A crystal μ cooler for a μ⁺μ⁻ collider

The development of a μ⁺μ⁻ collider for either an intermediate energy Higgs and t factory or multi‐TeV requires extensive μ beam manipulation and cooling. We describe some of the particle physics motivation. We also propose a cooling technique that uses a crystal with an accelerating gradient insert into a storage ring. We describe some possible beam cooling and acceleration tests.