The cost of days without runs

[jmc2000]

Today, there's a communication problem with the cryogenics whcih means there's no beam for 1 1/2 days. I don't think this would have happened if they had doubled up with a backup, but only if it was economically feasible to do this on the least reliable and least espensive parts.

So does anyone know how much money a failure like this costs?

[Bornerdogge]

Hard to guess... It is direct cost due to the repairs or indirect cost due to the inactivity?

[pcatom]

... a lot ...

[Kasuha]

Magnets don't have to be powered.
Cryo must be running, although at reduced performance. Letting magnets warm up would mean two months waiting till they cool down again.
Most control systems stay powered, too but compared to the two above it's nothing.

[jmc2000]

Hard to guess... It is direct cost due to the repairs or indirect cost due to the inactivity?

Inactivity mainly, but also having to spend money on people's time bringing the system back to where it was. During inactivity, people can manage their work to compensate, whereas the cost of people's time during the recovery can't be managed. It must be a fascinating discipline in itself working out which parts of the LHC are worth duplicating based upon the expected cost involved for it to fail over the lifetime of the LHC.

[Bornerdogge]

Isn't it possible to take advantage of this recovery time to work on some other independent parts of the machine?

For example right now they are performing "rf interlock tests" while the cryo is recovering...