Controversy among giants: Young's experiment and loss of fringe visibility at low photon-count levels

2011 ◽  
Author(s):  
William T. Rhodes
2021 ◽  
Vol 503 (2) ◽  
pp. 3032-3043
Author(s):  
Yinhua Wu ◽  
Shasha Chen ◽  
Pengchong Wang ◽  
Shun Zhou ◽  
Yutao Feng ◽  
...  

ABSTRACT The coherent-dispersion spectrometer (CODES) is a new exoplanet detection instrument using the radial velocity (RV) method. This attempts mainly to improve environmental sensitivity and energy utilization by using an asymmetric, common-path Sagnac interferometer instead of a traditional Michelson interferometer. In order to verify its feasibility and to choose the appropriate key parameters to obtain the optimal performance, research on data processing for the design stage of the CODES is performed by systematic simulation and analysis. First, the instrument modelling is carried out for further data analysis according to the principle of the CODES, and the reliability of the model is verified by experiments. Second, the influence of key parameters on fringe visibility is analysed systematically, which provides a certain reference for the choice of the key parameters. Third, the RV inversion method for the CODES is proposed and optimized according to the related analysis results so as to promote RV inversion precision. Finally, the recommended values for the key parameters of the CODES are given. The experimental results show that the data processing error of RV inversion is less than 0.6 m s–1 within the recommended range of key parameters. This indicates that the scheme of the CODES is reasonable and feasible, and that the proposed data processing method is effective and well matched with the instrument design.


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Hayato Ikoma ◽  
Michael Broxton ◽  
Takamasa Kudo ◽  
Gordon Wetzstein

Author(s):  
T. Thuering ◽  
M. Stampanoni

The monochromatic and polychromatic performance of a grating interferometer is theoretically analysed. The smallest detectable refraction angle is used as a metric for the efficiency in acquiring a differential phase-contrast image. Analytical formulae for the visibility and the smallest detectable refraction angle are derived for Talbot-type and Talbot–Lau-type interferometers, respectively, providing a framework for the optimization of the geometry. The polychromatic performance of a grating interferometer is investigated analytically by calculating the energy-dependent interference fringe visibility, the spectral acceptance and the polychromatic interference fringe visibility. The optimization of grating interferometry is a crucial step for the design of application-specific systems with maximum performance.


2021 ◽  
Vol 34 (1) ◽  
pp. 79-88
Author(s):  
Dean Radin ◽  
Helané Wahbeh ◽  
Leena Michel ◽  
Arnaud Delorme

An experiment we conducted from 2012 to 2013, which had not been previously reported, was designed to explore possible psychophysical effects resulting from the interaction of a human mind with a quantum system. Participants focused their attention toward or away from the slits in a double-slit optical system to see if the interference pattern would be affected. Data were collected from 25 people in individual half-hour sessions; each person repeated the test ten times for a total of 250 planned sessions. “Sham” sessions designed to mimic the experimental sessions without observers present were run immediately before and after as controls. Based on the planned analysis, no evidence for a psychophysical effect was found. Because this experiment differed in two essential ways from similar, previously reported double-slit experiments, two exploratory analyses were developed, one based on a simple spectral analysis of the interference pattern and the other based on fringe visibility. For the experimental data, the outcome supported a pattern of results predicted by a causal psychophysical effect, with the spectral metric resulting in a 3.4 sigma effect (p = 0.0003), and the fringe visibility metric resulting in 7 of 22 fringes tested above 2.3 sigma after adjustment for type I error inflation, with one of those fringes at 4.3 sigma above chance (p = 0.00001). The same analyses applied to the sham data showed uniformly null outcomes. Other analyses exploring the potential that these results were due to mundane artifacts, such as fluctuations in temperature or vibration, showed no evidence of such influences. Future studies using the same protocols and analytical methods will be required to determine if these exploratory results are idiosyncratic or reflect a genuine psychophysical influence.


2018 ◽  
Vol 33 (4) ◽  
pp. 325-333 ◽  
Author(s):  
Blangat Dileep ◽  
Ravi Mana ◽  
Karunakara Nerugundi ◽  
Sangameshwar Managanvi ◽  
Raj Tripathi

In pressurized heavy water reactors, leaks from D2O primary coolant and moderator to H2O secondary coolant and other light-water systems in heat exchangers cannot be completely ruled out. High cost of D2O demands that its loss should be prevented to maximum extent possible. Traditionally D2O leak detection and identification of leaky heat exchanger is carried out by measurement of tritium activity in H2O. Since tritium emits low energy beta radiation, its concentration in H2O is measured by mixing it with liquid scintillation solution in a definite proportion in counting vial and counted in a Liquid Scintillation Analyzer. It is very sensitive method for leak detection, but identification of leaky heat exchanger is time consuming and may require low power operation or reactor shut down. In the new method, high energy beta emitting fission products, which emit Cherenkov photons in H2O, were used as the tracer. H2O was poured in 20 mL plastic vials without scintillator and counted on Liquid Scintillation Analyzer. D2O leak was identified by comparing the Cherenkov photon count rate with that of the blank. A discrimination ratio significantly higher than average Cherenkov photon count rate for all heat exchangers was used to identify the leaky one. The technique has advantageous over existing method of D2O leak detection, such as, (1) scintillation chemicals are not required (2) low power operation or reactor shut down is not required for identifying the leaky heat exchanger (3) no generation of radioactive chemical waste (4) on-power leak identification reduces generation of radioactive liquid waste.


2021 ◽  
Author(s):  
Joshua Snyder ◽  
Christopher Bailey ◽  
Walter Schmoll ◽  
Steven Zuraski ◽  
Elizabeth Beecher
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