Monitoring international migration flows in Europe. Towards a statistical data base combining data from different sources

The paper reviews techniques developed in demography, geography and statistics that are useful for bridging the gap between available data on international migration flows and the information required for policy making and research. The basic idea of the paper is as follows: to establish a coherent and consistent data base that contains sufficiently detailed, up-to-date and accurate information, data from several sources should be combined. That raises issues of definition and measurement, and of how to combine data from different origins properly. The issues may be tackled more easily if the statistics that are being compiled are viewed as different outcomes or manifestations of underlying stochastic processes governing migration. The link between the processes and their outcomes is described by models, the parameters of which must be estimated from the available data. That may be done within the context of socio-demographic accounting. The paper discusses the experience of the U.S. Bureau of the Census in combining migration data from several sources. It also summarizes the many efforts in Europe to establish a coherent and consistent data base on international migration. The paper was written at IIASA. It is part of the Migration Estimation Study, which is a collaborative IIASA-University of Groningen project, funded by the Netherlands Organization for Scientific Research (NWO). The project aims at developing techniques to obtain improved estimates of international migration flows by country of origin and country of destination

Proceedings of the Asia Pacific Solar Research Conference 2018

How does one best ensure success in photovoltaic (PV) energy access initiatives? By documenting the design process for a technology-based intervention, developed through a UNSW Sydney and University of the South Pacific (USP) collaboration with the Viwa Island community in Fiji, the study presented in this paper investigates, tests and assesses best practices in implementing PV solutions for the purpose of sustainable development. The work serves as a foundation for project continuation, providing recommendations for implementation and arguing that a sociocultural focus must be prioritised when technologies operate within complex systems.Pacific Island countries are experiencing compounding pressures as a result of climate change, urbanisation and population growth. In the broader context of the Sustainable Development Goals, this necessitates the urgent deployment of innovative solutions to build on livelihood assets and enhance the resilience of base of pyramid populations. As the nascent o -grid solar refrigeration sector develops, the possibility of clean and affordable temperature controlled supply chains - cold chains, could play a vital role in empowering remote island communities that are dependent on agriculture or fishing for livelihoods.Through literature review, participatory fieldwork, technology assessment and desk-based ideation, recommendations have been drawn to facilitate the implementation of energy services enabling cold storage within the Viwa community. Based on a systems thinking approach, this study also highlights how a collaboration between UNSW and USP could assist in deployment of new technologies; delivering direct benefits to remote island fisherfolk, whilst providing learning opportunities for the research community as a whole. Importantly, success critically depends on community consensus and specific measures including a comprehensive and ongoing monitoring program

Delivery of Energy Services in Unfamiliar Contexts: Learnings from Fiji

How does one best ensure success in photovoltaic (PV) energy access initiatives? By documenting the design process for a technology-based intervention, developed through a UNSW Sydney and University of the South Pacific (USP) collaboration with the Viwa Island community in Fiji, the study presented in this paper investigates, tests and assesses best practices in implementing PV solutions for the purpose of sustainable development. The work serves as a foundation for project continuation, providing recommendations for implementation and arguing that a sociocultural focus must be prioritised when technologies operate within complex systems. Pacific Island countries are experiencing compounding pressures as a result of climate change, urbanisation and population growth. In the broader context of the Sustainable Development Goals, this necessitates the urgent deployment of innovative solutions to build on livelihood assets and enhance the resilience of base of pyramid populations. As the nascent off-grid solar refrigeration sector develops, the possibility of clean and affordable temperaturecontrolled supply chains - cold chains, could play a vital role in empowering remote island communities that are dependent on agriculture or fishing for livelihoods. Through literature review, participatory fieldwork, technology assessment and desk-based ideation, recommendations have been drawn to facilitate the implementation of energy services enabling cold storage within the Viwa community. Based on a systems thinking approach, this study also highlights how a collaboration between UNSW and USP could assist in deployment of new technologies; delivering direct benefits to remote island fisherfolk, whilst providing learning opportunities for the research community as a whole. Importantly, success critically depends on community consensus and specific measures including a comprehensive and ongoing monitoring program

