| 1. |
- Abdesselam, A., et al.
(författare)
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Engineering for the ATLAS SemiConductor Tracker (SCT) end-cap
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221 .- 1748-0221. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- The ATLAS SemiConductor Tracker (SCT) is a silicon-strip tracking detector which forms part of the ATLAS inner detector. The SCT is designed to track charged particles produced in proton-proton collisions at the Large Hadron Collider (LHC) at CERN at an energy of 14 TeV. The tracker is made up of a central barrel and two identical end-caps. The barrel contains 2112 silicon modules, while each end-cap contains 988 modules. The overall tracking performance depends not only on the intrinsic measurement precision of the modules but also on the characteristics of the whole assembly, in particular, the stability and the total material budget. This paper describes the engineering design and construction of the SCT end-caps, which are required to support mechanically the silicon modules, supply services to them and provide a suitable environment within the inner detector. Critical engineering choices are highlighted and innovative solutions are presented - these will be of interest to other builders of large-scale tracking detectors. The SCT end-caps will be fully connected at the start of 2008. Further commissioning will continue, to be ready for proton-proton collision data in 2008.
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| 2. |
- Abdesselam, A., et al.
(författare)
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The ATLAS semiconductor tracker end-cap module
- 2007
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 575:3, s. 353-389
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Tidskriftsartikel (refereegranskat)abstract
- The challenges for the tracking detector systems at the LHC are unprecedented in terms of the number of channels, the required read-out speed and the expected radiation levels. The ATLAS Semiconductor Tracker. (SCT) end-caps have a total of about 3 million electronics channels each reading out every 25 ns into its own on-chip 3.3 mu s buffer. The highest anticipated dose after 10 years operation is 1.4x10(14) cm(-2) in units of 1 MeV neutron equivalent (assuming the damage factors scale with the non-ionising energy loss). The forward tracker has 1976 double-sided modules, mostly of area similar to 70 cm(2), each having 2 x 768 strips read out by six ASICs per side. The requirement to achieve an average perpendicular radiation length of 1.5% X-0, while coping with up to 7 W dissipation per module (after irradiation), leads to stringent constraints on the thermal design. The additional requirement of 1500e(-) equivalent noise charge (ENC) rising to only 1800e(-) ENC after irradiation, provides stringent design constraints on both the high-density Cu/Polyimide flex read-out circuit and the ABCD3TA read-out ASICs. Finally, the accuracy of module assembly must not compromise the 16 mu m (r phi) resolution perpendicular to the strip directions or 580 mu m radial resolution coming from the 40 mrad front-back stereo angle. A total of 2210 modules were built to the tight tolerances and specifications required for the SCT. This was 234 more than the 1976 required and represents a yield of 93%. The component flow was at times tight, but the module production rate of 40-50 per week was maintained despite this. The distributed production was not found to be a major logistical problem and it allowed additional flexibility to take advantage of where the effort was available, including any spare capacity, for building the end-cap modules. The collaboration that produced the ATLAS SCT end-cap modules kept in close contact at all times so that the effects of shortages or stoppages at different sites could be rapidly resolved.
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| 3. |
- Copier, J, et al.
(författare)
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Improving the efficacy of cancer immunotherapy
- 2009
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Ingår i: EUROPEAN JOURNAL OF CANCER. - : Elsevier BV. - 0959-8049 .- 1879-0852. ; 45:8, s. 1424-1431
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Tidskriftsartikel (refereegranskat)abstract
- A series of cancer vaccines have been evaluated in clinical trials with encouraging results, but the demonstration of clinical benefit in confirmatory studies has so far proven to be difficult. The development of cancer vaccines is hampered by a range of issues particular to this field of research. On 12th March 2008, the Biotherapy Development Association convened a workshop to discuss issues faced by scientists and clinicians involved in the development of cancer vaccines. This paper is a review of the field, based on discussions held at the BDA workshop, and describes biological barriers encountered in generating effective immune responses to tumours, methodological obstacles encountered in the improvement of immunological monitoring which aims to improve inter-laboratory and inter-trial comparisons, challenges in clinical trial design and problems posed by the lack of specific regulation for cancer vaccines and the impact on their development. Ultimately, a number of general solutions are posed: (1) better patient selection, (2) use of multi-modal treatments that affect several aspects of the immune system at once, (3) a requirement for the development of good biomarkers to stratify patients for selection prior to trial and as surrogates for clinical response and (4) harmonisation of SOPs for immunological monitoring of clinical trials.
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| 4. |
- Hareter, M., et al.
(författare)
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MOST discovers a multimode delta Scuti star in a triple system : HD 61199
- 2008
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 492:1, s. 185-195
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Tidskriftsartikel (refereegranskat)abstract
- Context. A field star, HD61199 (V approximate to 8), simultaneously observed with Procyon by the MOST (Microvariability & Oscillations of STars) satellite in continuous runs of 34, 17, and 34 days in 2004, 2005, and 2007, was found to pulsate in 11 frequencies in the delta Scuti range with amplitudes from 1.7 down to 0.09 mmag. The photometry also showed variations with a period of about four days. To investigate the nature of the longer period, 45 days of time-resolved spectroscopy was obtained at the Thuringer Landessternwarte Tautenburg in 2004. The radial velocity measurements indicate that HD61199 is a triple system. Aims. A delta Scuti pulsator with a rich eigenspectrum in a multiple system is promising for asteroseismology. Our objectives were to identify which of the stars in the system is the delta Scuti variable and to obtain the orbital elements of the system and the fundamental parameters of the individual components, which are constrained by the pulsation frequencies of the delta Scuti star.Methods. Classical Fourier techniques and least-squares multi-sinusoidal fits were applied to the MOST photometry to identify the pulsation frequencies. The groundbased spectroscopy was analysed with least-squares-deconvolution (LSD) techniques, and the orbital elements derived with the KOREL and ORBITX routines. Asteroseismic models were also generated. Results. The photometric and spectroscopic data are compatible with a triple system consisting of a close binary with an orbital period of 3.57 days and a d Scuti companion (HD61199 A) as the most luminous component. The d Scuti star is a rapid rotator with about v sin i = 130 km s(-1) and an upper mass limit of about 2.1 M-circle dot. For the close binary components, we find they are of nearly equal mass, with lower mass limits of about 0.7 M-circle dot. Comparisons to synthetic spectra indicate these stars have a late-F spectral type. The observed oscillation frequencies are compared to pulsation models to further constrain the evolutionary state and mass of HD61199 A. The orbit frequency of the close binary corresponds to the difference of the two d Scuti frequencies with the highest amplitudes a coincidence that is remarkable, but not explained.
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