Beam ran well overnight. Last evening Vacuum Group diagnosed and repaired a catastrophic leak in the ILT cross region. You can see in the attached plot how venting that section caused elevated pressures in IOS, most likely due to the direction in which IOS:IV7 is installed. Most often it is the IOS section that is vented, and the neighbouring sections remain at high vacuum. So this gate valve would be installed looking downstream so that venting on the upstream side would tend to close the valve even harder. Yesterday was one of those rare times when the pressures were reversed, leaving only the spring tension of the valve maintaining vacuum in IOS. Pretty good, actually.

We are delivering a beam intensity exceeding the agreed rate. Intensity dropped off a little overnight, and it is pretty evident that it correlates with a higher vacuum in MCIS, suggesting that the 17O2 source gas flow has also dropped off. There is ample headroom presently, but the users may request a tweak after the energy change (in progress circa 09:00) and checks are complete.

Later... ICR requested a source tweak, which we did. A little increase.