Are Large-Aperture NbTi Magnets Compatible with 1e35?

To protect magnets in the insertion region, we have some degrees of freedom to use for optimal performance. Aperture, distance from the IP, the length of the magnets and the design of absorption systems are important parameters for the optimization. We look exclusively here at the effects of the collision debris, which give the major contribution to the heat deposition in the insertion magnets. To answer the challenging question in the title of this contribution, the approach was to use the baseline upgrade scenario for phase 1 and simply imagine higher particle fluxes from the higher luminosity (no change in optics). From this, a simple approach of magnet shielding using a liner in the cold bore tube gave us the answer: NbTi technology may be compatible with a luminosity of 1035. This gives also the interesting possibility to extract heat from this liner at a higher cryogenic temperature. However the final demonstration needs a detailed model. We have also made some parameter variations (crossing angle, TAS aperture) and checked the Q0 upgrade scenario concerning deposited heat. The effect of a D0 magnet on heat deposition in the IR has also been evaluated

Automatic beam steering in the CERN PS complex

The recombination, transfer and injection of the four beams from the PS Booster to the PS Main Ring, have a high level of intri-cacy and are a subject of permanent concern for the operation of the PS Injector Complex. These tasks were thus selected as a test bench for the implementation of a prototype of an auto-matic beam steering system. The core of the system is based on a generic trajectory optimizer, robust enough to cope with imper-fect observations. The algorithmic engine is connected to pick-up monitors and corrector magnets and its decision can be val-idated by the operator through a graphics user interface. Auto-matic beam steering can only be ef®cient if the beam optics is fully con®rmed by experimental observations, a conditionwhich forces the systematic elimination of errors both in hardware and software. I

Characterization of infectious and defective cloned avian hepadnavirus genomes

The infectivity in vivo, replication competence in vitro, and expression of viral genes of several molecularly cloned duck hepatitis B virus (DHBV) genomes were investigated. In addition, replication competence, core protein expression, and secretion of viral proteins were investigated for a grey heron hepatitis B virus genome. Except two, all DHBV isolates tested induced a systemic infection in Pekin ducks when injected as cloned viral DNA into the liver. After transfection of chicken hepatoma cells, both defective DHBV genomes expressed intracellular nucleocapsid and pre-S envelope proteins and secreted DHBs/pre-S particles into the medium. One of the defective DHBV genomes and HHBV produced within the cells replicative intermediates encapsidated in core particles and secreted virions, whereas the other defective DHBV genome did not and was unable to efficiently encapsidate the RNA pregenome. Comparative sequence analysis was performed to identify potential amino acid changes in viral proteins of both defective DHBV genomes. The data obtained demonstrate that most cloned avian hepadnaviruses are infectious or replication competent and suggest defects in envelope, polymerase or encapsidation function, respectively, in two cloned DHBV genomes

Parametric Study of Heat Deposition from Collision Debris into the Insertion Superconducting Magnets for the LHC Luminosity Upgrade

With a new geometry in a higher luminosity environment, the power deposition in the superconducting magnets becomes a critical aspect to analyze and to integrate in the insertion design. In this paper, we quantify the power deposited in magnets insertion at variable positions from the interaction point (IP). A fine characterization of the debris due to the proton-proton collisions at 7 TeV, shows that the energetic particles in the very forward direction give rise to non intuitive dependences of the impacting energy on the magnet front face and inner surface. The power deposition does not vary significantly with the distance to the interaction point, because of counterbalancing effects of different contributions to power deposition. We have found out that peak power density in the magnet insertion does not vary significantly with or without the Target Absorber Secondaries (TAS) protection

Long-Term Followup Comparing Two Treatment Dosing Strategies of 125

Objective. To investigate the efficacy of two different dosing strategies of radioactive iodine-125 (125I) in the management of small- and medium-sized posterior uveal melanoma. Patients and Methods. The medical records of consecutive patients with choroidal melanomas between 1.5 and 5.0 mm in apical height treated initially with 125I plaque radiotherapy were reviewed. Patients were treated with one of the following two treatment dosing strategies: (1) 85 Gy to the apical height of the tumor (group 1) or (2) 85 Gy to a prescription point of 5.0 mm (group 2). Results. Of 95 patients, 55 patients were treated to the apical height of the tumor, and 40 were treated to a prescription point of 5.0 mm. Comparative analysis of the incidence rates of specific complications between the two groups demonstrates that group 2 had a significantly higher incidence of radiation retinopathy, radiation optic neuropathy, and/or visually significant cataract formation than group 1 (). Conclusion. Treatment of choroidal melanomas less than 5 mm in apical height with 125I brachytherapy to the true apical height is equally effective when compared to treatment with 85 Gy to 5.0 mm. Treatment to the apical height of the tumor may result in lower incidence of radiation-related complications