# Presentation: 191225

## Main Injector Operation Status

- Recent Developments in MI
- Main Injector Current Performance
- Pbar production, Proton for Collider, Pbar for Collider
- Run II Plan Project Update
- Other Efforts

- David Johnson
- Main Injector/Recycler Department

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Main Injector Recent Developments

- Lattice Match between Injection lines(MI8) and Main Injector
- Beam Loading compensation and tune up of the proton coalescing for Collider program
- Multi batch Beam Loading compensation and tune up of the pbar coalescing for the Collider program
- Studies to understand the longitudinal emittance growth in the Main Injector and R&D its solution
- Bunch-by Bunch Damper studies
- Studies to understand an apparent vertical emittance growth between 8 and 150 Gev
- Slip stacking studies
- 2.5 Mhz Acceleration studies
- Development of Recycler pbar extraction and acceleration/coalescing in MI

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Main Injector Current Performance

- Pbar Production
- Proton Performance
- Pbars from Accumulator
- Pbars from Recycler

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Pbar Production Cycles

- Run II Goal:  5E12/pulse @ 1.5 sec. cycle time

- >4.25E12 @ cycle time > 2 sec
-   depending on stack size

_**Current status**_:

- Intensity on target (E12)

- (Nov 1 – Jan 13)

- 1.46 sec cycle time

- 4.5E12

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Pbar Production Cycles: Transverse

- 120 GeV

- 8.9 GeV

- Transverse emittance growth between 8 and 120 GeV:
-    Horizontal: 16  -> 20          Vertical: 16  -> 22 *

- *Instrumental issues  (suspect FW PMT)

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## MI Proton Performance: Goals

- Parameter              Goals (Run II)        Current Performance

- Protons/bunch
- Coalescing eff.
- Transverse emittance
- (95% normalized)
- Longitudinal emittance
- (95% normalized)

-  270E9  at Collision        >300E9  (7 bunch)
- ~300E9 at 150 MI *        250E9  (5 bunch)

- 90%                            85% (7 bunch)
- 			92% (5 bunch)

- 20 -mm-mr at collision    19 -mm-mr Horizontal
- 18 -mm-mr at 150 MI     22 -mm-mr Vertical

- 2.0 eV-sec at collision     2.8-3.2 eV-sec (7 bunch)
- 	                        2.2-2.6 eV-sec (5 bunch)

- *Assume 90% eff. to collision

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Proton Performance: Transverse 

-  Horizontal data not corrected for non-zero dispersion
-  We need to understand apparent vertical plane emittance growth and minimize it.

- Oct 15

- Nov 1

- Dec 1

- Jan 1

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Proton Performance: Coalescing

- 7 bunch ~ 85% efficiency (3% satellite , 12% DC beam), 310E9
- 5 bunch ~ 92% efficiency (1% satellite, 8% DC beam),    245E9

-  Coalesced bunch long emit. Vary from
-     ~3.2 eV-sec (SBD,rms)   7 bunch
-     ~2.2 eV-sec (SBD, rms)  5 bunch
-     *{2.9-4.0 eV-sec (gaussian fit to *
*                            **compare with Tev}*

-  Gain of Booster Quad damper reduced
- to allow longitudinal emittance of Booster
- bunches to grow from .15 eV-sec to about
- .3 eV-sec to reduce long emit blow up in
- Main Injector (see longitudinal damper)

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Proton Performance: Longitudinal

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## MI Pbar Performance: Goals

- Parameter               Goals (Run II)   MI Current Performance

- Pbars/bunch
- Coalescing eff.
- Acc -> 150 GeV
- Transverse emittance
- (95% normalized)
- Longitudinal emittance
- (95% normalized)

-   31 E9  at Collision **            22 – 35 E9
- ~33 E9 at 150 MI *      (depending on stack size)

- 90%  transmission      85 - 90% coalescing eff
- 		         80 - 90% transmission

- 15 -mm-mr at collision   <14 -mm-mr Horizontal
- 14 -mm-mr at 150 MI    <12-mm-mr Vertical

- 2 eV-sec  collision                 2.8-3.2 eV-sec

- *Assume 90% eff. to collision

- **FY03

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Pbar Performance: Transverse emittance

