Contents of talk May 2nd 2006

Y. Muraki on behalf of the LHCf

1. Physics goal 2. The BRAN detector3. The particle distribution inside the BRAN4. In case the BRAN will be located at 5th slot

(30cm Cu, 3.85cm W, 10cm W)

Our Physics Goal The exposure time is only a few hours

　 The BRAN detector

Luminosity detector in TAN

Luminosity detector in its case“Guts” of the luminosity

detector that is inserted into caseDetail view of bottom

Ionization chamber

Copper mounting

plate

Printed circuit board

BEAM

Cross section detail, parallel to beam

Case wall

copper filler

copper filler

Case wall

copper mounting

plate

Macor chamber

wall

Macor chamber

wall

Ground plane comb (in blue)

signal comb (in orange)

Ceramic printed circuit

board

Cross section detail, normal to beam

Case wallCase wall

Macor chamber

wall

Macor chamber

wall

Ground plane comb (in blue

and red)

signal comb (in orange)

Configuration of LHCf-BRAN

Particle distribution in BRAN as a function of beam center

The ratio of particles detected by the 4 　 parts of the BRAN detector

The threshold of BRAN is set at > 500 particles

　 Particle distribution of Arm #2

Particle distribution of Arm 2 The threshold of BARN >500 ptls.

Ratio of particles detected by each BRAN sensor

The position resolution of the LHCf for Arm #1

The particle distribution in BRAN for original Cu 30 cm

The particle distribution in BARN for 3.85cm tungsten (W) plate

Particle distribution in BRAN without LHCf (linear scale)

Particle distribution in BRAN without LHCf (log scale)

In the case the BRAN is set at the 5th slot

The particle distribution in BRAN for 10cm thick tungsten block is used

Summary of talks

1. The LHCf experiment can resolve the highest energy cosmic ray problems.

2. Present configuration of LHCf-BRAN can measure the beam neutral center by both detectors independently.

3. However installation of the BRAN at the 5th

slot will provide us a better result.

　 The Arm #1 beam pipe structure

The Arm #2 beam pipe structure

Position identification by the LHCf