The Clatterbridge Cancer Centre Foundation Trust
The UK currently has one low energy proton beam therapy unit at Clatterbridge Hospital, in the Wirral. The Douglas Cyclotron  unit was installed at Clatterbridge in 1984 with funds from the Medical Research Council (for neutron therapy). In 1989 funding was provided by the Imperial Cancer Research Fund and Cancer Research Campaign (now amalgamated as Cancer Research UK) and local charities, to develop the facility for proton beam treatment for tumours of the eye. This is a specialist unit built using public (and charity) money.
Currently, there is no dedicated private patient unit at Clatterbridge, but the trust has advertised on the OJEU for a joint partner to create a private patient unit. The Expressions of Interest  provided by the trust indicates that the private patient unit will have access to the low energy proton beam therapy unit:
CCO has proposed the use of space adjacent to its outpatient department which would enable access to a separate discrete entrance for separation from NHS facilities. It is expected that the facility would be outpatient focussed and offer radiotherapy, chemotherapy and proton beam therapy for ocular tumours.
Clatterbridge is currently the only provider of low energy proton beam therapy for the treatment of ocular tumours. The low energy proton beam unit at Clatterbridge was built using public money, but now the trust say that the facility will be available to private patients.