When opening LNL4 target jar, the valve did not sound as if air was entering it: we suspect the target was actually not properly under vacuum.

We mounted LNL4 target. However, we could not start the measurement because of bad vacuum. Cold trap was warm. We did several N2 washings to get rid of any residual humidity in the beam line.

We had to dismount the target and do several tests with the leak finder before finding out that the problem was a broken O-ring between target and target holder AND damaged chiller's tube valve on target holder.

As a consequence, the target was exposed to air for quite some time. No visible degradation. Some pictures are attached.

We finally started the scan: details in the excel sheet. Target seems to have withstood air humidity!