A status report is given on experiment 91-12, which is the first internal target experiment perfo... more A status report is given on experiment 91-12, which is the first internal target experiment performed at the internal target facility of NIKHEF. The aim of this experiment is to measure the asymmetry in the (e,e'p) reaction from a tensor polarized deuterium target with unpolarized electrons. An update on the experimental setup and results of an extensive set of test
We report on the first measurement of spin-correlation parameters in quasifree electron scatterin... more We report on the first measurement of spin-correlation parameters in quasifree electron scattering from vector-polarized deuterium. Polarized electrons were injected into an electron storage ring at a beam energy of 720 MeV. A Siberian snake was employed to preserve longitudinal polarization at the interaction point. Vector-polarized deuterium was produced by an atomic beam source and injected into an openended cylindrical cell, internal to the electron storage ring. The spin correlation parameter A V ed was measured for the reaction 2 H( e, e ′ n)p at a four-momentum transfer squared of 0.21 (GeV/c) 2 from which a value for the charge form factor of the neutron was extracted.
The Charge Form Factor of the Neutron from the Reaction ²{rvec H}({rvec e},eâ²n)p
Physical Review Letters - PHYS REV LETT, 1999
We report on the first measurement of spin-correlation parameters in quasifree electron scatterin... more We report on the first measurement of spin-correlation parameters in quasifree electron scattering from vector-polarized deuterium. Polarized electrons were injected into an electron storage ring at a beam energy of 720 MeV. A Siberian snake was employed to preserve longitudinal polarization at the interaction point. Vector-polarized deuterium was produced by an atomic beam source and injected into an open-ended cylindrical cell, internal to the electron storage ring. The spin correlation parameter A{sub ed}{sup V} was measured for the reaction ²{rvec H}({rvec e},eâ²n)p at a four-momentum transfer squared of 0.21 (GeV/c)² from which a value for the charge form factor of the neutron was extracted.
We report on first measurements with polarized electrons stored in a medium-energy ring and with ... more We report on first measurements with polarized electrons stored in a medium-energy ring and with a polarized internal target. Polarized electrons were injected at 442 MeV (653 MeV), and a partial (full) Siberian snake was employed to preserve the polarization. Longitudinal polarization at the interaction point and polarization lifetime of the stored electrons were determined with laser backscattering. Spin observables were measured for electrodisintegration of polarized 3 He, with simultaneous detection of scattered electrons, protons, neutrons, deuterons, and 3 He nuclei, over a large phase space. PACS numbers: 24.70. + s, 25.30.Fj, 29.20.Dh, 29.27.Hj In the scattering of leptons from hadronic targets, the leptonic part of the interaction is well understood, allowing one to focus on the strong-interaction vertex and the underlying structure and dynamics of the nucleus. The ultimate probe consists of spin-dependent scattering with polarized leptons and polarized targets [1], and the last decade has seen a large effort devoted to the realization of such experiments.
Measurement of Spin Observables in the^ 3He (e, e'p) and^ 3He (e, e'd) reactions
Measurement of spin observables in the ^3He(e,e'p) an... more Measurement of spin observables in the ^3He(e,e'p) and ^3He(e,e'd) reactions have been carried out at the Internal Target Facility of NIKHEF with a 720 MeV stored electron beam having a longitudinal polarization of 65% and an average current of 80 mA. The average target polarization was 45% with a thickness of 5×10^14 atoms/cm^2. The scattered electrons were detected in a
Coherent pi^0 electro-production on a composite nucleus is an excellent testing ground for theori... more Coherent pi^0 electro-production on a composite nucleus is an excellent testing ground for theories of resonance propagation in the nuclear medium. At energy transfers of 200-400 MeV, the properties of the Delta(1232) resonance are expected to be noticeably modified by interactions with the nucleons. This reaction was studied on ^4He and polarized ^3He at the Internal Target Facility of NIKHEF by scattering electrons of 700 MeV from isotopically pure gases of ^3,4He atoms. The detection of neutral pions was avoided by using a recoil detector for the very low-energy recoiling helium nuclei. Results will be compared with recent model calculations.
