TY - JOUR
T1 - GPS survey in long baseline neutrino-oscillation measurement
AU - Noumi, H.
AU - Ieiri, M.
AU - Inagaki, T.
AU - Hasegawa, T.
AU - Katoh, Y.
AU - Kohama, M.
AU - Kurodai, M.
AU - Kusano, E.
AU - Maruyama, T.
AU - Minakawa, M.
AU - Nakamura, K.
AU - Nishikawa, K.
AU - Sakuda, M.
AU - Suzuki, Y.
AU - Takasaki, M.
AU - Tanaka, K. H.
AU - Yamanoi, Y.
PY - 2004/10
Y1 - 2004/10
N2 - We made a series of surveys to obtain neutrino beam line direction toward SuperKamiokande (SK) at a distance of 250 km for the long-baseline neutrino oscillation experiment at KEK. We found that the beam line is directed to SK within 0.03 mr and 0.09 mr (in sigma) in the horizontal and vertical directions, respectively. During beam operation, we monitored the muon distribution from secondary pions produced at the target and collected by a magnetic horn system. We found that the horn system functions like a lens of a point-to-parallel optics with magnification of approximately - 100 and the focal length of 2.3 m. Namely, a small displacement of the. primary beam position at the target is magnified about a factor - 100 at the muon centroid, while the centroid position is almost stable against a change of the incident angle of the primary beam. Therefore, the muon centroid can be a useful monitor of the neutrino beam direction. We could determine the muon centroid within 6 mm and 12 mm hi horizontal and vertical directions, respectively. This means that the neutrino beam direction could be controlled within 0.03 mr and 0.06 mr (in sigma) in the horizontal and vertical directions, respectively. We confirmed the beam direction with the neutrino distribution reconstructed at the near detector in KEK.
AB - We made a series of surveys to obtain neutrino beam line direction toward SuperKamiokande (SK) at a distance of 250 km for the long-baseline neutrino oscillation experiment at KEK. We found that the beam line is directed to SK within 0.03 mr and 0.09 mr (in sigma) in the horizontal and vertical directions, respectively. During beam operation, we monitored the muon distribution from secondary pions produced at the target and collected by a magnetic horn system. We found that the horn system functions like a lens of a point-to-parallel optics with magnification of approximately - 100 and the focal length of 2.3 m. Namely, a small displacement of the. primary beam position at the target is magnified about a factor - 100 at the muon centroid, while the centroid position is almost stable against a change of the incident angle of the primary beam. Therefore, the muon centroid can be a useful monitor of the neutrino beam direction. We could determine the muon centroid within 6 mm and 12 mm hi horizontal and vertical directions, respectively. This means that the neutrino beam direction could be controlled within 0.03 mr and 0.06 mr (in sigma) in the horizontal and vertical directions, respectively. We confirmed the beam direction with the neutrino distribution reconstructed at the near detector in KEK.
KW - Beams
KW - Global Positioning System
KW - Neutrinos
UR - http://www.scopus.com/inward/record.url?scp=8344275248&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=8344275248&partnerID=8YFLogxK
U2 - 10.1109/TNS.2004.836042
DO - 10.1109/TNS.2004.836042
M3 - Review article
AN - SCOPUS:8344275248
VL - 51
SP - 2245
EP - 2249
JO - IEEE Transactions on Nuclear Science
JF - IEEE Transactions on Nuclear Science
SN - 0018-9499
IS - 5 I
ER -