Speaker
Dr
Christoph Gabor
(Rutherford Appleton Laboratory)
Description
The Front End Test Stand FETS is the Uk's contribution to next High Power Proton Accelerators (HPPA) and is located at the Rutherford Appleton Laboratory (RAL). It is a collaboration of several institutes and universities in the UK and elsewhere in Europe and comprises of a high current H- (Penning) ion source including post acceleration, a low energy transport line (three solenoids each with Lambertson coils in x and y direction) to match the beam into a four-vane RFQ and a Medium Energy Beam Transport (MEBT) section. The input energy of the RFQ is 65keV and its output is at 3MeV. One of the projects aims is to operate the RFQ with up to 10% duty cycle (2ms, 50Hz) with currents as high as 60mA. This requires a careful layout of the Low Energy Beam Line (LEBT) and numerous emittance measurements to learn about the best parameters for injection. Challenging aspects are the high currents; a variation of space charge compensation along the matching section; inhomogeneous beam distributions; possible off-centered beams, steering effects; and a variation of input parameters e.g. caused by source instabilities and post acceleration.
An overview of the current status of emittance measurements and how important beam parameters influence the output distribution of the LEBT will be given. Simulations based on the experimental data are compared with the theoretically defined acceptance of the RFQ.
Author
Dr
Christoph Gabor
(Rutherford Appleton Laboratory)
Co-authors
Dr
Alan Letchford
(Rutherford Appleton Laboratory, Isis)
Dr
John Back
(Warwick University)
Mr
Scott Lawrie
(Rutherford Appleton Laboratory, Isis)
Dr
Zunbeltz Izaola
(ESS Bilbao, Spain)