- 11/1

- 12/1

- 1/1

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Pbar Performance: Coalescing

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Pbars from Accumulator:Beam Loading Compensation

- BLC off

- BLC on

- Mountain Range plot of 4 pbar 2.5 Mhz batches each
- with 7-9 53 Mhz bunches through the coalescing process

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Pbars from Accumulator:Beam Loading Compensation

**BLC on**

**BLC off**

- Average Longitudinal emittance coalesced pbar bunches ~ 2.7 eV-sec

- No dependence on position of bunch in train observed

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Pbars from Accumulator:  Coalescing Efficiencies 

- Efficiency vs Pbars Unstacked

- Pbar coalescing efficiency _with_ Feed Forward Beam Loading
- Compensation is ~ 85% independent of stack size (efficiency
- At large stacks increased by 10-12% with implementation

- BLC off

- BLC on

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Pbars from Recycler

** ****Early stages of development**
-  Synchronous transfer in 2.5 Mhz bucket
-  De-bunch and adiabatically capture in 53 Mhz
-  Accelerate in 53 Mhz buckets
-  Coalesce in 2.5 Mhz bucket for   transfer to Tevatron

** ****Last three steps will be eliminated with 2.5 Mhz acceleration to 27 GeV and rotated into 53 Mhz bunches**

- Tev inj.

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## MI Lattice:  Match 8.9 Gev line to Ring

- Horizontal

- Vertical

- Proton beam sigma in 8 Gev Line and MI _before_ matching

- MI

- 8 GeV

- Ming-Jen Yang

-  sigma error

-  [mm]

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## MI Lattice: Match 8.9  Gev line to Ring

- Horizontal

- Vertical

- Proton beam sigma in 8 Gev Line and MI _after_ matching

- Ming-Jen Yang

-  sigma error

-  [mm]

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## MI Lattice: Match 8.9 Gev line to Ring

- Before Injection match

- After Injection match

- Comparison of first turn MI lattice functions for measured and design

- Ming-Jen Yang

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## MI Lattice: 8 GeV Circulating Lattice

- Ming-Jen Yang

- Horizontal Plane

- Vertical Plane

- Beta function [m] at BPM

**design**

**measured**

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## MI Lattice: 150 GeV Lattice

- Ming-Jen Yang

- Horizontal Plane

- Vertical Plane

- Data taken on Tevatron injection orbit (p/p ~.0036)

- Beta function [m] at BPM

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## MI Lattice: 150 GeV Dispersion

- Measured and calculated Horizontal
- And Vertical Dispersion

- HP106 vs dp/p

- Ming-Jen Yang

- D

- D**y**

- D**x**

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Run II Plan Projects

- Longitudinal Emittance Growth (Dave Wildman)
- Commissioning of 53 Mhz beam loading compensation for pbar coalescing (Joe Dey)
- 53 Mhz beam loading compensation on ramp (Joe Dey )
- Dampers in the MI (Bill Foster)
- BPM Upgrade in MI (Brajesh Choudhary)
- 2.5 Mhz Acceleration (Chandra Bhat)
- General Diagnostics Improvement (Dave Capista)
- Tune Meter for pbar operation (Denton Morris)
- Improvements in MI ramp and closure programs (Bruce Brown)
- Tune and chromaticity calculator program (Guan Wu)

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## WBS1.2.1 Longitudinal emittance growth

- _Injection_
- Coupled-bunch motion (modes 16 & 36) observed on first turn in MI
- Solution: 1 Check all existing passive dampers in Booster
-                  2 Increase gain on mode 36 active damper
-                  3 Build active damper for mode 16
- Status: This is on going Booster effort. There are currently no plans for a more 16 active damper.
- Residual coupled bunch motion from the Booster drives to the MIRF cavity modes at 128 Mhz and 224 MHz
- Solution: Build a bunch by bunch longitudinal damper in MI
- Status: Parts on order see WBS 1.2.4

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## WBS 1.2.1 Longitudinal emittance growth

