This document summarizes several existing and proposed experiments that aim to directly detect dark matter particles known as WIMPs (Weakly Interacting Massive Particles) and axions. It describes experiments using various detection methods like neutrino detectors, scintillation detectors, and gaseous time projection chambers located underground to shield experiments from cosmic rays. The document also provides brief descriptions of some experimental results as of 2012.

1. Presented by Morgan Catha
Physics 422, Fall 2012

2.  WIMPs are hypothesized to be captured by Sol.
 Subsequent annihilations may produce neutrinos.
 These excess neutrinos might be detectable from Earth.
 Existing neutrino detectors are well suited for this search.

4. One of 5160 Digital Optical Modules installed below the Antarctic ice to depths of
2450 meters. The photomultiplier tubes within the pressure spheres record Cherenkov
radiation from muons created by neutrino interactions in the ice. Data is transmitted
to the surface along cables for storage and processing.

5. Antares is mounted in the Mediterranean Sea near Toulon, France. Its design is
similar to that of IceCube – photomultiplier tubes mounted within pressure spheres
submerged within a shielding medium, detecting Cherenkov radiation from muons
created by interactions of neutrinos emerging upward through the Earth’s crust.

6. The Kamioka Observatory sits below 1000 meters
of rock in the Hida Mountains of central Japan.
The neutrino detector consists of a cylindrical
chamber lined with 11,146 Hamamatsu PMTs and
filled with 50,000 tons of pure water. In 2001, a chain reaction caused over half of the
tubes immersed in water to implode. The tubes now all have acrylic shields.

8. The Fermi gamma ray space telescope was
The Fermi space telescope was
launched by NASA
launched by NASA in 2008 to gather
data on cosmic gamma rays. This craft
may be able to observe gamma rays created by WIMP annihilations in the galactic halo.

10. PICASSO, located at SNOLAB, is a direct WIMP detector that uses superheated
droplets of perfluorobutane suspended in an elastic polymer. When a WIMP collides
with an atom in one of the droplets, the atom recoils and heats up the bubble,
triggering an explosive conversion to vapor. The resulting acoustic pulse is picked up
by piezoelectric sensors mounted around the gel.

11. DEAP-3600, currently under construction at
SNOLAB, uses a volume of liquid argon as a
scintillation material to detect WIMPs. Like the
Neutrino detectors, it uses an array of PMTs to
detect the light resulting from collision events.

12. XENON100 is a scintillation detector located at Gran Sasso underground laboratory in
Italy. It uses 161 kg of liquid Xenon, which has similar ionization and scintillation
properties to Argon. The measured ratio of ionization to scintillation allows
Researchers to determine what type of particle interacted within the liquid.

13. DRIFT II uses a carbon disulphide gaseous time projection chamber to detect
ionizations caused by WIMP collisions. A 3-D map of the ionization left by the
scattering event is constructed by measuring the times at which the ions arrive at the
anode endplate.

14. CDMS II, located in the Soudan Mine Underground Laboratory in Minnesota, uses
ultra cold germanium crystals to detect ionization and phonons produced by WIMP
interactions. When a WIMP collides with a nucleus in the crystal, the resulting
rebound causes the entire crystal lattice to vibrate. Microscopic strips of tungsten at
the edge of the crystal are held at the transition point between superconducting mode
and normal. The phonon energy transferrals to the tungsten are thus registered as
large changes in resistivity. This apparatus is held at as low as 10 mK temperature.

15. Joseph Giannetti’s mural next to the MINOS neutrino detector in Soudan Mine.

17. CAST consists of a nine tesla dipole magnet pointed at Sol. Axions generated in the
solar plasma are expected to convert to x-rays after entering the magnetic field via the
Primakov effect. X-ray detectors are located at either end of the tube. This
experiment has been conducted using vacuum, helium-4, and helium-3 inside the
magnet bore in order to scan different energy ranges for the proposed axion.

