# Presentation: 019335

## Bottom Line Numbers

- The proton source is currently delivering about a fifth of what MiniBooNE would like.
- Worrisome levels of activation in the Booster mean we will not push beyond this level without improvements in losses.
- Some limits have been lowered, at least in preparation for the January shutdown.
- Collimator shielding has been cancelled for the January shutdown.
- We’ll proceed as best we can without it.

## Activation in Booster

## Bad News: Booster Collimator Shielding Cancelled for January

- Radiation levels in the area of the collimators meant that it would require several crews to complete the shielding job.
- The awkwardness of location made it likely that the beam pipe or bellows would be damaged – particularly if we had multiple crews trying to work quickly.
- The existing design did not allow for servicing of the motors, LVDT’s, or *vacuum flanges* without **unacceptable  radiation exposure**.  Risk of significant downtime (weeks or more).
- Important “details” (e.g. cooling) had not been worked out.
- There was no provision for the eventual removal of the system.
- Conclusion: Remove collimators during January shutdown and do it right.

## Conceptual Design of Collimator

- Integrate collimator and enough shielding for at least twice present Booster flux at 1% high field scraping into a movable  system which can be assembled externally and installed quickly (~ 1 day)
- Design must include a clear plan to scale up to the full shielding (MiniBooNE+NuMI @ 2% scraping).
- After extended operation at full flux:
- There must be a reasonable method for servicing the motors and LVDT’s.
- There must be a reasonable plan to remove the central collimation system (“coffin”) in the event of a catastrophic failure (e.g. vacuum leak).
- There must be a reasonable plan to remove the entire system in the event Santa brings us a new Booster.

## Collimator Plan

- Peter Kasper will manage project.
- Design will be hashed out with full participation of Gerardi and Mokhov.
- Goal: converge on a plan of action by Jan 21st.

## Good News on Personnel Front

- Chuck Ankenbrandt has joined group as “Beam Physics Liaison”, charged with prioritizing studies.
- Xi Yang (postdoc) will soon join group, primarily working on non-invasive profile measurement.  Will also directly assist Chuck.
- Xiaobiao Huang (graduate student) will come up from Indiana to work on precision lattice measurement and study mechanisms of beam loss from space charge.
- Linda Coney (postdoc) has begun to contribute significant time.  Primarily working on beam steering and (soon) lattice measurement.
- We have (we hope) identified a person for the low level RF Engineering position.

## Developments on Studies/Modeling Front

- Completed calibration of IPM (ionization profile monitor).
- Used DC beam time to measure emittance growth at injection – to be used to compare to models.
- Space charge group has begun to focus on Booster again. Charges:
- Determine mechanism of space charge related beam loss.
- Identify likely important components of Booster model
- Alignment error.
- Multipole contributions.
- Aperiodicity (leads to extra harmonic instabilities)
- Estimate effect of large aperture RF cavities.

## RF Upgrade Project

- Vacuum prototype proceeding; still plan to have ready for the summer shutdown.
- When design is complete, it is planned to have universities machine the components for a second prototype.
- Example plans have gone out to get an idea which machine shops are capable of machining the necessary parts.

## Plan

- Collimator delay is a major blow; it was hoped that we would be entirely done with hardware projects for the near future.
- The booster will be back up the last week of the shutdown.  This will allow several days of dedicated studies:
- Optimize steering correction.
- Test Gamma-t jump.
- DC space charge studies
- ??
- Proceed with collimator design and do the best we can do.