The Charge Form Factor of the Neutron from the Reaction ²{rvec H}({rvec e},eâ²n)p
Physical Review Letters - PHYS REV LETT, 1999
We report on the first measurement of spin-correlation parameters in quasifree electron scatterin... more We report on the first measurement of spin-correlation parameters in quasifree electron scattering from vector-polarized deuterium. Polarized electrons were injected into an electron storage ring at a beam energy of 720 MeV. A Siberian snake was employed to preserve longitudinal polarization at the interaction point. Vector-polarized deuterium was produced by an atomic beam source and injected into an open-ended cylindrical cell, internal to the electron storage ring. The spin correlation parameter A{sub ed}{sup V} was measured for the reaction ²{rvec H}({rvec e},eâ²n)p at a four-momentum transfer squared of 0.21 (GeV/c)² from which a value for the charge form factor of the neutron was extracted.
A status report is given on experiment 91-12, which is the first internal target experiment perfo... more A status report is given on experiment 91-12, which is the first internal target experiment performed at the internal target facility of NIKHEF. The aim of this experiment is to measure the asymmetry in the (e,e'p) reaction from a tensor polarized deuterium target with unpolarized electrons. An update on the experimental setup and results of an extensive set of test
We report on the first measurement of spin-correlation parameters in quasifree electron scatterin... more We report on the first measurement of spin-correlation parameters in quasifree electron scattering from vector-polarized deuterium. Polarized electrons were injected into an electron storage ring at a beam energy of 720 MeV. A Siberian snake was employed to preserve longitudinal polarization at the interaction point. Vector-polarized deuterium was produced by an atomic beam source and injected into an openended cylindrical cell, internal to the electron storage ring. The spin correlation parameter A V ed was measured for the reaction 2 H( e, e ′ n)p at a four-momentum transfer squared of 0.21 (GeV/c) 2 from which a value for the charge form factor of the neutron was extracted.
The Charge Form Factor of the Neutron from the Reaction ²{rvec H}({rvec e},eâ²n)p
Physical Review Letters - PHYS REV LETT, 1999
We report on the first measurement of spin-correlation parameters in quasifree electron scatterin... more We report on the first measurement of spin-correlation parameters in quasifree electron scattering from vector-polarized deuterium. Polarized electrons were injected into an electron storage ring at a beam energy of 720 MeV. A Siberian snake was employed to preserve longitudinal polarization at the interaction point. Vector-polarized deuterium was produced by an atomic beam source and injected into an open-ended cylindrical cell, internal to the electron storage ring. The spin correlation parameter A{sub ed}{sup V} was measured for the reaction ²{rvec H}({rvec e},eâ²n)p at a four-momentum transfer squared of 0.21 (GeV/c)² from which a value for the charge form factor of the neutron was extracted.
We report on first measurements with polarized electrons stored in a medium-energy ring and with ... more We report on first measurements with polarized electrons stored in a medium-energy ring and with a polarized internal target. Polarized electrons were injected at 442 MeV (653 MeV), and a partial (full) Siberian snake was employed to preserve the polarization. Longitudinal polarization at the interaction point and polarization lifetime of the stored electrons were determined with laser backscattering. Spin observables were measured for electrodisintegration of polarized 3 He, with simultaneous detection of scattered electrons, protons, neutrons, deuterons, and 3 He nuclei, over a large phase space. PACS numbers: 24.70. + s, 25.30.Fj, 29.20.Dh, 29.27.Hj In the scattering of leptons from hadronic targets, the leptonic part of the interaction is well understood, allowing one to focus on the strong-interaction vertex and the underlying structure and dynamics of the nucleus. The ultimate probe consists of spin-dependent scattering with polarized leptons and polarized targets [1], and the last decade has seen a large effort devoted to the realization of such experiments.
