Search results for "accelerator"

New evidence on accelerator performance based on funding and location

2020

Seed accelerators (SAs) appear as a more advanced version of business incubators. These for-profit organizations in exchange of equity, help setting new start-ups by providing mentoring and funding during its first months. Due to their emergent nature, the impact and expectations of SAs remains largely unknown. Therefore, the purpose of this study is to throw new light on this field by empirically assessing for the first time the performance and prospects of these organizations through a survey of 116 SAs.,A model based on the Business Incubators literature is built with four categories covering size, location, age and profitability variables, leading to two hypotheses to be tested empirica…

LA COLLABORAZIONE MULTILAB: LO STUDIO “PSA 006 TROLLEY PROBLEM”

Improved limit on the directly measured antiproton lifetime

2017

Continuous monitoring of a cloud of antiprotons stored in a Penning trap for 405 days enables us to set an improved limit on the directly measured antiproton lifetime. From our measurements we extract a storage time of $3.15\times {10}^{8}$ equivalent antiproton-seconds, resulting in a lower lifetime limit of ${\tau }_{\bar{{\rm{p}}}}\gt 10.2\,{\rm{a}}$ with a confidence level of $68 \% $. This result improves the limit on charge-parity-time violation in antiproton decays based on direct observation by a factor of 7.

Preparation of negative ion beams for the determination of the electron affinity of polonium by laser photodetachment

2021

A letter of intent submitted to the ISOLDE and Neutron-Time-of-flight Committee (INTC) at CERN to prepare the negative ion beam as a step towards measuring the electron affinity of polonium at CRIS (ISOLDE).

Tin-DNA complexes investigated by nuclear inelastic scattering of synchrotron radiation

2005

Nuclear inelastic scattering (NIS) of synchrotron radiation has been used to investigate the dynamics of tin ions chelated by DNA. Theoretical NIS spectra have been simulated with the help of density functional theory (DFT) calculations using 12 models for different binding sites of the tin ion in (CH3)Sn(DNAPhosphate)2. The simulated spectra are compared with the measured spectrum of the tin-DNA complex.

Protonation of 3-aminopyrroles

1987

Abstract The protonation of 3-aminopyrroles has been investigated using H and 13C n.m.r. spectroscopy. The spectral data are compatible with predominant protonation of the amino group with no evidence for protonation of the pyrrole ring.

Crack bifurcations in a strained lattice

1996

Dynamic crack propagation in a strained, granular, and brittle material is investigated by modeling the material as a lattice network of elastic beams. By tuning the strain and the ratio of axial to bending stiffness of the beams, a crack propagates either straight, or it branches, or it bifurcates. The crack tip velocity is calculated approximately for cracks that propagate straight. In a bifurcated crack the number of broken beams follows a scaling law. The shape of the branches is found to be the same as in recent experiments.

Cooling and slowing of trapped antiprotons below 100 meV

1989

Electron cooling of trapped antiprotons allows their storage at energies 10 million times lower than is available in any antiproton storage ring. More than 60 000 antiprotons with energies from 0 to 3000 eV are stored in an ion trap from a single pulse of 5.9-MeV antiprotons from LEAR. Trapped antiprotons maintain their initial energy distribution over a storage lifetime exceeding 50 h unless allowed to collide with a cold buffer gas of trapped electrons, where- upon they cool dramatically to 1 eV in tens of seconds. The cooled antiprotons can be stacked into a harmonic potential well suited for long-term storage and precision measurements.

Cryogenic Particle Accumulation In ATRAP And The First Antihydrogen Production Within A Magnetic Gradient Trap For Neutral Antimatter

2008

ATRAP has made many important improvements since CERN's Antiproton Decelerator (AD) was restarted in 2006. These include substantial increases in the number of positrons (e+) and antiprotons (Pbars) used to make antihydrogen (Hbar) atoms, a new technique for loading electrons (e−) that are used to cool Pbars and e+, implementation of a completely new, larger and more robust apparatus in our second experimental zone and the inclusion of a quadrupole Ioffe trap intended to trap the coldest Hbar atoms produced. Using this new apparatus we have produced large numbers of Hbar atoms within a Penning trap that is located within this quadrupole Ioffe trap using a new technique which shows promise f…

Antihydrogen production in a combined trap

1993

In this paper we study the properties of a Paul trap with a superimposed magnetic field (combined trap) and discuss the possibility of using this trap to simultaneously store positrons and antiprotons to form antihydrogen.