17032836
Radiation Hardness of CCD Vertex Detectors for the ILC
Results of detailed simulations of the charge transfer inefficiency of a prototype CCD chip are reported. The effect of radiation damage in a particle detector operating at a future accelerator is studied by examining two electron trap levels, 0.17 eV and 0.44 eV below the bottom of the conduction band. Good agreement is found between simulations using the ISE-TCAD DESSIS program and an analytical model for the 0.17 eV level. Optimum operation is predicted to be at about 250 K where the effects of the traps is minimal which is approximately independent of readout frequency. This work has been carried out within the Linear Collider Flavour Identification (LCFI) collaboration in the context of the International Linear Collider (ILC) project.
126252051
Understanding and calibrating the DS-ECal for T2K's ND280
121516515
The T2K experiment and downstream electromagnetic calorimeter
T2K (Tokai to Kamioka) is a 295km long-baseline experiment in Japan, which is due to start taking commissioning data late in 2009. It is designed to measure muon-neutrino oscillations to other flavours. This will enable the measurement of some of the components of the MNSP mixing matrix. One of the UK's main contributions is the construction of an Electromagnetic Calorimeter (ECal) for the near detector, ND280, situated 280m downstream from the neutrino production target. This poster focuses on the Downstream ECal. Construction of this key module is due to begin in October 2007. It is then to be packaged and shipped to CERN in Spring 2009 for calibration tests and it is the aim that it will be installed in Tokai later in 2009. Lancaster University is responsible for the construction of the DS-ECal.
25386498
Simulations of the Temperature Dependence of the Charge Transfer Inefficiency in a High-Speed CCD
Results of detailed simulations of the charge transfer inefficiency of a prototype serial readout CCD chip are reported. The effect of radiation damage on the chip operating in a particle detector at high frequency at a future accelerator is studied, specifically the creation of two electron trap levels, 0.17 eV and 0.44 eV below the bottom of the conduction band. Good agreement is found between simulations using the ISE-TCAD DESSIS program and an analytical model for the former level but not for the latter. Optimum operation is predicted to be at about 250 K where the effects of the traps is minimal; this being approximately independent of readout frequency in the range 7-50 MHz. This work has been carried out within the Linear Collider Flavour Identification (LCFI) collaboration in the context of the International Linear Collider (ILC) project.
17593732
Standard Model Higgs Search in the Four Jet Channel at LEP
The Standard Model Higgs boson was searched for at LEP, by the four collaborations in the year 2000, at centre-of-mass energies from 200-209GeV. An excess of events, potentially compatible with the production of a Higgs boson of mass ~115GeV was observed, largely in the four-jet channel. The search in this channel is discussed in this letter.
117811148
Recent results from UK dark matter experiments in the Boulby mine.
55934185
Test results from a prototype lead tungstate crystal calorimeter with vacuum phototriode readout for the CMS experiment
Abstract Tests of a prototype for the electromagnetic calorimeter (ECAL) of the compact muon solenoid experiment (CMS) at the large hadron collider are described. The basic unit for the endcap ECAL in CMS is a “supercrystal” of 25 lead tungstate crystals. Results are presented from tests of the first full-sized supercrystal in electron beams and in a 3 T magnetic field. The supercrystal was exposed to electron beams with energies from 25 to 180 GeV. An energy resolution ( σ E / E ) of (0.48±0.01)% was measured at 180 GeV.
123388474
Statistical techniques developed by the UKDMC to calculate the 90% c.l. upper limit of the WIMP component of the Galactic dark matter
This paper outlines statistical techniques developed by the UK Dark Matter Collaboration to convert the resultant energy spectra from NaI crystal scintillation detectors to a 90% confidence level upper limit to the rate of the hypothetical weakly interacting massive dark matter particle, the WIMP. In simple counting systems a chi-square surface minimisation technique is used, the 90% c.l. arising from Monte Carlo simulations. In detectors that exhibit electron from nuclear recoil discrimination a comparison between the observed spectrum and that from gamma and neutron calibrations is performed with chi-square, Kolmogorov-Smirnov and Cramer-von-Mises tests to give the most likely signal, with Monte Carlo simulations again yielding the 90% c.l.