Measurement of Spin Observables in the^ 3He (e, e'p) and^ 3He (e, e'd) reactions
Measurement of spin observables in the ^3He(e,e'p) an... more Measurement of spin observables in the ^3He(e,e'p) and ^3He(e,e'd) reactions have been carried out at the Internal Target Facility of NIKHEF with a 720 MeV stored electron beam having a longitudinal polarization of 65% and an average current of 80 mA. The average target polarization was 45% with a thickness of 5×10^14 atoms/cm^2. The scattered electrons were detected in a
Coherent pi^0 electro-production on a composite nucleus is an excellent testing ground for theori... more Coherent pi^0 electro-production on a composite nucleus is an excellent testing ground for theories of resonance propagation in the nuclear medium. At energy transfers of 200-400 MeV, the properties of the Delta(1232) resonance are expected to be noticeably modified by interactions with the nucleons. This reaction was studied on ^4He and polarized ^3He at the Internal Target Facility of NIKHEF by scattering electrons of 700 MeV from isotopically pure gases of ^3,4He atoms. The detection of neutral pions was avoided by using a recoil detector for the very low-energy recoiling helium nuclei. Results will be compared with recent model calculations.
The Charge Form Factor of the Neutron from the Reaction ²{rvec H}({rvec e},eâ²n)p
Physical Review Letters - PHYS REV LETT, 1999
We report on the first measurement of spin-correlation parameters in quasifree electron scatterin... more We report on the first measurement of spin-correlation parameters in quasifree electron scattering from vector-polarized deuterium. Polarized electrons were injected into an electron storage ring at a beam energy of 720 MeV. A Siberian snake was employed to preserve longitudinal polarization at the interaction point. Vector-polarized deuterium was produced by an atomic beam source and injected into an open-ended cylindrical cell, internal to the electron storage ring. The spin correlation parameter A{sub ed}{sup V} was measured for the reaction ²{rvec H}({rvec e},eâ²n)p at a four-momentum transfer squared of 0.21 (GeV/c)² from which a value for the charge form factor of the neutron was extracted.
Proper and consistent time keeping is crucial for C-ITS applications, as any inconsistencies in t... more Proper and consistent time keeping is crucial for C-ITS applications, as any inconsistencies in the timing information can directly affect the applications. As an example, if the timing information in a message would be misinterpreted by 1s, that would easily lead in an emergency breaking scenario of a highway to a misinterpretation of the position of a vehicle of 30m and thus to a complete misinterpretation of a potentially dangerous situation. Therefore, unambiguous standards for timing and reliable implementations are crucial for a proper functioning of C-ITS applications. In this white paper, the timing aspects relevant for C-ITS stations will be discussed. First, the standardization aspects will be discussed, and secondly the implementation aspects.
This paper describes the specifications for interoperability of C-ITS services using hybrid commu... more This paper describes the specifications for interoperability of C-ITS services using hybrid communication as developed by the European project InterCor. Based on a high-level system description interfaces are defined to enable interoperability as required for C-ITS services offered to road users by involved stake holders, i.e. national road authorities, automotive industry, traffic information providers and others. The services Road works warning, In vehicle signage, Green light optimal speed advisory, and Probe Vehicle Data have been used to describe the high-level systems for these I2V services and to determine the requirements for the interface to support both short-range ad-hoc communication and long-range communication via mobile networks with a back-office interface. Based on the requirements, technical specifications that have been defined, implemented and tested in the involved European Union Member States of InterCor are presented.
IEEE 15th Workshop on Positioning, Navigation and Communications, 2018
High accuracy positioning systems are crucial for automated driving. Real-Time Kinematic (RTK) po... more High accuracy positioning systems are crucial for automated driving. Real-Time Kinematic (RTK) positioning is widely used in high-precision positioning and navigation applications, and can also be used in automated driving use cases. Little public information is available, however, on how the accuracy deteriorates as a function of the distance between the base station and the vehicle. This paper presents a practical approach and experimental results to characterize accuracy effects from increasing RTK operating range.
For the development of cooperative and automated vehicular systems, real-world data plays an impo... more For the development of cooperative and automated vehicular systems, real-world data plays an important role. This paper describes five car labs that have been developed to collect such data sets quickly and accurately, thereby supporting the development of sensors, algorithms, and to perform impact assessment of such systems. Requirements on the data collection system are derived and the data collection system developed is described. Some examples of data collected and their use are also presented.
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Papers by Igor Passchier