Performance of a GridPix detector based on the Timepix3 chip

A GridPix readout for a TPC based on the Timepix3 chip is developed for future applications at a linear collider. The GridPix detector consists of a gaseous drift volume read out by a single Timepix3 chip with an integrated amplification grid. Its performance is studied in a test beam with 2.5 GeV electrons. The GridPix detector detects single ionization electrons with high efficiency. The Timepix3 chip allowed for high sample rates and time walk corrections. Diffusion is found to be the dominating error on the track position measurement both in the pixel plane and in the drift direction, and systematic distortions in the pixel plane are below 10 $\mu$m. Using a truncated sum, an energy loss (dE/dx) resolution of 4.1% is found for an effective track length of 1 m.Comment: To be published in Nuclear Instruments and Methods in Physics Research Section

A UV Sensitive Integrated Micromegas with Timepix Readout

This article presents a detector system consisting of three components, a CMOS imaging array, a gaseous-detector structure with a Micromegas layout and a UV-photon sensitive CsI reflective photocathode. All three elements have been monolithically integrated using simple post-processing steps. The Micromegas structure and the CMOS imaging chip are not impacted by the CsI deposition. The detector operated reliably in He/isobutane mixtures and attained charge gains with single photons up to a level of 6 \cdot 10^4. The Timepix CMOS array permitted high resolution imaging of single UV-photons. The system has an MTF50 of 0.4 lp/pixel which corresponds to app. 7 lp/mm.Comment: 4 pages with 8 figures. Submitted to Nucl. Instr. and Meth. A (Elsevier) for proceedings of VCI 2010

The use of project technologies in the training of students

The new millennium is characterized by an unprecedented breakthrough in knowledge and information and communication technologies. The challenges of the XXI century require modernized paradigms of interaction in all spheres of life, including the educational one. To date, one of the most promising teaching methods is project technology. It forms the conditions for creative self-realization of students, increases their motivation to learn, and promotes the development of intellectual abilities that contribute to the acquisition of students’ own experience in solving problems of future independent life, which they project in their studies. The professional training of the student is enhanced through the use of project technologies, so students have to develop technical skills to be productive members of society. The research aims – to establish a pattern of promoting the implementation of project technologies in educational institutions by surveying the Internet. Another aim is to establish the ability of educational institutions to provide quality competent training to HEI students. Research methods: comparative analysis; systematization; generalization, and survey. Results. It has been established that as a result of the survey of students, project technologies have a positive impact on the provision of competent training of students (95.5%). A smaller number of students (3.3%) were not confident in the quality of competent training of students by modern project technologies. Whereas the rest of the students have noted that modern project technologies for competent training of students contain certain shortcomings (1.2%). As a result of the study, it was found that students positively evaluate (with scores above 5.0) project technologies as practical, understandable, motivating, etc. As a result of the study, it has been found that the implementation of project technologies for the professional training of university students is a complex process due to the large number of variables that should be taken into account both in the course and at the individual level. Moreover, it has been established that the implementation of the proposed model of integrating project technologies into the process of forming competitive advantages for university students benefits both students and educators by establishing reliable communication between them and stimulating the provision of qualified training

Properties of CdTe thin films prepared by hot wall epitaxy

CdTe thin films were grown on different substrates: BaF₂ (111), polished Si (100), SiO₂, bulk CdTe (110) and HgxCd₁₋xTe layers by hot wall epitaxy (HWE). Chosen temperature parame-ters and technological process of thin film fabrication provided the growth rate of about 0.03 mm/min. The current-voltage characteristics and transmission spectra were measured. X-ray diffrac-tion data (XRD) measurements were carried out as well

An integrated Micromegas UV-photon detector

Preliminary results of a photon detector combining a Micromegas like multiplier coated with a UV-sensitive CsI photocathode are described. The multiplier is made in a CMOS compatible InGrid technology, which allows to post-process it directly on the surface of an imaging IC. This method is aimed at building light-sensitive imaging detectors where all elements are monolithically integrated. We show that the CsI photocathode deposited in the InGrid mesh does not alter the device performance. Maximum gains of ~6000 were reached in a single-grid element operated in Ar/CH4, with a 2% Ion Back Flow fraction returning to the photocathode.Comment: 5 pages with 6 figures. This paper is submitted to Nuclear Instruments and Methods A (Elsevier) for the proceedings of IWORID 2009

The performance of GridPix detectors

A GridPix detector is a gaseous detector capable of detecting individual single primary electrons from ionizing particles. Such a detector consists of a pixel chip as active anode covered with a thin layer of silicon rich silicon nitride (SiRN) for protection against discharges, an integrated amplification grid (InGrid), applied on top of the chip by wafer post processing techniques, and a cathode plane. The drift region is between the grid and cathode while the gas gain occurs between the chip and the grid. The discharge quenching properties of the SiRN layer have been determined as well as the relation on grid capacitance, grid voltage and gas mixture. Part of the detectors in this report were of the type Gossip, a GridPix detector with a drift gap of ∼1 mm. Using such thin drift layer, one may consider this detector as a replacement for a silicon pixel detector. The performance of three Gossip detectors has been investigated by measurements in a test beam at CERN

Infrastructure for Detector Research and Development towards the International Linear Collider

The EUDET-project was launched to create an infrastructure for developing and testing new and advanced detector technologies to be used at a future linear collider. The aim was to make possible experimentation and analysis of data for institutes, which otherwise could not be realized due to lack of resources. The infrastructure comprised an analysis and software network, and instrumentation infrastructures for tracking detectors as well as for calorimetry.Comment: 54 pages, 48 picture

Reliable cool-down of GridPix detectors for cryogenic applications

In this paper we present thermal cycling experiments of GridPix radiation imaging detectors, in view of a potential application in a cryogenic experiment. The robustness of the GridPix detector is studied for various grid designs, as well as various mechanical and thermal surroundings. The grid design variations had insignificant effect on the grid strength. A low cool-down rate as well as good thermal contact are crucial for the durability of the grid. Further, additional strengthening at the grid edges proved necessary to maintain the integrity of the structure during thermal cycling, which was done using globtop adhesive. The combination of these measures led to 100% survival rate after thermal cycling down to −130 °C