- _Transition_
- There is a 10 degree phase error on the $29 cycles crossing transition with heavy transient beam loading which results in dipole oscillations that persist throughout cycle
- Solution: The present high level transient feed-forward BLC system can reduce this phase error by X3. The system needs to be modified to operate throughout the cycle.
- Status:  to be commissioned March ’03  See WBS.1.2.3
- _Flattop_
- The excitation of the MIRF cavity mode at 224 Mhz is observed to grow throughout the cycle
- Solution: The new bunch by bunch damper should effectively damp these coupled bunch oscillations
- Status: Parts on order  see WBS 1.2.4

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## WBS 1.2.2 Beam loading compensation

- Current system provides compensation during pbar coalescing at 150 GeV.
- System now fully commissioned
- System has been stable for at least the last two months

- Green trace ON
- Blue trace OFF

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## WBS 1.2.3 Beam loading compensation on Ramp

- Provide feed forward beam loading compensation on all cycles from injection through flattop.
- Will utilize 465 ramp which will track the MI energy
- Status:
- Hardware installed over Jan ’03 shutdown
- Need commissioning and study time
- Implemented March ’03

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## WBS 1.2.4 Dampers in the MI

- All MI dampers controlled by a single commercial digital filter card with a large FPGA.
- Longitudinal
- Remove coupled-bunch oscillations in beam delivered from Booster
- Prevent growth of coupled-bunch instabilities
- Allow bunch rotation to be effective on stacking cycles
- Increase coalescing efficiency and reduce momentum spread after coalescing
- Transverse
- Reduce emittance growth from injection steering errors (p and pbar)
- Reduce any residual emittance growth during ramp
- Permit MI operation at increased intensity in NuMI era

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## All-Coordinate Damper w/ Echotek Card

- 53 MHz, TCLK, MDAT,...

- Monster
- FPGA(s)

- Minimal
- Analog
- Filter

- FAST
- ADC

- Stripline
- Pickup

- Minimal
- Analog
- Filter

- FAST
- ADC

- 14

- VME

- 106 / 212 MHz

- Stripline
- Kicker

- Power
- Amp

- Minimal
- Analog
- Filter

- FAST
- ADC

- Resistive Wall Monitor

- Broadband Cavity

- FAST
- DACs

- > 27 MHz

- FAST
- DACs

- Power
- Amp

- Transverse
- Dampers
- Identical
- X & Y

- Longi-
- tudinal
- (Z)
- Damper

- 2-10

- 2-10

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## WBS 1.2.4 Dampers in the MI: Status

- Transverse
- Demonstrated bunch by bunch damping in MI (next slide)
- No new high level (used existing damper pickup and kicker)
- Proof of principal demonstrated using three turn filter
- A lot of software and cycle control is needed to become operational
- Operational May ‘03
- Longitudinal
- Parts for 3 wide band cavities ordered (June delivery for ferrite)
- Power amplifiers have been ordered (May delivery)
- A 1/3 power test (using spare Recycler PA and existing wide band cavity is planned for Feb – March ’03
- Cavities (and PA’s) to be installed summer ’03

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## WBS 1.2.4 Dampers in the MI:

***...******CAN ALSO ANTI-DAMP TO ***
***BLOW ANY SELECTED BUNCHES ***
***OUT OF THE MACHINE***
********* ******Anti-Satellite Device***

- Damping kick shared
-  for Bunches #41 - #51

-  Pickup Signal from Bunch #43

-   Ashmanskas, Foster,Wildman, Schappert, Crisp, Nicklaus

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## WBS 1.2.6  2.5 Mhz Acceleration

- _The Scheme__:_

- Four pbar bunches ( L ~ 0.5 to 1.5 eV-s)
-   transferred in 2.5 Mhz bunches
- Accelerate slowly to 27 GeV
- Bunch rotated in 2.5 Mhz bucket
- Captured in 53 Mhz bucket
- Accelerated to 150 GeV

- Goal:  To provide low longitudinal emittance (2 eV-sec or less) pbars
- for Collider

- _Initial Tests_:

-  Inject 7 bunches 53 Mhz from Booster
-  Accelerate to 27 GeV and de-bunch
-  Capture in 2.5 Mhz bucket and rotate
-  Capture in 53 Mhz bucket, accelerate to 150 Gev