18. ADMX, located at the University of Washington’s Center
for Experimental Nuclear Physics and Astrophysics, uses an
eight tesla magnetic field in a resonant microwave cavity to
detect axions decays via the Primakov effect. The apparatus
is supercooled with liquid helium to a temperature of 4.2
degrees Kelvin. The resonant frequency of the chamber is
changed by adjusting the position of the tuning rods. Axion
decays are detected with superconducting quantum
interference devices (SQUIDs).

19. WIMP detection experiment results as of July 2012.

20. Axion detection experimental results as of March 12, 2012.

21. Timothy J. Sumner, "Experimental Searches for Dark Matter", Living Rev. Relativity 5,
(2002), http://www.livingreviews.org/lrr-2002-4 (November 29, 2012)
“IceCube in Depth”, IceCube Neutrino Observatory,
http://icecube.wisc.edu/science/depth (November 29, 2012)
Icecube Neutrino Observatory images courtesy of the National Science Foundation.
Thierry Stolarczyk, “Overview of the ANTARES experiment”, ANTARES home page,
http://antares.in2p3.fr/index.html (November 29, 2012)
ANTARES module image property of Camille Moirenc for the ANTARES collaboration.
ANTARES computer model property of F. Montanet, the French National Center for
Scientific Research, and the University of Joseph Fourier.
Yusuke Koshio, “Details of Super-Kamiokande”, Super-Kamiokande Official Homepage,
http://www-sk.icrr.u-tokyo.ac.jp/sk/detector/detail-e.html (November 29, 2012)
Kamiokande detector graphics property of Kamioka Observatory, University of Tokyo.
Lynne Jenner, “Fermi Spacecraft and Instruments”, Fermi Gamma-ray Space Telescope,
http://www.nasa.gov/mission_pages/GLAST/spacecraft/index.html (November 29, 2012)
Fermi space telescope images courtesy of NASA and Stanford University.

22. Picasso render property of Alex Pepin and Martin Auger.
“Detector Concept”, The Picasso Experiment,
http://www.picassoexperiment.ca/experiment.php (November 30, 2012)
DEAP-3600 schematic courtesy of DEAP Project, Queen’s University at Kingston.
“Liquid argon based Dark Matter detection”, The DEAP Experiment,
http://deap.phy.queensu.ca/ (November 30, 2012)
Aprile, E., et al. (2010, May 3). First dark matter results from the XENON100 experiment.
Physical Review Letters , 105:131302. Retrieved December 1, 2012, from the arXiv
datadase.
XENON detector image courtesy of the University of Zurich.
XENON schematic property of Alan Stonebraker.
DRIFT II graphics courtesy of the U.K. Dark Matter Collaboration.
“DRIFT (Directional Recoil Identification From Tracks)”, Sheffield Particle Physics: Dark
Matter, http://drift.group.shef.ac.uk/ (December 1, 2012)
“The Experiment”, CAST – CERN Axion Solar Telescope,
http://cast.web.cern.ch/CAST/CAST.php (December 1, 2012)

23. “Experiment”, ADMX | Axion Dark Matter eXperiment,
http://www.phys.washington.edu/groups/admx/experiment.html (December 1, 2012)
ADMX images courtesy of the ADMX Collaboration and CENPA.
“The Experiment”, Super Cryogenic Dark Matter Search
http://cdms.berkeley.edu/experiment.html (December 1, 2012)
CDMS II apparatus photos courtesy of the SuperCDMS Collaboration.
MINOS mural photo courtesy of flickr member WMGoBuffs.
Aprile, E., et al. (Nov. 2, 2012). Dark Matter Results from 225 Live Days of
XENON100 Data. Physical Review Letters, Phys. Rev. Lett. 109, 181301. Retrieved
December 1, 2012, from the arXiv datadase.
J. Beringer et al. (Revised March 12, 2012 by L.J. Rosenberg and G.G. Raffelt). Axions
and other similar particles. (Particle Data Group), PR D86, 010001 (2012).