Stage Seven [More Chillin', Of MIRI Detector] -- On The Next Gen 'Scope, Well Underway Tonight...

This will be a neat trick of thermal engineering, all the way out at L2: the detector of the mid-range infrared wavelengths must be chilled. . . to a very, very cold state, or else it will see only its own residual heat, due to how red shifted these photons / stretched wavelengths are. So, super cooled gases will be sent through a pinch point, and then sprayed out into the a larger enclosed container, in a process somewhat like a water vapor mister, cooling everyone around the halo of mist -- at the Disney (or Universal) amusement parks, on a hot day.

This trick will, it is hoped, let the MIRI cool to EIGHTEEN TIMES colder than your freezer at home, or below seven kelvins. Very near absolute zero. And it will take a few weeks yet, of this "wicking" -- but if all goes as planned, we will be ready for science by later in May or early June. Here is the latest:

. . .“The Mid-Infrared Instrument (MIRI) and other [Next Gen 'scope] instruments have been cooling by radiating their thermal energy into the dark of space for the bulk of the last three months. The near-infrared instruments will operate at about 34 to 39 kelvins, cooling passively. But MIRI’s detectors will need to get a lot colder still, to be able to detect longer wavelength photons. This is where the MIRI cryocooler comes in. . . .

“Why so cold? MIRI’s state-of-the-art light sensitive detectors that are tuned to work in the mid-infrared are blind unless they are cooled below 7 kelvins (-266 degrees Celsius, or -447 degrees Fahrenheit). For contrast, a standard domestic freezer cools its contents to about 255 kelvins (-18 degrees Celsius, or -0.7 degrees Fahrenheit). At higher temperatures, any signal that may be detected from the sky is lost beneath the signal from its own internally generated ‘dark current.’ Even if the detectors are cooled, Webb images would still be swamped by the glow of thermal infrared light emitted by MIRI’s own mirrors and aluminum structure if they are to get warmer than 15 kelvins (-258 degrees Celsius, or -433 degrees Fahrenheit). . . .

If you compared it on the Fahrenheit scale, your freezer would only be about one-four-hundreths as cold as the MIRI detector, when fully cooled to around 7 kelvins.

As it snows here, again. . . that's. . . some CRAZY hard frozen ice cream sammy! Smiling. . . . be excellent to one another.

नमस्ते