Simultaneous Measurement Of Position Research Articles

Development of a hybrid single-photon imaging detector with embedded CMOS pixelated anode

The development of a single-photon detector based on a vacuum tube, transmission photocathode, microchannel plate and CMOS pixelated read-out anode is presented. This imager will be capable of detecting up to 1 billion photons per second over an area of 7 cm2, with simultaneous measurement of position and time with resolutions of about 5 microns and few tens of picosecond, respectively. The detector has embedded pulse-processing electronics with data-driven architecture, based on the Timepix4 ASIC, producing up to 160 Gb/s data that will be handled by a high-throughput FPGA-based external electronics and data acquisition system. These performances will enable significant advances in particle physics, life sciences, quantum optics or other emerging fields where the detection of single photons with excellent timing and position resolutions are simultaneously required.

Development of a single-photon imaging detector with pixelated anode and integrated digital read-out

We present the development of a single-photon detector and the connected read-out electronics. This “hybrid” detector is based on a vacuum tube, transmission photocathode, microchannel plate and a pixelated CMOS read-out anode encapsulating the analog and digital-front end electronics. This assembly will be capable of detecting up to 109 photons per second with simultaneous measurement of position and time.The pixelated read-out anode used is based on the Timepix4 ASIC (65 nm CMOS technology) designed in the framework of the Medipix4 collaboration. This ASIC is an array of 512 × 448 pixels distributed on a 55 μm square pitch, with a sensitive area of ∼7 cm2. It features 50–70 e− equivalent noise charge, a maximum rate of 2.5 Ghits/s, and allows to time-stamp the leading-edge time and to measure the Time-over-Threshold (ToT) for each pixel. The pixel-cluster position combined with its ToT information will allow to reach 5–10 μm position resolution. This information can also be used to correct for the leading-edge time-walk achieving a timing resolution of the order of 10 ps.The detector will be highly compact thanks to the encapsulated front-end electronics allowing local data processing and digitization. An FPGA-based data acquisition board, placed far from the detector, will receive the detector hits using 16 electro-optical links operated at 10.24 Gbps. The data acquisition board will decode the information and store the relevant data in a server for offline analysis.These performance will allow significant advances in particle physics, life sciences, quantum optics or other emerging fields where the detection of single photons with excellent timing and position resolutions are simultaneously required.

Single-photon imaging detector with \U0001d4aa(10) ps timing and sub-10 μm position resolutions

We present the concept of a single-photon imager capable of detecting up to 109 photons per second with simultaneous measurements of position (5–10 μm resolution) and time (few tens of picosecond resolution) for each individual photon over an active area of 7 cm2. The detector is based on a “hybrid” concept: a vacuum tube, with a transparent input window on which a suitable photocathode material is deposited, a micro-channel plate and a pixelated read-out anode designed in 65 nm CMOS technology. These figures of merit will open many important applications allowing significant advances in particle physics, life sciences or other emerging fields where the detection of single photons with excellent timing and position resolutions are simultaneously required.

Beam position monitor gate functionality implementation and applications

We introduce a novel technique to implement gate functionality for the beam position monitors (BPM) at the National Synchrotron Light Source II (NSLS-II). The functionality, now implemented in FPGA, allows us to acquire two separated bunch-trains’ synchronized turn-by-turn (TBT) data simultaneously with the NSLS-II in-house developed BPM system. The gated position resolution is improved about 3 times by narrowing the sampling width. Experimentally we demonstrated that the machine lattice could be transparently characterized with the gated TBT data of a short diagnostic bunch-train Cheng et al., 2017; Li et al., 2017. Other applications, for example, precisely characterizing storage ring impedance/wake-field through recording the beam positions of two separated bunch trains has been experimentally demonstrated.•Gated BPM signal processing improves the position resolution.•Transparent lattice measurement using the gate function with diagnostic bunches.•Collective effect study with simultaneous position measurement from two gates.

The Uncertainty Principle in Terms of Isoperimetric Inequalities

Simultaneous measurements of position and momentum are considered in $n$ dimensions. We find, that for a particle whose position is strictly localized in a compact domain $D\subset \mathbb{R}^n$ (spatial uncertainty) with non-empty boundary, the standard deviation of its momentum is sharply bounded by $\sigma_p \geq \lambda_1^{1/2}\hbar$, while $\lambda_1$ is the first Dirichlet eigenvalue of the Laplacian on $D$.

The Gaussian-smoothed Wigner function and its application to precision analysis

We study a class of phase-space distribution functions that is generated from a Gaussian convolution of the Wigner distribution function. This class of functions represents the joint count probability in simultaneous measurements of position and momentum. We show that, using these functions, one can determine the expectation value of a certain class of operators accurately, even if measurement data performed only with imperfect detectors are available. As an illustration, we consider the eight-port homodyne detection experiment that performs simultaneous measurements of two quadrature amplitudes of a radiation field.

Simultaneous measurement of position and color of single fluorescent emitters using diffractive optics

We propose a method for simultaneously measuring the position and emission color of single fluorescent emitters based on the use of a large pitch diffraction grating in the emission light path. The grating produces satellite spots adjacent to the main spot; the relative distance between the spots is a measure for the emission wavelength. We present proof-of-principle experiments on beads and mixtures of quantum dots using a spatial light modulator for making a programmable diffraction grating. A wavelength precision of around 10nm can be achieved for 1000 signal photons and practical background levels, while maintaining a localization precision of around 10nm.

