He gas is first collected in the basement in a 10m3 balloon and from there pumped into steel cylinders and returned to the cryogenic plants. In recycling operation this costs 16 ATS /l. 

Consumption statistics :
1995 : 12300 liters 
1996 : 12016 liters 
1997 : 9942 liters  
1998 : 17138 liters  
1999 : 12870 liters  
2000 : 8895 liters  
2001 : 7162 liters 

Which cryostat consumes how much in full operation?

(for the non-experts: Cryostats are "thermos flasks in which we perform our experiments at low temperature) 

Black bath cryostat 120 l / week = 0.7 l/h  
Blue bath cryostat 150 l/ week = 0.9 l/h  
STM Cryostat 80 l/ week = 0.5 l/h  
Cryoflow PL 2.0l /h 80 l / week (5 working days a 8 hours)  
Cryoflow Nicolet 3.7 l/h 148 l/week (5 working days a 8 hours) 

What do we learn from this ?

Cryoflows are not small consumers !!! 
Cryoflows load the recycling system up to the edge of the capacity !!! 
On the subject of losses :
The operation does not go loss-free even in the ideal case, to absorb possible additional breakdowns, a maximum of 15% loss is calculated into the price. (constant point of contention on the He-User meetings !). Higher losses are to be paid fully and cost 150 öS per liter. Losses have various causes e.g. there are : 

Losses due to real breakdowns :

Compressor leaks (a real problem, only noticeable when 2 to 3 weeks massively too little helium comes back) 480 l (= 4 % at the last breakdown)
Vacuum breakdown in the cryostat and as a consequence a "pseudoquench" 50 l (0.3 %)
He-can overturned out of anger 100 l (only 0.6 %, gas loss but 100.000 öS damage for a new can) 
Magnetic quench (often due to stupidity of the user) 50 l (0.3 %) 
Loss statistics 1995-2000 :
Loss 1995 : 6.5% optimal 
Loss 1996 : 12 % because of compressor breakdown. (about 8% without the breakdown) 
Loss 1997 : 16 % without the breakdown !!! -> no good performance but boundless sloppiness !!! 
Loss 1998 : 11 % (because of excessive bolometer use ?) 
Loss 1999 : 14 % :-(( !!!!! there are not so many bolometers in whole Vienna !!!! 
Loss 2000 : 16 % (I don't even want to know who did it, because otherwise he will get the bill for the gas loss) !!!! 
Loss 2001 : 19% = 20041 ATS !!!! 
A loss of 16% > 15% and because 1l helium = 150 ATS if not recycled means 12000 ATS additional and unnecessary He costs for 1997 and 20041 ATS for 2001!!!!

The horror scenario :

What if there is a breakdown (compressor, vacuum breakdown, quench) AND He sloppiness ? 

Consumption 15000 l/year (=225000 ATS, part of which is subsidized by other means) 
Basic loss 8% 
Loss due to sloppiness 8% (as in 1997) 
Operational accident 4 % 
Total loss 20% -> to be paid 5% = 112000,- ATS !!!! which corresponds to 25% of the oDot. 
-> Since we can declare bankruptcy in such a case, the losses MUST be pushed below 10%. 

Where do the losses come from ?

Basic losses 
Losses on the high pressure side (approx. 3%) 
Siphon cold blowing : nevertheless only (approx. 1 l / 40 l filling = 2.5 % measured) 
Handling losses approx. 1% 
Total = 6.5 % (1995) 
Bolometer filling (do not hang on recirculation for technical reasons) = 2% (since 1996) 
Total 8% (suggestions for reduction welcome) 
All other losses (8%) are caused only by user sloppiness ! 

Latest preventive measures :
Recently, our technical department controls by means of the new gas meter the ratio of recirculated gas quantity and the gas quantity in the cylinders. This way compressor leaks can be detected earlier. Nevertheless, this is no reason to feel safe, because remember : 

Many small leaks add up to one big leak !!!

