Cluster Imaging with a Direct Detection CMOS Pixel Sensor in Transmission Electron Microscopy

A cluster imaging technique for Transmission Electron Microscopy with a direct detection CMOS pixel sensor is presented. Charge centre-of-gravity reconstruction for individual electron clusters improves the spatial resolution and thus the point spread function. Data collected with a CMOS sensor with 9.5 micron pixels show an improvement of a factor of two in point spread function to 2.7 micron at 300 keV and of a factor of three in the image contrast, compared to traditional bright field illumination.Comment: 6 pages, 3 figures, submitted to Nucl. Instr. Meth.

Development of CMOS monolithic pixel sensors with in-pixel correlated double sampling and fast readout for the ILC

This paper presents the design and results of detailed tests of a CMOS active pixel chip for charged particle detection with in-pixel charge storage for correlated double sampling and readout in rolling shutter mode at frequencies up to 25 MHz. This detector is developed in the framework of R&D for the Vertex Tracker for the International Linear Collider.Comment: 3 pages, 4 figures, to appear on the Conference Record of the 2007 IEEE Nuclear Science Symposium, Honolulu, HI, October 200

Efficient numerical method to handle boundary conditions in 2D elastic media

A numerical method is developed to efficiently calculate the stress (and displacement) field in finite 2D rectangular media. The solution is expanded on a function basis with elements that satisfy the Navier-Cauchy equation. The obtained solution approximates the boundary conditions with their finite Fourier series. The method is capable to handle Dirichlet, Neumann and mixed boundary value problems as well and it was found to converge exponentially fast to the analytical solution with respect to the size of the basis. Possible application in discrete dislocation dynamics simulations is discussed and compared to the widely used finite element methods: it was found that the new method is superior in terms of computational complexity.Comment: 21 pages, 10 figure

Characterisation of a Thin Fully Depleted SOI Pixel Sensor with High Momentum Charged Particles

This paper presents the results of the characterisation of a thin, fully depleted pixel sensor manufactured in SOI technology on high-resistivity substrate with high momentum charged particles. The sensor is thinned to 70 $\mu$m and a thin phosphor layer contact is implanted on the back-plane. Its response is compared to that of thick sensors of same design in terms of signal and noise, detection efficiency and single point resolution based on data collected with 300 GeV pions at the CERN SPS. We observe that the charge collected and the signal-to-noise ratio scale according to the estimated thickness of the sensitive volume and the efficiency and single point resolution of the thinned chip are comparable to those measured for the thick sensors.Comment: 8 pages, 3 figures, submitted to Nucl. Instr. and Meth., section

Characterisation of a Thin Fully-Depleted SOI Pixel Sensor with Soft X-ray Radiation

This paper presents the results of the characterisation of a back-illuminated pixel sensor manufactured in Silicon-On-Insulator technology on a high-resistivity substrate with soft X-rays. The sensor is thinned and a thin Phosphor layer contact is implanted on the back-plane. The response to X-rays from 2.12 up to 8.6 keV is evaluated with fluorescence radiation at the LBNL Advanced Light Source.Comment: 9 pages, 5 figures, submitted to Nuclear Instruments and Methods