MPS Recover

Common Issues

Cavity Wobbles and Trips

First we need to check if the cavity has actually tripped. Consult either the SRF Turn On/Off page or the RF Main Page. Below are 4 examples of possible states for each cavity:

This one is totally off, if this happens unexpectedly then call SRF

This one just has the RF tripped off, we'll talk more about this one in a bit

This one is a wobbled cavity, skip ahead to “Wobbles cont.”

This is a perfectly on and functioning cavity

If the RF has tripped, go to RF Main if you're not there already, then click “Details” on the issue cavity as shown below

Now consult the following image to see if the issue with the cavity can be reset without consulting SRF, the image shows a situation where we've tripped on “Excessive Forward Power”, very common. Because it's not in a red box we can continue on, if instead we had tripped on “Excessive Cavity Field” for example, we should contact SRF.

If it's a resettable issue, follow the following image

On occasion, the cavity will quickly trip again, if you click details and find that it tripped on “Cavity Field Low” then it's a common issue. Some cavities throw off a lot of X-Rays that can interfere with the abilities of neighboring cavities to ramp up. Here's what to do:

First reset the problem cavity

Press “Disable” (next to the “Start” button we used earlier) on both of the cavities above and below the problem cavity

Click “Start” for all three of them quickly

if this happens again, then include an additional cavity above and below for a total of 5, it really shouldn't ever extend outside of the cryomodule, but cavities like D1372 often require turning off and on all of the cavities in the cryomodule.

Wobbles Cont.: Welcome back! For instances where the cavity merely wobbled, you can reset them from RF Main or MPS Operator as shown in the pictures below, then you should be good to send beam again!

MTCA 06

Diagnosing

Other Issues