The helium sins:(everything already happened, nothing lied, nothing invented): 

Felony #1 : open cans
the whole return is open, the balloon (10 m3) of the recycling plant is thus immediately empty the exhaust steam of all cryostats is blown (50 l per day, at least 100 l on weekends)
water + ice gets into the can : this can never be taken out again, the insulation gets bad, ice clogs the lifters (old IBK can) and Prof. Steiner gets (rightly) a fit. 
open jugs are often in the following forms : 

Open lines (valve open, plug missing) (rather rare) 
Return line is connected, but open hose is in the corner (very popular !) 
No plug, or plug is searched for hours, meanwhile jug is open and finally forgotten.
Can is left open because "the can is empty anyway, then why the plug ?" 
Balloon dismantled by someone (because too lazy to look for own balloon), valve for balloon is open. 
capital crime #2 : open return lines

The simple mistake (very rare) : 

Open feedback lines and open blind flanges 


The typical mistake (common) :

The Cryo-Flow siphon inlet is left open after operation ,or in operation while the return line is connected !!!!  This generates huge losses via the open  inlet as the cryoflow exhaust steam is about 2-4 l He / hour. 
Open bath cryostats (siphon or top flange) : Thus, the recirculation is open (rather seldom because well visible by backward turning He-meter) 

Cryoflows / Bolometers are basically not at the return because "not worth it anyway because of the little helium consumption". 
Remember: self-closing connectors are not installed everywhere! 

Smaller, but enormously adding up helium sins

Fill the cryostat first, then search for hours for a plug for the can / cryostat. 
Pull out siphon when can / cryostat is under pressure -> high gas loss because cold gas escapes 
feedthroughs are not closed (return line is under overpressure) 
No O-rings in the feedthroughs ("oh there should be an O-ring in there ? Ahh that's what these grooves are for, I've always wondered why....") or completely rotten O-rings in the feedthroughs. (Chewing gum seals are also tight, but should not become the fke standard). 
The desert handling of the lifters : lifters are expensive and have a delivery time of months because they are mostly special productions 
Cans that are not connected to the return system blow off into the air (and are also a safety risk because of the high pressure) 
The attitude : "in America we filled the cryostats until the liquid helium trickles down on all sides nice and evenly and above all the healing helium spraying out at the top looks so nice like a flower. This is why it is called blooming...".   !!! THIS IS NOT AMERICA !!!! 
Also not good for trouble-free He operation : the mess in the lab ! 

Finally I am tired of the following things : 

Missing blubber 
Missing plugs 
Missing gaskets + worn and scattered o-rings 
Irreplaceable special parts (flanges) have disappeared or are somewhere misappropriated 
Feed-through and flange parts are hanging on some lifters in other laboratories or are even taken to the deep bunker U4 
etc etc etc.... 

Once and for all applies :  
We are NOT in America but nevertheless also not on a communist collective farm ! 

Flange parts, blubber etc. are not collective property and therefore remain in the respective laboratories. 
If such special parts are missing : buy them or have them made (I have been saying this for 3 years) 
Not finding a part in your own mess immediately does NOT entitle you to borrow it in the secondary lab !!! 
The persons concerned have to be informed about the borrowing process so that they do not have to look for the borrowed part unnecessarily. 
My lab is not a spare parts store ! 
A mess leads to a waste of (especially my) working time and to a considerable disturbance of the laboratory operation (e.g. lifting on the weekend was not possible because of missing clamping ring and the cryostat thawed). 

How do I make myself particularly unpopular with Prof. Steiner, our liquid-He supplier ?

Good chances on eternal cursing has: 
Who lets helium cans stand forever in the laboratory, so that they become nicely warm before they are returned. In this way you need 30 liters of helium extra and one hour extra time to fill the cans again.  You are sure to be cursed by Steiner and all his technicians. 
Who inflates helium cans with STICKSTOFF when overheating. Then nähmlich nitrogen ice forms in the cans and to get that out again......  This part is best explained to you by Steiner personally. But take a steel helmet and a large pack of Valium with you. The helmet is for you, the Valium iffor Prof. Steiner. 3 crates of beer for the technicians may ensure your survival in case of guilt.... 
Who needs 200L helium immediately and absolutely tomorrow morning. Jugs have to be filled and transports have to be organized. Once an emergency may pass as an excuse. In case of repetition, the technicians will probably ...(Unsuitable for publication). !! 

