Broken rails remain one of the main causes of railway accidents despite improved rail quality and... more Broken rails remain one of the main causes of railway accidents despite improved rail quality and inspections. Today signalling system track circuits are generally used to detect broken rails, however new signalling systems such as ETCS replace track circuits and therefore new methods are needed to detect broken rails. One promising technology is distributed acoustic sensing (DAS). This paper describes field tests carried out on DAS to evaluate its ability to detect broken rails and the moment when rails break. The testing showed that DAS has good potential for detecting broken rails in both scenarios. The paper describes the tests and results.
L'invention concerne un appareil d'observation binoculaire, notamment des jumelles, prese... more L'invention concerne un appareil d'observation binoculaire, notamment des jumelles, presentant deux trajets faisceaux visuels et un telemetre laser comportant un emetteur laser et un recepteur laser, ainsi qu'un element d'affichage optoelectronique. Une partie du trajet de faisceau de l'emetteur laser est integre dans un premier trajet de faisceau visuel, une partie du trajet de faisceau du recepteur laser etant egalement integre dans le premier trajet de faisceau visuel.
Verfahren zum Unterdrucken eines Echosignals in einer Entfernungsmesseinrichtung (1), welche zumi... more Verfahren zum Unterdrucken eines Echosignals in einer Entfernungsmesseinrichtung (1), welche zumindest einen lichtempfindlichen Empfanger (2) und zumindest eine Laserlichtquelle als Sender (3) aufweist, dadurch gekennzeichnet, dass zumindest ein dem Echosignal entsprechendes Gegensignal (12) erzeugt und einem von dem Empfanger (2) erzeugten Signal (I1) uberlagert wird.
Single ions and crystals of ions are confined in a linear Paul trap and are investigated for quan... more Single ions and crystals of ions are confined in a linear Paul trap and are investigated for quantum information processing. Superpositions of the S1/2 ground state and the long lived D 5/2 state are used to implement a qubit. The ions are optically cooled and fluorescence light at 397 nm on the S1/2 - P1/2 transition is monitored for a
ABSTRACT The widespread use of magneto-optical traps (MOT) and the development of BEC over the la... more ABSTRACT The widespread use of magneto-optical traps (MOT) and the development of BEC over the last 10 years have led to the field of atom optics. This field requires the use of equivalent elements to optical mirrors, lenses and beam splitters. The generation of a large deviation atomic beam splitter is one of the most important goals, as it allows the construction of atom interferometers. Optical methods for achieving these elements are enticing, as the use of laser beams would make it easier to alter parameters of your guides within a vacuum chamber. Recent work has demonstrated the use of optical beams to guide and split atoms from a cold atom source. Here we present novel experimental studies of the optical guiding (in both the red- and blue-detuned regime) of a low-velocity intense source (LVIS) of atoms emanating from a rubidium MOT.
We present details for construction and the operation of a mirror magneto-optical trap for coolin... more We present details for construction and the operation of a mirror magneto-optical trap for cooling and trapping rubidium atoms. For trap operation, only four input laser beams are needed in contrast to the normal six for a standard trap. In excess of 10 atoms have been trapped with this arrangement, with the atomic ensemble only ∼1mm from the surface of a reflective mirror. This trap is highly suited to studies of magnetic guiding and magnetic manipulation of cold atomic ensembles.
We measure the spontaneous emission lifetime of the Dsn level of a single Ca+-ion by Pi- pulse ex... more We measure the spontaneous emission lifetime of the Dsn level of a single Ca+-ion by Pi- pulse excitation and quantum state detection. As the trapped ion is well localized we map the standing-wave cavity vacuum field.
Broken rails remain one of the main causes of railway accidents despite improved rail quality and... more Broken rails remain one of the main causes of railway accidents despite improved rail quality and inspections. Today signalling system track circuits are generally used to detect broken rails, however new signalling systems such as ETCS replace track circuits and therefore new methods are needed to detect broken rails. One promising technology is distributed acoustic sensing (DAS). This paper describes field tests carried out on DAS to evaluate its ability to detect broken rails and the moment when rails break. The testing showed that DAS has good potential for detecting broken rails in both scenarios. The paper describes the tests and results.
L'invention concerne un appareil d'observation binoculaire, notamment des jumelles, prese... more L'invention concerne un appareil d'observation binoculaire, notamment des jumelles, presentant deux trajets faisceaux visuels et un telemetre laser comportant un emetteur laser et un recepteur laser, ainsi qu'un element d'affichage optoelectronique. Une partie du trajet de faisceau de l'emetteur laser est integre dans un premier trajet de faisceau visuel, une partie du trajet de faisceau du recepteur laser etant egalement integre dans le premier trajet de faisceau visuel.
Verfahren zum Unterdrucken eines Echosignals in einer Entfernungsmesseinrichtung (1), welche zumi... more Verfahren zum Unterdrucken eines Echosignals in einer Entfernungsmesseinrichtung (1), welche zumindest einen lichtempfindlichen Empfanger (2) und zumindest eine Laserlichtquelle als Sender (3) aufweist, dadurch gekennzeichnet, dass zumindest ein dem Echosignal entsprechendes Gegensignal (12) erzeugt und einem von dem Empfanger (2) erzeugten Signal (I1) uberlagert wird.
Single ions and crystals of ions are confined in a linear Paul trap and are investigated for quan... more Single ions and crystals of ions are confined in a linear Paul trap and are investigated for quantum information processing. Superpositions of the S1/2 ground state and the long lived D 5/2 state are used to implement a qubit. The ions are optically cooled and fluorescence light at 397 nm on the S1/2 - P1/2 transition is monitored for a
ABSTRACT The widespread use of magneto-optical traps (MOT) and the development of BEC over the la... more ABSTRACT The widespread use of magneto-optical traps (MOT) and the development of BEC over the last 10 years have led to the field of atom optics. This field requires the use of equivalent elements to optical mirrors, lenses and beam splitters. The generation of a large deviation atomic beam splitter is one of the most important goals, as it allows the construction of atom interferometers. Optical methods for achieving these elements are enticing, as the use of laser beams would make it easier to alter parameters of your guides within a vacuum chamber. Recent work has demonstrated the use of optical beams to guide and split atoms from a cold atom source. Here we present novel experimental studies of the optical guiding (in both the red- and blue-detuned regime) of a low-velocity intense source (LVIS) of atoms emanating from a rubidium MOT.
We present details for construction and the operation of a mirror magneto-optical trap for coolin... more We present details for construction and the operation of a mirror magneto-optical trap for cooling and trapping rubidium atoms. For trap operation, only four input laser beams are needed in contrast to the normal six for a standard trap. In excess of 10 atoms have been trapped with this arrangement, with the atomic ensemble only ∼1mm from the surface of a reflective mirror. This trap is highly suited to studies of magnetic guiding and magnetic manipulation of cold atomic ensembles.
We measure the spontaneous emission lifetime of the Dsn level of a single Ca+-ion by Pi- pulse ex... more We measure the spontaneous emission lifetime of the Dsn level of a single Ca+-ion by Pi- pulse excitation and quantum state detection. As the trapped ion is well localized we map the standing-wave cavity vacuum field.
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Papers by gavin Lancaster