High power RF test of an 805 MHz RF cavity for a muon cooling channel

We present recent high power RF test results on an 805 MHz cavity for a muon cooling experiment at Lab G in Fermilab. In order to achieve high accelerating gradient for large transverse emittance muon beams, the cavity design has adopted a pillbox like shape with 16 cm diameter beam iris covered by thin Be windows, which are demountable to allow for RF tests of different windows. The cavity body is made from copper with stiff stainless steel rings brazed to the cavity body for window attachments. View ports and RF probes are available for visual inspections of the surface of windows and cavity and measurement of the field gradient. Maximum of three thermo-couples can be attached to the windows for monitoring the temperature gradient on the windows caused by RF heating. The cavity was measured to have Q{sub 0} of about 15,000 with copper windows and coupling constant of 1.3 before final assembling. A 12 MW peak power klystron is available at Lab G in Fermilab for the high power test. The cavity and coupler designs were performed using the MAFIA code in the frequency and the time domain. Numerical simulation results and cold test measurements on the cavity and coupler will be presented for comparisons

High power RF test of an 805 MHz RF cavity for a muon cooling channel

We present recent high power RF test results on an 805 MHz cavity for a muon cooling experiment at Lab G in Fermilab. In order to achieve high accelerating gradient for large transverse emittance muon beams, the cavity design has adopted a pillbox like shape with 16 cm diameter beam iris covered by thin Be windows, which are demountable to allow for RF tests of different windows. The cavity body is made from copper with stiff stainless steel rings brazed to the cavity body for window attachments. View ports and RF probes are available for visual inspections of the surface of windows and cavity and measurement of the field gradient. Maximum of three thermo-couples can be attached to the windows for monitoring the temperature gradient on the windows caused by RF heating. The cavity was measured to have Q{sub 0} of about 15,000 with copper windows and coupling constant of 1.3 before final assembling. A 12 MW peak power klystron is available at Lab G in Fermilab for the high power test. The cavity and coupler designs were performed using the MAFIA code in the frequency and the time domain. Numerical simulation results and cold test measurements on the cavity and coupler will be presented for comparisons

RF tests of an 805 MHz pillbox cavity at Lab G of Fermilab

We report recent high power RF tests on an 805 MHz RF pillbox cavity with demountable windows for beam apertures at Lab G of Fermilab, a dedicated facility for testing of MUCOOL (muon cooling) components. The cavity is installed inside a superconducting solenoidal magnet. A 12 MW peak RF power klystron is used for the tests. The cavity has been processed both with and without magnetic field. Without magnetic field, a gradient of 34 MV/m was reached rather quickly with very low sparking rate. In a 2.5 T solenoidal field, a 16 MV/m gradient was achieved, and it had to take many weeks of conditioning. Strong multipacting effects associated with high radiation levels were measured during the processing with the magnetic field. More recently Be windows with TiN-coated surface have been installed and tested at conditions of with and without the external magnetic field. A conservative 16 MV/m gradient without magnetic field was reached quickly as planned. Less multipacting was observed during the conditioning, it indicated that the TiN-coated surface on the windows had indeed helped to reduce the secondary electron emissions significantly. A modest gradient of 16.5 MV/m was finally achieved with magnet on in solenoidal mode and the field up to 4 T. Preliminary inspection on Be windows surface found no damage at all, in comparison with Cu windows where substantial surface damage was found. Preliminary understanding of conditioning cavity in a strong magnetic field has been developed. More through window and cavity surface inspection is under way

805 MHz and 201 MHz RF cavity development for MUCOOL

A muon cooling channel calls for very high accelerating gradient RF structures to restore the energy lost by muons in the absorbers. The RF structures have to be operated in a strong magnetic field and thus the use of superconducting RF cavities is excluded. To achieve a high shunt impedance while maintaining a large enough aperture to accommodate a large transverse emittance muon beam, the cavity design adopted is a pillbox-like geometry with thin Be foils to terminate the electromagnetic field at the cavity iris. The possibility of using grids of thin-walled metallic tubes for the termination is also being explored. Many of the RF-related issues for muon cooling channels are being studied both theoretically and experimentally using an 805 MHz cavity that has a pillbox-like geometry with thin Be windows to terminate the cavity aperture. The design and performance of this cavity are reported here. High-power RF tests of the 805 MHz cavity are in progress at Lab G in Fermilab. The cavity has exceeded its design gradient of 30 MV/m, reaching 34 MV/m without external magnetic field. No surface damage was observed at this gradient. The cavity is currently under conditioning at Lab G with an external magnetic field of 2.5 T. We also present here a 201 MHz cavity design for muoncooling channels. The proposed cavity design is also suitable for use in a proof-of-principle Muon Ionization Cooling Experiment (MICE)