Vinokurov, N.A. Parkhomchuk, V.V. Skrinsky, A.N. JACoW Publishing Geneva, Switzerland 2226-0374 978-3-95450-218-9 10.18429/JACoW-COOL2019-TUY01 English 26-28 TUY01 electron cavity gun collider linac Contribution to a conference proceedings 2019 2019-11 https://doi.org/10.18429/JACoW-COOL2019-TUY01 https://jacow.org/cool2019/papers/tuy01.pdf New projects of high-energy hadron colliders could be improved significantly using electron cooling technique. But the source of high-current relativistic electron beam appears to be a technical challenge. Indeed, intrinsic energy limitations of high-voltage DC accelerators lead to necessity to use not static, but vortex, electrical field for acceleration. Induction and radiofrequency (RF) accelerators just use such field. Moreover, to keep small enough damping times at high energies, it needs to increase electron peak current to tens of amperes. The feasibility of RF energy recovery linac (ERL) for electron cooling is discussed. The ERL of the Novosibirsk free electron laser facility is used as a reliable prototype.