Accelerator group confirmed at 15:10 on Feb.
3rd, 1999, that 12-GeV proton beams were
successfully extracted through the newly
constructed fast-extraction system for the
neutrino-oscillation experiment. Beam-channel
group then confirmed that (at 16:00) extracted
beams were successfully transported through
the newly constructed beam line and had reached
a beam-position monitor placed at the location
of the neutrino-production target. In the
photograph below, position and shape of the
extracted beam are seen as the bright spot
on a beam-position monitor in the beam line.
During FY 1996, KEK started a preparatory
construction for the long-baseline neutrino-oscillation
experiment utilizing KEK 12-GeV Proton Synchrotron
as well as the Super-Kamiokande detector
(of University of Tokyo) at Kamioka located
250 km from KEK. Newly constructed facilities
comprise a fast-extraction system of the
Proton Synchrotron, a beamline which guides
the extracted beams toward the exact direction
of Super-Kamiokande to provide neutrino beam,
and a near-side neutrino detector.
This succeess in fast-extraction and beam
transport system implies that we have got
through the most difficult part and came
into the final phase of construction. Construction
and tuning of the near detector is proceeding
without delay. Tuning work on the beamline
and the near-side detector continues till
the end of March, while the first neutrino
beam coming from Tukuba will be observed
by the Super-Kamiokande. The long baseline
neutrino-oscillation experiment will officially
start in April.
 |
 |
|||
|
|
Lower sweep: Beam current in the PS ring Several pulses indicate beam bunches circulating in the ring. Upper sweep: Current of the kicker magnet After the current rise, the beam bunches are extracted and disappear in the ring |