Beam dynamics in NF-FFAG EMMA with dynamical maps

Copyright @ 2010 by IPAC'10/ACFAThe Non-Scaling Fixed Field Alternating Gradient accelerator EMMA has a compact linear lattice, in which the effects of magnet fringe fields need to be modelled carefully. A numerical magnetic field map can be generated frommagnetmeasurements ormagnet design software. We have developed a technique that produces from the numerical field map, a dynamical map for a particle travelling in a full EMMA cell, for a given reference energy, without acceleration. Since the beam dynamics change with energy, a set of maps have been produced with various reference energies between 10MeV and 20MeV. For each reference energy, the simulated tune and time of flight have been compared with results in Zgoubi - tracking directly through numerical field map. The range of validity of a single map has been investigated by tracking particles with large energy deviation: the results can be used to implement a model of acceleration based on dynamical mapsThis work was supported by the Engineering and Physical Sciences Research Council (EPSRC), UK

Electromagnetic Field Plot of an Inductive Window by the Moment Method

A moment method is used to plot the electromagnetic field of an inductive window in a TE10 -mode rectangular waveguide. Green\u27s dyadic functions are derived based on Tai\u27s approach, which is a modified form of Hansen\u27s vector wave functions. Based on the computed electric fields, the S matrix and the equivalent aperture reactance of the waveguide window are calculated. This calculation agrees with the previously published closed-form results of Marcuvitz

Particle Tracking Studies Using Dynamical Map Created from Finite Element Solution of the EMMA Cell

The un­con­ven­tion­al size and the pos­si­bil­i­ty of trans­verse dis­place­ment of the mag­nets in the EMMA non-scal­ing FFAG mo­ti­vates a care­ful study of par­ti­cle be­hav­ior with­in the EMMA ring. The mag­net­ic field map of the dou­blet cell is com­put­ed using a Fi­nite El­e­ment Method solver; par­ti­cle mo­tion through the field can then be found by nu­mer­i­cal in­te­gra­tion, using (for ex­am­ple) OPERA, or ZGOUBI. How­ev­er, by ob­tain­ing an an­a­lyt­i­cal de­scrip­tion of the mag­net­ic field (by fit­ting a Fouri­er-Bessel se­ries to the nu­mer­i­cal data) and using a dif­fer­en­tial al­ge­bra code, such as COSY, to in­te­grate the equa­tions of mo­tion, it is pos­si­ble to pro­duce a dy­nam­i­cal map in Tay­lor form. This has the ad­van­tage that, after once com­put­ing the dy­nam­i­cal map, mul­ti-turn track­ing is far more ef­fi­cient than re­peat­ed­ly per­form­ing nu­mer­i­cal in­te­gra­tions. Also, the dy­nam­i­cal map is small­er (in terms of com­put­er mem­o­ry) than the full mag­net­ic field map; this al­lows dif­fer­ent con­fig­u­ra­tions of the lat­tice, in terms of mag­net po­si­tions, to be rep­re­sent­ed very eas­i­ly using a set of dy­nam­i­cal maps, with in­ter­po­la­tion be­tween the co­ef­fi­cients in dif­fer­ent maps*

Distance, multimedia and web delivery in surveying and GIS courses at the University Of Southern Queensland

[Abstract]: The University of Southern Queensland has been involved with the distance education of surveying courses for over 25 years. In recent times, staff of the Surveying and Land Information Discipline, and the University as a whole, have embarked on multimedia enhancement and web delivery of curricula. This paper examines some of the initiatives undertaken to enhance the delivery of educational materials and discusses some of the issues involved in the effective delivery of distance education materials. The significant experience in the delivery of traditional educational materials has proven to be an advantage in the repackaging and enhancement of teaching materials. Delivery of education to off-campus students requires a significant support infrastructure which is often not recognised by new entrants into the flexible delivery arena. Traditional support mechanisms such as phone, fax and standard media (eg. videos, audio tapes etc) are being replaced by email, ‘electronic’ discussion groups, CDs and internet resources. These enhancements, when developed professionally, require a significant commitment of resources and expertise and often require a team approach to their design and development. Access by off-campus students to internet services and affordable software packages also require careful consideration in the design and offering of distance education materials

High power photon collimators for the ILC.

