Minutes of the Oct 5, 2007 Tevatron Dept Meeting http://indico.fnal.gov/conferenceDisplay.py?confId=1294 * Shutdown Status (Ron for Jim Volk) - After repairing an outside air leak following replacement of the E19 spool and E19-2 dipole, E1 was hipotted successfully; TD personnel can now begin retrofitting the spool package conning towers in that house. The A14-2 dipole was found to have an electrical fault when A1 was hipotted following vacuum leak repairs; the dipole is being replaced. No vacuum leak was found in A2 - that house is considered OK for cooldown. Proton injection kicker F17K5 was replaced successfully. The D0 low-beta quad adjustments are complete. There has been some difficulty adjusting the CDF low-beta quads, but all now seems OK; there will be discussions on how to correct the recent problems. * Configuring the C0 Shunt with C49 (Ron) - Since EE Support commissioned the C0 shunt (for the 4 MI dipoles used at C0) several years ago, we have relied on save/restores to reload the T:C0SH ramp card with the appropriate entries. Now the C49 application will be able to reload the card just like the other ramp cards. A new sequence, group, and ramp were created just for that card. Another benefit is that the card entries can be modified, if needed, within C49. * Implementing the New Collision Helix (Alex Valishev) - Alex investigated two options for getting the collisions with the new short arc horizontal collision helix. First, using an "injection" helix all the way through the squeeze causes the beams to have a larger offset through the low-beta triplets - not good since we are already concerned with aperture now. Also, there is still much uncertainty about initiating collisions in this scenario. The second option is to flip to vertical short arc collision helix too, which would allow us to use separator 2-bumps, like now, for initiating collisions. However, that would require using a vertically-flipped injection helix also. Alex's model suggests rather small feeddown changes would be needed for the new injection helix. In the end, the squeeze would look similar to the existing one - transitioning from the injection to the collision helix in the middle of the squeeze, but without any separator polarity changes. The collision would remain the same in the long arc, but would be flipped in the short arc horizontally and vertically. We will pursue the second option. One question yet to be resolved - how does the vertically-flipped injection helix affect pbar injection?