- 2.1

- 2.6

- .15

- .3

- ev-sec

- Bhat, Wu

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## WBS 1.2.6   2.5 Mhz Acceleration

- _Current Issues_ (requires tuning and optimization)

- Observe significant long emittance growth
- during 8 to 27 GeV acceleration in 53 Mhz
- 2.5 Mhz phase stability
- Beam loading compensation tuning

- A 2.5 Mhz RF phase and radial feedback
- system is being constructed
- A 2.5 Mhz RF transition phase jump system
- is being constructed

- _Work in Progress_

- _Schedule_: March 2003 initial tests with pbars
- 	       Summer 2003 commissioned for pbars

- Bhat, Wu, Chase

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Other Efforts/Projects

- Slip Stacking
- Procedure is working at low intensities
- Feed back and feed forward BLC development is underway
- Bunch compression
- Demonstrated in Recycler with wide band cavities
- Attempted in MI, but need new cavities
- Lattice characterization
- Continued refinement of MI lattice at 8.9,120, and 150 GeV
- Operational Improvements (shot set up, etc)
- Instrumentation Improvements
- NuMI support
- SY120 Support

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Slip stacking

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Slip stacking

- K. Koba

- 1 Booster turn (.4E12/batch)

- 4 Booster turn (1.8E12/batch)

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Slip stacking

- Status
- Working with low intensity (.75E12 ppp)
- No beam loss during process
- Long. Emittance growth ~100% and due to LLRF timing jitter (should be 60% by ESME simulation)
- LLRF problem fixed during this shutdown
- Beam loading effects at high intensity
- Working on BLC with feedback and feedforward

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Bunch compression

- Alternate scheme for generating high intensity batches
-   for stacking
- Initial test performed in Recycler using wide band cavities
-   and modulating RF voltage between barrier buckets
-  (see next slide)
- Test performed in MI using a spare Recycler PA and a
-   ferrite loaded broad band cavity in MI
- Need higher voltages -> use new wide band cavities to
-   be installed summer ‘03

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Batch Shrinking Test

**Injected**
**Batch**
**From**
**Main**
**Injector**

**Half-Length**
**Batch**
**Extracted **
**Back to**
**Main**
**Injector**

***10 msec / trace***

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Bunch Compression

- Inject 84 bunches into MI barrier bucket to test fast bunch compression in MI

- Barrier bucket height ~500V

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Summary

-  MI8 line and Main Injector lattice has been matched. Beta and dispersion is matched to better than a few %. Lattice measurements at 150 GeV show 10-20% discrepancy... need further investigation.
-  There are some lattice issue at 150 GeV between MI transfer lines and the Tevatron.
-  Proton emittance growth during acceleration is an issue we are investigating. The coalescing efficiency is about 85%.
-  Antiproton beam from AccumulatorMITeV also has less than 2 pi mm-mr emittance growth. The longitudinal emittance growth is as expected.
-  The antiproton coalescing efficiency is co-related with the pbar longitudinal emittance. For small emittances MI has achieved 95% coalescing efficiency. On average the coalescing efficiency is about 85%.
-  Beam loading compensation has been implemented for protons and pbars. This has improved coalescing performance 10-15 %.
-  An R&D effort with beam studies for slip stacking process is underway.
-  An R&D effort and beam studies for 2.5 MHz acceleration of pbar is also in progress.
- MI Transverse Damper proof  of principal -> operational May ’03 time frame
- MI Longitudinal damper 1/3 power test this spring with full capability after summer shutdown
- Pbars from Recycler have been accelerated and injected into Tevatron

- Accelerator Advisory Committee February 4-6,2003

- David Johnson

## Summary   (The bottom line)

- Preservation of Longitudinal and Transverse emittance  of both Protons and Pbars
-                 -> Dampers
- Feedforward Beam Loading on ramp
- 		      -> in progress
- Increase proton intensity
-                -> slip stacking, bunch compression, dampers
- Reduce longitudinal emittance of pbars (and protons?)
-                 -> 2.5 Mhz acceleration
- Improve Lattice & Machine Operation
-                 -> improvements in instrumentation ( on going)
- Continued Machine studies

- Accelerator Advisory Committee February 4-6,2003

- David Johnson