Minutes of E362 FD weekly meeting
                             
Sep-3-1996, 19:00 - 22:00, R307,
Present:K.Nakamura,Y.Oyama,T.Ishida(KEK),K.Nishikawa,T.Kobayashi,T.Chikamatsu,
        A.Sakai,Inagaki(INS),S.Aoki(Kobe),K.Maruyama(Tohoku),M.Etoh(Tokai),
        M.Nakamura(Niigata)

(1)scintillation fiber(Etoh)
 This week, Etoh, Sakai and Aoki succeeded to read CCD camera data by
ADC which was operated from a workstation via VME module. Sakai displayed
the pictures recorded by the CCD on a CRT and also printed out them.
 We have a small problem on the frequency of the clock generator and
we can see only one half of all view of one picture recorded by
CCD camera. We expect that this problem can be solved easily.

(2)muon chamber(Chikamatsu)
 Chikamatsu reported on the progress of the gas leak test of the muon chambers.
He completed the measurement of 20 modules out of 33. He expected that the gas
leak test will be finished by September 20. From September 24, they will work on
removal of the electronics from the chambers. They also planned to construct
a gas circulation system by December.
 Chikamatsu also presented the preliminary result on the gas leak test.
The average leak rate was found to be 0.64cc/min and the total leak
of the muon chamber system is expected to be 410cc/min. We must study how
to remove the gas from the experimental hall. It was suggested that we
can ask to the Tomoe people about the gas removal system.

(3)tension measurement of the wire of the muon chamber(Inagaki)
 He made a tension measurement system for the wire of muon chambers.
The principle of the measurement is that the tension of the wire can
be calculated from resonant frequency which maximize oscillation of the
wire. Variable frequency of magnetic field are applied around the wire
and induced current are measured. The frequency which induce special shape
in the time variation of the current corresponds to the tension of the wire.
He measured 3 chambers (= 24 wires) and all of the wires shows the correct
tension values. It takes about 10 mins for the measurement of 1 module. 

(4)muon beam monitor system(Maruyama)
 Maruyama reported on a new idea about the read out of the muon beam monitor
system. In the old system, 1cm*1cm ionization chamber cells are arranged
in two dimensional, and the signal of each cell are summed over x direction
and over y direction. We can record only the sum of the signals and cannot
record the signal from each cell because number of the channels are too
large. In the new system, the cell size is 5cm*5cm and the read out of
the signal is cell by cell basis. He presented that the new configuration
is better for the expected beam structure in our experiment and we can
easily look for the central position of the beam.

(5)identification of electron neutrinos (M.Nakamura)
 He presented a measurement of electron neutrino fraction
in the muon neutrino beam. He visually scanned 20 electron neutrino events
and 100 muon neutrino events. He examined multiplicity of the scintillation
fiber detector and energy deposit in the lead glass counter, and concluded
that both of these information are needed to identify electrons from electron
neutrinos with high efficiency. He presented that 8/11 of charged current
interaction with electron energy larger than 250MeV can be clearly identified
as electrons whereas only 5 events out of 100 muon neutrino events are
possibly misidentified as electrons. Using this strategy, the limit
for the electron neutrino fraction will be set as 7% in the worst case,
and ~2%, possibly. More quantitative analysis is needed.

(6)Others
 The prototype of the aluminium water container of the water/SCIFI detector
will is ordered.
 We searched for Memory buffer modules for the muon chamber (and enough
number of the modules are successfully found after this meeting).

						Y.Oyama