The AMS silicon tracker: Construction and performance

Eight layers of double sided silicon microstrip sensors immersed in a 0.8 T magnetic field constitute the core of the AMS-02 apparatus. In each layer, simultaneous measurements of position and energy loss in silicon are performed along the particle trajectory. With its high spatial resolution, the silicon tracker will determine the rigidity ( R) and the charge sign of particles up to several TVs, with a relative resolution 2.5% at R < 100 GV . The low noise and wide dynamic range of the silicon readout electronics allow to exploit the energy loss measurements to determine the particle absolute charge for nuclei up to Fe. The AMS tracker construction has been completed and it will be integrated into the AMS experiment during the 2007. The performances of the silicon detectors observed under various beam tests are presented focusing on the spatial resolution and on the charge separation capability.

Optimal Joint Measurements of Position and Momentum

The distribution of measured values formaximally accurate, unbiased simultaneous measurementsof position and momentum is investigated. It is shown,that if the measurement is retrodictively optimal, then the distribution of results is given by theinitial state Husimi function (or Q-representation). Ifthe measurement is predictively optimal, then thedistribution of results is related to the final state anti-Husimi function (or P-representation). Thesignificance of this universal property for theinterpretation of the Husimi function isdiscussed.

Gallium arsenide strip detectors for particle identification by the triple measurement of time of flight, position and specific ionization

A design of a gallium arsenide strip detector performing the triple, simultaneous measurements of position, dE/dx and time of flight is presented (LATIN project). The expected time. energy and position resolutions are given in various experimental conditions. A precursor of this instrument made of silicon strip detectors has been constructed and operated at a temperature of −55° C and tested with a pion beam of 4.0 GeV/c. The measured time resolution is 61±7 ps. Cosmic-ray experiments in space may benefit from this kind of instruments for nuclide and particle identification.

Concept of Experimental Accuracy and Simultaneous Measurements of Position and Momentum

The concept of experimental accuracy isinvestigated in the context of the unbiased jointmeasurement processes defined by Arthurs and Kelly. Adistinction is made between the errors of retrodictionand prediction. Four error-disturbancerelationships are derived, analogous to the singleerror-disturbance relationship derived by Braginsky andKhalili in the context of single measurements ofposition only. A retrodictive and a predictive error-errorrelationship are also derived. The connection betweenthese relationships and the extended uncertaintyprinciple of Arthurs and Kelly is discussed. Thesimilarities and differences between the quantum mechanicaland classical concepts of experimental accuracy areexplored. It is argued that these relationships providegrounds for questioning Uffink's conclusion that the concept of a simultaneous measurement ofnoncommuting observables is not fruitful.

State change, quantum probability, and information in operational phase-space measurement

State change, quantum probability, and information gain in the operational phasespace measurement are formulated by means of positive operator-valued measure (POVM) and operation. The properties of the operational POVM and its marginal POVM which yield the quantum probability distributions of the measurement outcomes obtained by the operational phase-space measurement are investigated. The Naimark extension of the operational POVM can be expressed in terms of the relative-position states and the relative-momentum states in the extended Hilbert space. An observable quantity measured in the operational phase-space measurement becomes a fuzzy or unsharp observable. The state change of a physical system caused by the operational phase-space measurement is described by the operation which is obtained explicitly for the position and momentum measurements and for the simultaneous measurement of position and momentum. Using the results, the entropy change of the measured physical system and the information gain in the operational phase-space measurement are investigated. It is found that the average value of the entropy change is equal to the Shannon mutual information extracted from the outcomes exhibited by the measurement apparatus.

A scheme for the simultaneous measurement of atomic position and momentum

We propose an optical scheme for the simultaneous measurement of the position and momentum of a single atom. The scheme involves the coupling of the atom of two light fields with different spatial and polarization characteristics. The proposed technique is closely related to the Arthurs-Kelly measurement scheme; the principal difference is that in the present case the values of the position and momentum are inferred from phase shifts in electromagnetic fields rather than from shifts in the position of a pointer.

On the simultaneous measurement of position and momentum: Naimark embeddings and projections

Single and double meter simultaneous measurements of a harmonic oscillator are reviewed and compared. Naimark extensions are constructed and relevant projection properties are exhibited for both cases. The theory is extended to the simultaneous measurement of squeezed position and momentum measurements.

Proposed experimental test of wave packet reduction and the uncertainty principle

A practical experiment using coincidence techniques is suggested to test the validity of the following concepts:(1) wave packet reduction and(2) the measurement-uncertainty principle for position and momentum. The suggested experiment uses the time-of-flight method to determine an electron's momentum and a coincident photon, emitted from a system excited by the electron, to determine its initial position. It is shown that this method does constitute a simultaneous measurement of position and momentum for a single system. Also, it is pointed out that the traditional statement of the measurementuncertainty principle must be slightly modified even within the Copenhagen interpretation of quantum mechanics.

The Circular Test For Industrial Robots And ItsInterpretation

New applications of industrial robots and increasing qualityand productivityrequirements cause a demand for quick and precise robot movements. ISO 9283 defines path characteristics to evaluate dynamic measurements, furthermore, ISO 230-4 gives a standard [1] for the circular test. With a new device, developed at the Department of Production Engineering at Graz University of Technology, simultaneous measurement of position and orientation of the robot's end-effector during circular and freeform-tests is possible.

ON A THEORY OF MEASUREMENT OF INCOMPATIBLE OBSERVABLES IN QUANTUM MECHANICS

The empirical meaning of the simultaneity of measurement of several observables is carefully analyzed. General criteria sufficient to guarantee the internal consistency of a framework including simultaneous measurements of incompatible observables are put forward. The case is illustrated with the example of simultaneous measurements of position and momenta of particles in quantum mechanics. It is pointed out that, in general, the outcome of measurements of incompatible observables cannot be described statistically by means of the probability measures of mathematical statistics, which have primarily been introduced only with compatible observables in mind. The concept of complex probability measure is put forward. A generalization of the current interpretation of quantum mechanics is proposed that would also include the case of incompatible observables, by taking advantage of the concept of complex probability measure.