# Presentation: 474499

## G0 Coordinator Update & “To-Do List”

- Joe Grames
- William & Mary, June 5-6, 2006

-  Hall C Beam Line Tasks
-  Accelerator Preparation Tasks
-  Beam Halo
-  Startup & Commissioning Tasks/Schedule

## Hall C Beam Line Tasks

-  Remove 3” beam pipe & pedestal & 2” beam pipe through HKS Q1
-  Remove halo girder & pedestal
- _Beam line installation for future G0 runs_
-  Secure & align beam pipe pedestal at pivot
-  Install & align 3” round beam pipe from pivot to halo girder w/ pedestals
-  Install & align halo pedestal & girder
-  Replace ion pumps 3H00G (pivot) and 3H00F (halo girder)

## Moller Polarimeter

-  Verify diagnostic on IPM3C16 (intermittent)
-  Align solenoid (mis-aligned when cold)
-  Repair bellows support bracket at 3C17A (aperture)

- Hall C Beam Line Tasks

## Accelerator Preparation Tasks

- EGG & CASA Related Items

- Summer Run
-  Halls A (1 uA) & C (60 uA & polarized) each at 362 MeV
-  Half-pass setup (injector + NL = 342 MeV & SL = 20 MeV)
- Polarized Source
-  Gun2 & superlattice photocathode (same as Spring 687 MeV run)
-  Photocathode will be reactivated to restore QE (polarization should not suffer)
-  Hall C fiber laser (same as Spring 687 MeV run)
-  Hall A will use 2nd fiber laser or a ‘tap’ of Hall C fiber laser
-  Pockels cell & laser table setup will need to be done by end of June
- Injector & Machine Optics
-  Possible re-allocation of ~2 MeV between injector & NL (TBD)
-  Injector/NL matching (scheduled for startup)
-  Quad field map implementation to improve AT/3C match (plan due 6/6)
-  Energy FFB to be used on Hall C
-  SL Phase Compensation Scheme (plan due 6/6)
-  Position FFB & Coil Modulation upgrade and integration

## Accelerator Preparation Tasks

- G0 Girder Diagnostics

- _Beam Profile Scans_
-  Move harp pre-amps closer to improve signal:noise ratio
-  Automate process for PMT-based scans
- _BPM Cavities_
-  Cavity-1 calibration complete
-  Cavity-2 calibration in ATLIS start-up plan

## Accelerator Preparation Tasks

- Software for Unbalanced Linacs

- Many software applications anticipate both linacs on (and equal).  Two databases maintain the beam energy.  Software group is preparing solutions to insure the 362 MeV setup is transparent to these codes.
- Art++ (model for energy)
-  AutoQuad
-  PZT
-  SmartKnobs
- MMS (run-time for energy)
-  LEM
-  DogLeg Calculator
-  MultiHarp Emittance
-  RF GradCalibration
-  Spreader/Recombiner Knobs
-  SmartKnobs
-  Spin Calculator (uses BEM as well)
- Other
-  Hall Rasters
-  BELS

- I’ll follow up on this...

## Accelerator Preparation Tasks

- FFB (Fast Feedback) Upgrade
- & Integration w/ Coil Modulation System

- The FFB system (BPM’s + correctors) is an orbit stabilization method aimed at drift and 60 Hz harmonic content up to ~720 Hz.
- The 362 MeV optics (one linac + AT extraction) rendered FFB system less effective.
- Plans are moving forward for long range upgrade with dynamically selected magnet set to meet arbitrary optics setup.
- Why does this involve G0?
-  Prefer minimal population of coils to install & maintain.
-  Integrate FFB & modulation to address same magnets.
- What does G0 gain (or not lose) ?
-  Same functionality.
-  Improved location and choice of modulation coils for response matrix.

## Beam Halo

- _Halo was characteristically bad for two periods._
- Vacuum Leak => occurred during early start-up...left some confusion & uncertainty.
- Machine Setup => about a week after commissioning period ended
- Setting the electron bunch length properly
- Fixing dispersion “leakage” into the Hall C line

- Achieved specified halo rates for remainder of the 687 MeV.
- The 362 MeV test run at the end of the 687 MeV run achieved specified halo rates without significant tuning.

## StartUp & Commissioning Schedule

- Week 1 ~ basic machine checkout & turn gun/injector on
- Week 2 ~ injector setup & parity checks, lock up Hall C & turn machine on
- Week 3 ~ 2-beam extraction, beam quality & parity to Hall C checks, start commissioning