Detecting dark matter

Where is dark matter ?

Since dark matter is found in young and old galaxies, we know a few things about the particles that comprise it.  

  1. Dark matter must not be fast enough to escape.  That sets a limit on its velocity of about 1/1000th the speed of light.  
  2. Dark matter should fit in a galaxy.  This puts a constraint that its wavelength should not be bigger than a galaxy. 
  3. Based on how fast stars the Milky Way move, we can estimate the density of dark matter where we are.  The density is equivalent to a mass of 1/3 of a proton per cubic centimeter.  

For instance, if dark matter had a mass the same as a proton, about a million dark matter particles would stream through a liter of water per second.  But don't worry, we still have never observed any interaction between dark matter and matter ! (But we hope to !)

 

DAMIC (Dark Matter in CCDs)

If dark matter is steaming through the earth, we need a very sensitive detector to measure its interactions. 

The DAMIC experiment is designed to detect several potential types of dark matter spanning more than 7 orders of magnitude in mass.

  • It can detect the weak interactions of dark matter.
  • It can detect the electromagnetic interactions of hidden dark matter. 
DAMIC experiment

 

DAMIC status

  • DAMIC@SNOLAB has been running in Canada, 2 km underground in a mine, since 2014, and produced a number of interesting results. 
  • We are currently designing a new phase of DAMIC, called DAMIC-M, at Modane Laboratory in France, inside a mountain. DAMIC-M should be partially operational in 2020, and fully operational in 2024.

DAMIC-M

DAMIC-M will probe, for the first time, several classes of predicted dark matter that have specific rates and masses.

What's so good about DAMIC-M ?

  1.  We will probe energies 10 times smaller than DAMIC@SNOLAB, using a new, demonstrated CCD technology, called skipper CCDs.  We have some of these in the lab and our testing them now.
  2. The backgrounds in the detector will be 50 times smaller, meaning that we can detect a much smaller rate dark matter signal. This lower background comes from more careful production and handling of detectors and shielding. 
  3. The total mass of the detector will be 10 times more massive than the previous detector.  The CCDs will be the biggest ever produced, each with an area of 9 x 9 cmand a thickness of 675 um, and consisting of 36 million pixels.  

More information about DAMIC-M.