SuperCDMS SNOLAB will be a next-generation experiment aimed at directly detecting low-mass ( \leq 10 \mathrm { GeV } / \mathrm { c } ^ { 2 } ) particles that may constitute dark matter by using cryogenic detectors of two types ( HV and iZIP ) and two target materials ( germanium and silicon ) .
The experiment is being designed with an initial sensitivity to nuclear recoil cross sections \sim 1 \times 10 ^ { -43 } \mathrm { cm } ^ { 2 } for a dark matter particle mass of 1 \mathrm { GeV } / \mathrm { c } ^ { 2 } , and with capacity to continue exploration to both smaller masses and better sensitivities .
The phonon sensitivity of the HV detectors will be sufficient to detect nuclear recoils from sub-GeV dark matter .
A detailed calibration of the detector response to low energy recoils will be needed to optimize running conditions of the HV detectors and to interpret their data for dark matter searches .
Low-activity shielding , and the depth of SNOLAB , will reduce most backgrounds , but cosmogenically produced ^ { 3 } H and naturally occurring ^ { 32 } Si will be present in the detectors at some level .
Even if these backgrounds are \times 10 higher than expected , the science reach of the HV detectors would be over three orders of magnitude beyond current results for a dark matter mass of 1 \mathrm { GeV } / \mathrm { c } ^ { 2 } .
The iZIP detectors are relatively insensitive to variations in detector response and backgrounds , and will provide better sensitivity for dark matter particle masses ( \geq 5 \mathrm { GeV } / \mathrm { c } ^ { 2 } ) .
The mix of detector types ( HV and iZIP ) , and targets ( germanium and silicon ) , planned for the experiment , as well as flexibility in how the detectors are operated , will allow us to maximize the low-mass reach , and understand the backgrounds that the experiment will encounter .
Upgrades to the experiment , perhaps with a variety of ultra-low-background cryogenic detectors , will extend dark matter sensitivity down to the “ neutrino floor ” , where coherent scatters of solar neutrinos become a limiting background .