Controlling operation of a radiotherapy device

A radiotherapy device for a delivery of a radiotherapy treatment beam, the radiotherapy device comprising:

• a beam generation apparatus that is configured to output radiation via a radiotherapy treatment beam, wherein an operation of the radiotherapy device includes use of at least one operational parameter, wherein the at least one operational parameter is heat generated at a component of the radiotherapy device, wherein the component is one of a magnetron, an RF window, an RF circulator, a cooling system or the beam generation apparatus, and wherein the radiotherapy device is configured to deliver a radiation dose to a target;
• and
• a processor configured to determine a control scheme according to at least one criterion associated with the at least one operational parameter, wherein the at least one criterion is that a predefined heat threshold should not be exceeded, and wherein the determined control scheme comprises instructions which, when implemented by the processor of the radiotherapy device, cause the radiotherapy device to:
• deliver at least a first portion of the radiation dose at a first radiation delivery rate at a first time (t1);
• and
• undergo a cool-down period, wherein during the cool-down period a second radiation delivery rate is less than the first radiation delivery rate.