Comment Suboptimal Design (Score 5, Interesting) 219
In reality, the Chinese project is definitely not make-work if they plan to do actual research.
True but a circular design for a electron-positron collider is far from the most efficient. At the energies needed to create the Higgs the energy loss caused by bending the electrons around in a ring means that the ring has to be far longer in circumference than a 'one-shot' linear collider would need to be. Worse if we find something even more exciting like Supersymmetry in our next run of the LHC starting this coming March you will never be able to increase the energy of a circular e-p machine to study it whereas with a linear collider you can extend it.
A circular machine only makes sense with heavier particles like protons but I question whether the cost savings of a single tunnel for both an e-p machine and a future proton machine will outweigh the massive increase in the cost of the magnets and accelerating cavities for the e-p machine.