Author: Edward John DawPublisher:
ISBN:
Category :
Languages : en
Pages : 292
Book Description
A Search for Halo Axions
Author: Edward John DawPracticum elementaire statistiek
Author: Improved Radio Frequency Cavity Search for Halo Axions
Author: Daniel Byungyoon YuPublisher:
ISBN:
Category :
Languages : en
Pages : 338
Book Description
The axion is a hypothetical elementary particle and cold dark matter candidate. In this RF cavity experiment, halo axions entering a resonant cavity immersed in a static magnetic field convert into microwave photons, with the resulting photons detected by a low-noise receiver. I present new limits on the axion-to-photon coupling and local axion dark matter halo mass density from a RF cavity axion search in the axion mass range 1.9-2.3 [mu]eV, broadening the search range to 1.9-3.3 [mu]eV. In addition, I report first results from an improved analysis technique, which improves the experiment sensitivity by 13%.
An Improved RF Cavity Search for Halo Axions
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 8
Book Description
The axion is a hypothetical elementary particle and cold dark matter candidate. In this RF cavity experiment, halo axions entering a resonant cavity immersed in a static magnetic field convert into microwave photons, with the resulting photons detected by a low-noise receiver. The ADMX Collaboration presents new limits on the axion-to-photon coupling and local axion dark matter halo mass density from a RF cavity axion search in the axion mass range 1.9-2.3 [mu]eV, broadening the search range to 1.9-3.3 [mu]eV. In addition, we report first results from an improved analysis technique.
A Pilot Radio Telescope Search for Halo Axions
Author: Robert Paul WagnerStatus of the U.S. Dark Matter Axion Search
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
We describe the status of a sensitive search for halo axions with masses in the [mu]eV range. A tunable large-volume and low-loss microwave cavity is operated at low temperature in a strong magnetic field. Resonant Primakoff conversion of axions into photons takes place when the cavity frequency is matched to the axion mass. No positive signal has been found so far, and we are able to exclude hadronic axions as the dominant halo component over a significant axion mass range. Future plans for a detector upgrade are outlined.
Status of the Large-scale Dark-matter Axion Search
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
If axions constitute the dark matter of our galactic halo they can be detected by their conversion into monochromatic microwave photons in a high-Q microwave cavity permeated by a strong magnetic field. A large-scale experiment is under construction at LLNL to search for halo axions in the mass range 1.3 - 13[mu]eV, where axions may constitute closure density of the universe. The search builds upon two pilot efforts at BNL and the University of Florida in the late 1980's, and represents a large improvement in power sensitivity ([approximately]50) both due to the increase in magnetic volume (B[sup 2]V= 14 T[sup 2]m[sup 3]), and anticipated total noise temperature (T[sub n][approximately]3K). This search will also mark the first use of multiple power-combined cavities to extend the mass range accessible by this technique. Data will be analyzed in two parallel streams. In the first, the resolution of the power spectrum will be sufficient to resolve the expected width of the overall axion line, [approximately][bigcirc] (1kHz). In the second, the resolution will be[bigcirc](O.01-1 Hz) to look for extremely narrow substructure reflecting the primordial phase-space of the axions during infall. This experiment will be the first to have the required sensitivity to detect axions, for plausible axion models.
Axions
Author: Markus KusterPublisher: Springer
ISBN: 3540735186
Category : Science
Languages : en
Pages : 248
Book Description
Axions are peculiar hypothetical particles that could both solve the CP problem of quantum chromodynamics and at the same time account for the dark matter of the universe. Based on a series of lectures by world experts in this field held at CERN (Geneva), this volume provides a pedagogical introduction to the theory, cosmology and astrophysics of these fascinating particles and gives an up-to-date account of the status and prospect of ongoing and planned experimental searches.
High Resolution Search for Dark Matter Axions in Milky Way Halo Substructure
Author: Leanne Delma DuffyPublisher:
ISBN:
Category : Dark matter (Astronomy)
Languages : en
Pages : 79
Book Description
ABSTRACT: The axion is one of the leading particle candidates for the universe's dark matter component. Despite possessing very small couplings, the axion's interaction with photons can be utilized to search for it using a microwave cavity detector. The Axion Dark Matter eXperiment (ADMX) uses such a detector to search for axions in our galactic halo. ADMX has recently added a new, high resolution channel to search for axions in discrete flows. ADMX's medium resolution channel searches for axions in the thermalized component of the halo. We review the motivation for the axion and its properties which make it a good dark matter candidate. We also review the arguments for the existence of discrete flows in galactic halos. A flow of discrete axions with small velocity dispersion will appear as a very narrow peak in the output of a microwave cavity detector. A high resolution search can detect such a peak with large signal to noise. We have performed such a search. The details of the high resolution axion search and analysis procedure are presented. In this search, no axion signal was found in the mass range 1.98-2.17 micro-eV. We place upper limits on the density of axions in local discrete flows based on this result.
Axions
Author: Markus KusterPublisher: Springer Science & Business Media
ISBN: 3540735178
Category : Science
Languages : en
Pages : 248
Book Description
Axions are peculiar hypothetical particles that could both solve the CP problem of quantum chromodynamics and at the same time account for the dark matter of the universe. Based on a series of lectures by world experts in this field held at CERN (Geneva), this volume provides a pedagogical introduction to the theory, cosmology and astrophysics of these fascinating particles and gives an up-to-date account of the status and prospect of ongoing and planned experimental searches.