Is there possibly absolution from my helium sin ? :
From the eternal damnation with 4.2K (-269 degrees Celsius) can be saved only who :

Swears that he has understood that applies : He = $$$$$. 
Swears that he always pays attention to open regressions etc. in the future. 
Swears that in the future he always keeps order in the laboratory and does not hide the flange parts of the others. 
Swears that he will confess sins committed immediately, so that the He-responsible persons do not have to search for leaks for weeks. 
Swears that he will not offend the cryogenic plants, because we have to pay for such actions ALL TOGETHER. 
Finally and at last : safety and who is allowed to do what ?

Note: of course, the He system is as safe as possible (pressure relief valves, etc.) But anyone can make a mistake and if the previous user of the jug or the cryostat makes a mistake and you are not particularly careful yourself, it can be really bad.....

Therefore applies : 

First of all : the visit of Prof. Steiner's cryo-training is mandatory for all newcomers !!! 
every He user checks always and everywhere at every jug (even if he doesn't need the jug and just runs into it by chance), that the jug is REALLY on the exhaust. The official state of the jug is: the exhaust valve is open 
The self-closing one is plugged WHOLE on it 
The valve to the balloon is open 
Gloves and goggles are always worn when handling helium / coolants 
When changing the He-bottles in the recycling plant it is absolutely necessary to wear ear protection and face protection.  (again and who does not believe ask the Steiner and his people: If such a hose bursts at 200 bar, it REALLY tears the ears from your head !!!! PUT ON HEADPHONES !!!  NO EXCUSES !!!) 
Reminder : Nitrogen tanks are only to be moved in pairs, especially on the road ! 

What to do if an accident occurs, especially if coolant leaks? A typical accident is e.g. that the siphon freezes, He leaks and fogs the laboratory.  Fogging is a special problem, because it takes away the visibility for targeted actions and there is also a danger of frostbite. In such cases the rule is : 

Immediately get out of the gas mist and open all exhaust valves and pressure relief valves (this may reduce the risk of explosion). IMPORTANT : in the event of a malfunction, thoughts of saving money are completely out of place, your own safety comes first. 
It is much worse if something dubious happens and you do not know what is going on (loud noises in the can / cryostat, sudden huge exhaust steam, etc.) In such cases, the following applies to the normal user: First act, then think, namely :

Immediately tear open ALL exhaust valves and pressure relief valves (can + cryostat) NO MATTER WHETHER YOU THEN BLEAVE THE HELIUM  INTOTHE AIR OR NOT 
Ensure open escape route 
Assess the danger and then look for the cause but only in pairs !!! 

It is very bad if you knock over a cryo-can out of anger or similar. In cast this happens

For He jugs : run 
For LN2 cans: run faster (in rare cases it may make sense to try to open the valves, but never to reach into the cold gas flowing out!) 
!!! Danger of frostbite, danger of asphyxiation, SERIOUS danger of explosion !!! 
Note : It is useless to try to put the cans back in place, because the cans are heavy. This is especially true for the nitrogen cans (about 300 kg). 

Who is allowed to operate badcryostats self-responsible ?
Permits for self-responsible work with bath-cryostats at the fke are given ONLY by juergen.smoliner@tuwien.ac.at ! Self-responsible working with badcryostats is currently allowed for : 

All others work only under the presence of a "He-Seniors" (3 times cryostat operation does not entitle to self-responsible work). The VTI looks simple, but is very insidious in terms of occupational accidents and He-disasters. Whoever thinks he can cool down a bath-cryostat "just like that" is welcome to try it, but only on a Cryostat which will not be needed by anybody for the next 4 weeks !!! 

Who is allowed to operate Cryoflows self responsible ?
ONLY Masiar Sistani and Werner Schrenk train and issue the permits. 

Who is allowed to tinker with the recycling plant including return lines ?
ONLY the technical department and persons SPECIFICALLY trained by the technical department, and WITHOUT EXCEPTION. 

In case of doubt : FIRST ask / call THEN act ! 

There is no shame in calling me, Masiar, Werner or the technicians on weekends or late at night. Better to call once too much than to freeze your fingers or break something ! 

Do not forget: Never work alone and especially not ,when handling coolants!  
gez. J. Smoliner, (as Helium-Oberguru on duty)