Showing papers by "Takahiko Kondo published in 2005"

Beam tests of ATLAS SCT silicon strip detector modules

Abstract: The design and technology of the silicon strip detector modules for the Semiconductor Tracker (SCT) of the ATLAS experiment have been finalised in the last several years. Integral to this process has been the measurement and verification of the tracking performance of the different module types in test beams at the CERN SPS and the KEK PS. Tests have been performed to explore the module performance under various operating conditions including detector bias voltage, magnetic field, incidence angle, and state of irradiation up to 3×1014 protons per square centimetre. A particular emphasis has been the understanding of the operational consequences of the binary readout scheme.

Application of Cu-polyimide flex circuit and Al-on-glass pitch adapter for the ATLAS SCT barrel hybrid

Abstract: We applied the surface build-up Cu-polyimide flex-circuit technology with laser vias to the ATLAS SCT barrel hybrid to be made in one piece from the connector to the electronics sections including cables. The hybrids, reinforced with carbon–carbon substrates, provide mechanical strength, thermal conductivity, low-radiation length, and stability in application-specific integrated circuit (ASIC) operation. By following the design rules, we experienced little trouble in breaking the traces. The pitch adapter between the sensor and the ASICs was made of aluminum traces on glass substrate. We identified that the generation of whiskers around the wire-bonding feet was correlated with the hardness of metallized aluminum. The appropriate hardness has been achieved by keeping the temperature of the glasses as low as room temperature during the metallization. The argon plasma cleaning procedure cleaned the contamination on the gold pads of the hybrids for successful wire bonding, although it was unsuccessful in the aluminum of the pitch adapters.

Test of ATLAS SCT barrel modules with Nd:YAG laser

Abstract: As a part of the quality assurance procedure of the ATLAS SCT (Semiconductor Tracker) barrel modules, the response of the microstrip detector is measured by injecting focused Nd:YAG laser at each strip. The test is sensitive to sensor originated problems and a cross check to the results obtained from the electrical tests performed with the test pulse system implemented in the readout ASICs. Combining these results with the probing results obtained by the silicon sensor manufacturer, we verified the reliabilities of these tests and classified the type of defects for overall performance evaluation of the modules.

Novel p-stop structure in n-side of silicon microstrip detector

Abstract: In order to suppress the high electric field at the edge of the p-stop structure, a novel p-stop structure with DC field-plate was proposed. An n-in-n detector with the novel p-stop structure showed no onset of microdischarge, before and after proton irradiation of fluences of 3×10 13 and 3×10 14 p/cm 2 .

Design and test of a prototype silicon detector module for ATLAS Semiconductor Tracker endcaps

Abstract: The ATLAS Semiconductor Tracker (SCT) will be a central part of the tracking system of the ATLAS experiment. The SCT consists of four concentric barrels of silicon detectors as well as two silicon endcap detectors formed by nine disks each. The layout of the forward silicon detector module presented in this paper is based on the approved layout of the silicon detectors of the SCT, their geometry and arrangement in disks, but uses otherwise components identical to the barrel modules of the SCT. The module layout is optimized for excellent thermal management and electrical performance, while keeping the assembly simple and adequate for a large scale module production. This paper summarizes the design and layout of the module and present results of a limited prototype production, which has been extensively tested in the laboratory and testbeam. The module design was not finally adopted for series production because a dedicated forward hybrid layout was pursued.