How many liters of gas does 1 liter of liquid helium expand to?

The correct answer is that 1 liter of liquid helium expands to approximately 700 liters of gas when it evaporates. This dramatic expansion is due to the properties of helium as a gas compared to its liquid form. At room temperature and atmospheric pressure, the gas occupies far more volume than the liquid.

Liquid helium exists at extremely low temperatures (around -269°C or -452°F). When it warms up and transitions to a gas, the helium atoms, which are closely packed in the liquid state, spread out significantly in the gaseous state. The factor of expansion is substantial, around 700 to 1 for liquid helium compared to its gaseous form.

This understanding is crucial for safety in MR environments, particularly regarding cryogenics and the management of helium resources in MRI systems. It highlights the importance of having adequate ventilation and safety systems in place to handle the large increase in volume if liquid helium leaks or is accidentally released.