An undulator-based source has been chosen as a part of the baseline configuration for the International Linear Collider (ILC) to generate an intense beam of polarised positrons. A photon collimator placed between the undulator and the target can be used to adjust the size, intensity and polarisation of the photon beam impacting the target, and can also protect the target station and limit the activation of downstream components. In this paper, we calculate quantities such as the energy deposition, temperature change, activation and dose rate for different designs of the photon collimator, and consider the advantages and disadvantages for each case

Progenitor cells are responsible for formation of human prostate epithelium primary cultures

To analyze cell viability and morphology of primary cell cultures from CD133 immunolabeled and sorted cells from epithelium of patients suffering from benign prostate hyperplasia (BPH). Methods: Cells obtained from 5 patients were divided in two fractions. First fraction (CD133+/CD133–) was cultivated in DMEM with 10% FBS. Second fraction was mixed with CD133 microbeads and immunomagnetically divided into CD133+ and CD133– fractions. These cells were cultivated and followed-up for 2 weeks. Cells were stained for Annexin V FITC/propidium iodide. Results: Seventy CD133+/CD133– cultures, thirty-one of CD133+ and thirty-one of CD133– cells were established. There were 5-fold and 3-fold increase of CD133+/CD133- and CD133+ cell number after 2 weeks, respectively. CD133+/CD133– and CD133+ monolayers displayed epithelial-like morphology and cytokeratine expression. CD133– cultures collapsed. Cell viability within CD133+ and CD133– populations was 90.1 ± 6.3% and 24.3 ± 6.2%, respectively. Apoptotic index was 9.0 ± 6.1% and 28.5 ± 23.8% within CD133+ and CD133– cultures, respectively. Conclusions: CD133 separated human primary epithelial cell cultures displayed differences in morphology, viability and apoptosis occurrence. Immunomagnetic sorting can be recommended in each in vitro experiments with primary cell cultures in order to provide more objective results.Цель: оценить жизнеспособность и морфологию клеток первичных клеточных культур, полученных из меченных по CD133 и полученных с помощью клеточной сортировки клеток эпителия пациентов с доброкачественной гиперплазией предстательной железы (BPH). Методы: клетки, полученные от 5 пациентов, были разделены на 2 фракции. Первую фракцию (CD133+/CD133–) выращивали в DMEM с 10% FBS али с CD133 магнитными гранулами и с помощью магнита разделили клетки на CD133+- и CD133–-фракции. Далее клетки культивировали в течении 2 нед. Клетки окрашивали аннексиномV FITC/пропидий йодидом. Результаты: получено 70 CD133+/CD133- -культур клеток, 31 CD133+ и 31 CD133–. Через 2 нед культивирования отмечали 5-кратное и 3-кратное увеличение количества CD133+/CD133– и CD133+ клеток соответственно. CD133+/CD133- -и CD133+-клетки росли в монослое и имели морфологию эпителиальных клеток, экспрессировали цитокератин. CD133–-клетки не выжили. Выживаемость клеток в популяциях CD133+ и CD133– была 90,1 ± 6,3% и 24,3 ± 6,2% соответственно. Показатель апоптического индекса для культур CD133+ и CD133– был 9,0 ± 6,1% и 28,5 ± 23,8% соответственно. Выводы: показаны различия в морфологии, выживаемости клеток и частоте апоптоза для эпителиальных клеток, разделенных в зависимости от экспрессии CD133. Сортировка клеток с помощью иммуномагнитного разделения рекомендована для каждого in vitro эксперимента с использованием первичных клеточных культур для получения более объективных результатов

A First Step Towards Automatically Building Network Representations

To fully harness Grids, users or middlewares must have some knowledge on the topology of the platform interconnection network. As such knowledge is usually not available, one must uses tools which automatically build a topological network model through some measurements. In this article, we define a methodology to assess the quality of these network model building tools, and we apply this methodology to representatives of the main classes of model builders and to two new algorithms. We show that none of the main existing techniques build models that enable to accurately predict the running time of simple application kernels for actual platforms. However some of the new algorithms we propose give excellent results in a wide range of situations

Closed orbit correction at synchrotrons for symmetric and near-symmetric lattices

This contribution compiles the benefits of lattice symmetry in the context of closed orbit correction. A symmetric arrangement of BPMs and correctors results in structured orbit response matrices of Circulant or block Circulant type. These forms of matrices provide favorable properties in terms of computational complexity, information compression and interpretation of mathematical vector spaces of BPMs and correctors. For broken symmetries, a nearest-Circulant approximation is introduced and the practical advantages of symmetry exploitation are demonstrated with the help of simulations and experiments in the context of FAIR synchrotrons