Why do Hydrogen and Helium cannot be liquified by Linde's Method??

hydrogen and helium can be liquefied by modifications of Linde’s method. The Hampson-Linde process is particularly useful. All such processes rely on the Joule-Thompson effect, that is, the cooling of a compressed gas flowing quickly by way of a nozzle into a low-pressure chamber. The cooled air leaving the chamber then cools the gaseous air entering the JT device, then it’s compressed while being cooled and re-sent through the nozzle. However, the temperature of the gas must be lower than it’s inversion temperature before it can be liquefied this way. That is why a series of liquefied gases with higher boiling points are used to cool those with lower b.p. Each gas has a b.p. that’s below the inversion temperature of the gas that follows it in the cascade, thereby ensuring that the lower gas in the cascade can be liquefied.

H and He cant be liquified because their atomic Masses are small . second reason is that intramolecular forces are not present in helium and they cannot form covalent bond London forces are weak than inter molecular forces ,so less energy is required to overcome these forces and gas cannot be cooled.