Make radiation measurements

(the transitional task "Assistant" is also here, for convenience)
After his experience at Wild Territory, Kruglov refuses to make radiation measurements in the dangerous area, despite Sakharov begging him to do it. Sakharov wants you to assist him.
== Walkthrough ==
Talk to Kruglov to let him know you'll assist him.
Make your way through the tunnel under the road, wiping the zombies around so Kruglov doesn't have any issues. After he reaches the bus on the road, a sudden blowout happens, and Marked One loses consciousness, leading to another vision.
Wake up after the vision, talk to Kruglov and help him out. Make your way back to the bunker in the same manner. Watch Kruglov reporting to Sakharov. Wait for Sakharov to make some calculations, and speak to him to end the quest and receive the Adjusted psi-helmet that will protect you from the psi field around the Yantar factory.
== Notes ==
Adjusted psi-helmet is a quest item and can't be dropped from the inventory.
== Bugs ==
* The dialog cutscene in the bunker might get stuck sometimes, with Kruglov and Sakharov just standing there and not talking. Save and load the game if this happens to you.