M. Yamada

Bio: M. Yamada is an academic researcher from University of Tsukuba. The author has an hindex of 1, co-authored 2 publications receiving 6 citations.

Characteristics of the irradiated Hamamatsu p-bulk silicon microstrip sensors

Abstract: Microstrip silicon sensors with p-bulk and n-readout are investigated as a radiation hard device for the Super LHC experiment. We evaluated the radiation hardness of the sensors fabricated by Hamamatsu Photonics through irradiation with 70-MeV protons up to the fluence of 5 × 1015 1-MeV n eq /cm2 and with 60Co γs at a rate foreseen at the Super LHC. The strip isolation and punch-through properties are characterized in detail. Various strip isolation structures, p-stop, p-spray and both combined, are examined. The results are compared among commercially available MCZ and two types of FZ wafers.

Interstrip characteristics of n-on-p FZ silicon detectors

Abstract: We report on the measurement of interstrip parameters of p-type silicon strip sensors which we are developing in a large collaboration to be used in a future tracker for the LHC upgrade. We measure on test structures with about 1 cm long strips the interstrip resistance, interstrip capacitance (at 1 MHz) and punch-through protection both pre-rad and after irradiation with 70 MeV protons to a fluence of 1.5×10^13 p/cm^2, corresponding to about 1 MRad, from prototyping runs with Hamamatsu Photonics and Micron Semiconductors. We report the values for a variety of isolation scenarios of p-stops, p-spray and a combination of both.

The ATLAS Experiment at the CERN Large Hadron Collider

Abstract: This paper describes the ATLAS experiment as installed in i ts experimental cavern at point 1 at CERN. It also presents a brief overview of the expec ted performance of the detector.

Testing of bulk radiation damage of n-in-p silicon sensors for very high radiation environments

Abstract: We are developing n+-in-p, p-bulk and n-readout, microstrip sensors, fabricated by Hamamatsu Photonics, as a non-inverting radiation hard silicon detector for the ATLAS tracker upgrade at the super-LHC (sLHC) proposed facility. The bulk radiation damage after neutron and proton irradiations is characterized with the leakage current, charge collection and full depletion voltage. The detectors should provide acceptable signal, signal-to-noise ratio exceeding 15, after the integrated luminosity of 6000 fb−1, which is twice the sLHC integrated luminosity goal.

Development of Radiation Hard ${\rm N}^{+}$ -on-P Silicon Microstrip Sensors for Super LHC

Abstract: Radiation tolerance up to 1015 1-MeV neq/cm2 is required for the silicon microstrip sensors to be operated at the Super LHC experiment. As a candidate for such sensors, we are investigating non-inverting n+-on-p sensors. We manufactured sample sensors of 1 times 1 cm in 4" and 6" processes with implementing different interstrip electrical isolation structures. Industrial high resistive p-type wafers from FZ and MCZ growth are tested. They are different in crystal orientations lang100rang and lang111rang with different wafer resistivities. The sensors were irradiated with 70-MeV protons and characterized in views of the leakage current increase, noise figures, electrical strip isolation, full depletion voltage evolution, and charge collection efficiency.

Development of radiation hard semiconductor sensors for charged particle tracking at very high luminosities

Abstract: The RD50 collaboration (sponsored by the European Organization for Nuclear Research CERN) has been exploring the development of radiation hard semiconductor devices for very high-luminosity colliders since 2002. The target fluence to qualify detectors set by the anticipated dose for the innermost tracking layers of the future upgrade of the CERN large hadron collider (LHC) is 1016 1 MeV neutron equivalent (neq) cm−2. This is much larger than typical fluences in space, but is mainly limited to displacement and total dose damage, without the single-event effects typical for the space environment. RD50 investigates radiation hardening from many angles, including: Search for alternative semiconductor to replace silicon, improvement of the intrinsic tolerance of the substrate material (p- vs. n-type, initial doping concentration, oxygen concentration), optimization of the readout geometry (collection of holes or electrons, surface treatment), novel detector designs (3D, edge-less, interconnects).

Development of radiation-tolerant silicon microstrip sensor for the ATLAS inner tracker at the SLHC

Abstract: We have established the basic technology for a radiation-tolerant p-type silicon microstrip sensor for the ATLAS inner tracker at the SLHC, manufactured on 6-in. wafers without onset of microdischarge up to 1000 V. In comparison of wafer materials, little advantage was observed in the 6 in. p-type MCZ material to the p-FZ that was available in Japan. The evolution of the charge collection as a function of bias voltage showed that the proton-irradiated samples with apparent lower full depletion voltage collected less charge at saturation than the neutron irradiated samples.