| P. Ausset, S. Bousson, D. Gardès, A.C. Mueller, B. Pottin, I.P.N., 91406, Orsay, France,
R. Gobin, CEASaclay, 91191, Gif sur Yvette, France,
G. Belyaev, I. Roudskoy, ITEP, Moscow, Russia |
High Power Proton Accelerator (H.P.P.A.) projects are
being proposed in fundamental and applied physics
research: radioactive beam production, neutron sources,
neutrino factories and transmutation. The front end design
of these accelerators is based on a high intensity ion
source (several mA up to 100 mA), followed by a Radio
Frequency Quadrupole (R.F.Q.) to accelerate protons at
several MeV. Finally the beam energy is increased up to
10 MeV or more by a Drift Tube Linac (D.T.L.).
Among the parameters needed to be measured for beam
control, monitoring and halo formation prevention, the
transverse beam profiles are the most difficult to obtain.
The large expected specific energy deposition in any
interceptive monitor can lead to the destruction of the
sensor and in addition to an appreciable amount of
radiation production. Therefore traditional multi-wires
chambers and wire scanners are not usable under too high
duty factor pulsed-beam operation and obviously
continuous beam operation.
A very attractive phenomenon is the production of
visible light by the proton beam-background or additional
gas interaction. Transverse beam profiles of the
“S.I.L.H.I.” E.C.R. proton source (95 keV, 100 mA) have
been measured. However, several difficulties emerge to
explain the difference shape between the transverse beam
profiles deduced from the elementary observation of the
emitted light by a C.C.D. camera, a grid profiler (low
duty cycle operation) and a residual gas profiler,
respectively. More sophisticated measurements using the
Doppler effect have been brought into operation to
determine the energy and the spatial extension of the
different components of the beam (H+, H2
+, H3
+). |
