A prototype Silicon-Tungsten electromagnetic calorimeter (ECAL) for an International Linear Collider (ILC) detector was installed and tested during summer and autumn 2006 at CERN. The detector had 6480 silicon pads of dimension 1×1 cm 2 . Data were collected with electron beams in the energy range 6 to 45 GeV. The analysis described in this paper focuses on electromagnetic shower reconstruction and characterises the ECAL response to electrons in terms of energy resolution and linearity. The detector is linear to within approximately the 1% level and has a relative energy resolution of (16.6 ± 0.1)/ E(GeV) ⊕ 1.1 ± 0.1 (%). The spatial uniformity and the time stability of the ECAL are also addressed.

One-dimensional position sensitive detector (PSD), which was used to monitor a beam position, was adapted to detect the wire displacements of the pulsed wire method (PWM). The output amplitude corresponding to the wire displacements on this PSD has showed a good linearity in a given 1mm aperture and the amplitude is very large comparing to the other sensors. The noise components generated by signal processor of the PSD and induced from the surrounding equipment and the power lines were eliminated by the bandpass digital filter. The wire sag was reduced by forcing high tension on the wire and by making the length of wire as short as possible using dampers on both ends. With these methods, the high accuracy of the PWM was obtained. The field profile of the U10 undulator in Pohang Light Source has been measured using the PWM. It is found that the results of the PWM are agreeable to that of Hall probes.

In this paper, we introduce an efficient three-dimensional magnetic field mapping system for a Deflection Yoke (DY) in Cathode-Ray Tube (CRT). A three-axis Hall probe mounted in a small cylindrical bar and three-stepping motors placed in a non-magnetic frame were utilized for the mapping. Prior to the mapping starts, the inner contour of DY was measured by a laser sensor to make a look-up table for inner shape of DY. Three-axis magnetic fields are then digitized by a threedimensional Hall probe. The results of the mapping can be transformed into various output formats such as multipole harmonics of magnetic fields. Field shape in one, two and three-dimensional spaces can also be displayed. In this paper, we present the features of this mapping device and some analysis results.

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