Related Experiment Video
Updated: Jul 18, 2026
06:14
Simulating Imaging of Large Scale Radio Arrays on the Lunar Surface
Published on: July 30, 2020
Detecting solar axions using Earth's magnetic field.
Hooman Davoudiasl1, Patrick Huber
1Department of Physics, University of Wisconsin, Madison, Wisconsin 53706, USA.
Physical Review Letters
|December 13, 2006
Summary
Solar axion conversion to photons in Earth's magnetosphere can create a detectable X-ray flux. This study proposes a new method to probe axion properties, exceeding current laboratory sensitivities.
Area of Science:
- Astrophysics
- Particle Physics
Background:
- Axions are hypothetical particles proposed as dark matter candidates.
- Solar axions can convert to photons within planetary magnetospheres.
Purpose of the Study:
- To investigate the potential for detecting solar axions via photon conversion in Earth's magnetosphere.
- To establish a new experimental approach for probing axion-photon coupling.
Main Methods:
- Simulating solar axion to photon conversion within the Earth's magnetosphere.
- Proposing the use of a low-Earth-orbit X-ray detector with a large effective area.
- Targeting the detector towards the solar core for optimal signal detection.
Main Results:
- Solar axion-photon conversion can generate a measurable X-ray flux (approx. 4 keV) on Earth's night side.
- The large magnetized volume of the magnetosphere compensates for the weak magnetic field.
- Sensitivity to photon-axion coupling down to 10(-11) GeV-1 is achievable for axion masses < 10(-4) eV within one year.
Conclusions:
- This method offers a novel way to detect solar axions.
- The proposed X-ray detection strategy provides an order of magnitude improvement over current laboratory limits.
- The study opens new avenues for exploring fundamental physics with astrophysical observations.
Related Concept Videos
01:28Magnetic Fields
A moving charge or a current creates a magnetic field in the surrounding space, in addition to its electric field. The magnetic field exerts a force on any other moving charge or current that is present in the field. Like an electric field, the magnetic field is also a vector field. At any position, the direction of the magnetic field is defined as the direction in which the north pole of a compass needle points.
A magnetic field is defined by the force that a charged particle experiences...
A magnetic field is defined by the force that a charged particle experiences...
01:18Magnetic Field of a Solenoid
A solenoid is a conducting wire coated with an insulating material, wound tightly in the form of a helical coil. The magnetic field due to a solenoid is the vector sum of the magnetic fields due to its individual turns. Therefore, for an ideal solenoid, the magnetic field within the solenoid is directly proportional to the number of turns per unit length and the current. Conversely, the magnetic field outside the solenoid is zero.
Consider a solenoid with 100 turns wrapped around a cylinder of...
Consider a solenoid with 100 turns wrapped around a cylinder of...
01:19Magnetic Field Lines
The representation of magnetic fields by magnetic field lines is very useful in visualizing the strength and direction of the magnetic field. Each of the magnetic field lines forms a closed loop. The field lines emerge from the north pole (N), loop around to the south pole (S), and continue through the bar magnet back to the north pole.
Magnetic field lines follow several hard-and-fast rules:
Magnetic field lines follow several hard-and-fast rules:
01:25Magnetic Field due to Moving Charges
A stationary charge creates and interacts with the electric field, while a moving charge creates a magnetic field.
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
01:30Magnetism
Magnets are commonly found in everyday objects, such as toys, hangers, elevators, doorbells, and computer devices. Experimentation on these magnets shows that all magnets have two poles: one is labeled north (N) and the other south (S). Magnetic poles repel if they are alike and attract if unlike. Moreover, both poles of a magnet attract unmagnetized pieces of iron.
An individual magnetic pole cannot be isolated. No matter how small, every piece of a magnet contains a north pole and a south...
An individual magnetic pole cannot be isolated. No matter how small, every piece of a magnet contains a north pole and a south...
01:23Energy In A Magnetic Field
If a magnetic field is sustained, there must be a current in a closed circuit or loop, implying some energy has been spent in creating the field. If this energy is not dissipated via the circuit's resistance, it is stored in the field.
Take an ideal inductor with zero resistance. Although it's practically impossible, assume that the coil's resistance is so small that it is practically negligible. The loss of the field's energy to dissipate thermal energy (or heat) is thus negligible.
The energy...
Take an ideal inductor with zero resistance. Although it's practically impossible, assume that the coil's resistance is so small that it is practically negligible. The loss of the field's energy to dissipate thermal energy (or heat) is thus negligible.
The energy...