Strain induced crystallization and melting of natural rubber during dynamic cycles

Strain-induced crystallization (SIC) of natural rubber (NR) is studied during dynamic cycles at high frequencies (with equivalent strain rates ranging from 7.2 s-1 to 290 s-1). The testing parameters are varied: the frequency, the temperature and the stretching ratio domain. It is found that an increase of the frequency leads to an unexpected form of the CI–¿ curve, with a decrease of the crystallinity during both loading and unloading steps of the cycle. Nevertheless, the interpretation of the curves needs to take into account several phenomena such as (i) instability of the crystallites generated during the loading step, which increases with the frequency, (ii) the memory of the previous alignment of the chains, which depends on the minimum stretching ratio of the cycle ¿min and the frequency, and (iii) self-heating which makes the crystallite nucleation more difficult and their melting easier. Thus, when the stretching ratio domain is above the expected stretching ratio at complete melting ¿melt, the combination of these phenomena, at high frequencies, leads to unexpected results such as complete melting at ¿min, and hysteresis in the CI–¿ curves.Peer ReviewedPostprint (author's final draft

Towards a Muon Collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work.Comment: 118 pages, 103 figure

Towards a muon collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

Towards a muon collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

Erratum: Towards a muon collider

The original online version of this article was revised: The additional reference [139] has been added. Tao Han’s ORICD ID has been incorrectly assigned to Chengcheng Han and Chengcheng Han’s ORCID ID to Tao Han. Yang Ma’s ORCID ID has been incorrectly assigned to Lianliang Ma, and Lianliang Ma’s ORCID ID to Yang Ma. The original article has been corrected

Never Run Your ECR Ion Source with Argon in Afterglow for 6 Months!

The fixed target experiment NA61 in the North Area of the SPS at CERN studies phase transitions in strongly interacting matter using the primary beams available from the CERN accelerator complex (protons and lead ions). In order to explore a wider range of energies and densities a primary argon beam was requested for the physics run in 2015. The GTS-LHC ECR ion source was running for many months during 2013 and 2014 to study the source behaviour and to setup the accelerator chain with argon ions. This paper reports the long term effects of the argon operation on the GTS-LHC ion source and the Low Energy Beam Transport (LEBT). Heavy sputtering inside the source caused a degradation of the plasma chamber and metal coating of insulators inside the beam extraction system. Iron ions could be found in the extracted beam. Also the pumping performance of ion getter pumps in the LEBT degraded significantly. Additional preventive maintenance was necessary to be able to run for long periods without risking serious damage to the ion source.The fixed target experiment NA61/SHINE in the North Area of the SPS at CERN studies phase transitions in strongly interacting matter using the primary beams available from the CERN accelerator complex (protons and lead ions). In order to explore a wider range of energies and densities a primary argon beam was requested for the physics run in 2015. The GTS-LHC ECR ion source was running for many months during 2013 and 2014 to study the source behaviour and to set-up the accelerator chain with argon ions. This paper reports the long term effects of the argon op- eration on the GTS-LHC ion source and the Low Energy Beam Transport (LEBT). Heavy sputtering inside the source caused a degradation of the plasma chamber and metal coat- ing of insulators inside the beam extraction system. Iron ions could be found in the extracted beam. Also the pumping performance of ion getter pumps in the LEBT degraded sig- nificantly. Additional preventive maintenance was necessary to be able to run for long periods without risking serious damage to the ion source

Electrical Network Analysis for Vacuum Profile of MedAustron

MedAustron is a synchrotron based hadron therapy facility for cancer treatment currently under construction in Wiener Neustadt, Austria, 40 km south-west of Vienna. Ion beams of H+3 and C4+ are generated in gaseous plasma (H2 or CO2) in an Electron Cyclotron Resonance (ECR) ion source and extracted at a kinetic energy of 8 keV=u and transformed by the Low-Energy Beam Transfer line (LEBT). The beam of ions is then accelerated up to 400 keV/u in the Linear accelerator (LINAC) and transferred via the Medium Energy Beam Transfer line (MEBT) to the synchrotron. After extraction, the beam is transferred to the treatment rooms for cancer therapy use. The quality of the dose delivered to the patient for cancer treatment is ultimately determined by the performance of the beam delivery chain. The performance of beam delivery chain are accordingly influenced by many factors in the entire accelerator chain and the vacuum performance is one of key factors steering the beam quality, especially in the synchrotron. In this report, a summary of the simulations done for the entire MedAustron accelerator complex is presented by using so-called Electrical Network Analysis (ENA)