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Ali CMB Polarization Telescope (AliCPT)

Blocky building sits on dirt hill with snowy mountain and blue sky in background.
Ali CMB Polarization Telescope (AliCPT)
Credit: Yong-Ping Li

Telescope Details


Tibet, China


To probe the primordial gravitational waves originated from the very early universe and measure cosmic microwave background (CMB) polarization in the search for signals that would confirm the theory of inflation. CMB polarization measurements may provide for the first time a quantum probe of gravity.

NIST’s role:

NIST is leading many aspects of camera development, including the design, fabrication and characterization of superconducting detector arrays and electronics.

Significant discoveries:

This telescope is still under construction.

Other interesting facts:

AliCPT is the only CMB imager to be located in the northern hemisphere, which will allow the telescope access to map new regions of the sky to great depths. This will be important in checking other telescopes’ measurements because signals need to be detected in multiple parts of the sky to be confirmed.

Supported by:

Chinese Academy of Sciences 

Operated by:

An international collaboration led by the Institute of High Energy Physics, with about 100 scientists from China, the United States and Europe.


Light-colored rectangle on black stripe with white above and pink beneath.
Single NIST sensor
Credit: NIST
Six-sided bronze-colored plate lies on a metal surface.
Feedhorn array in stack of gold-plated silicon wafers that directs incoming light to sensors
Credit: NIST
Created September 30, 2021, Updated November 3, 2021