# Presentation: 681017

## Overview of Current Performance and Plan for FY03

**FNAL**
**2/4/03 AAC Review**

**Overview of Current Performance and Plan for FY03**

## Accelerator Complex

- Overview for FY03

- 02/4/03

## Operating Scenario

_**Antiproton Production:**_**  Every ~2.2 seconds a single ****batch ****of 84 proton ****bunches ****is extracted from the Booster and accelerated from 8 GeV to 120 GeV in the Main Injector.  This beam is then extracted and targeted on the Antiproton Production Target.  8 GeV antiprotons from the target are collected and cooled in the Debuncher and then stored in the Accumulator ****stack.  ****Antiproton production takes place continually during Collider ****stores****.**
_**A Collider **__**shot**_** is the process of loading protons and antiprotons into the Tevatron for a ****store****.  A batch of 7 proton bunches is injected into the Main Injector and accelerated to 150 GeV.  These 7 bunches are then ****coalesced**** into a single bunch and injected into the Tevatron.  This is repeated 36 times.  The ****helix**** is opened in the Tevatron so that the protons and antiprotons circulate on separate orbits and do not collide.  Then 4 batches of ~5-10 bunches of antiprotons is extracted from the Accumulator stack and injected into the Main Injector.  These are accelerated to 150 GeV, ****coalesced**** into 4 bunches separated by 396 nsec, and then injected into the Tevatron.  This process is repeated 9 times.  When all 36 proton and 36 antiproton bunches are loaded into the Tevatron, the beam is accelerated to 980 GeV, and the ****low beta squeeze**** is initiated.  In the ****low beta squeeze**** quadrupole currents and the helical orbits are changed so that the transverse beam size is reduced at the Interaction Regions (****D0 and B0****) and the protons and antiprotons are brought into collision there.  A typical store lasts ~18 hours.**

- Overview for FY03

- 02/4/03

## Integrated Luminosity History

- Overview for FY03

- 02/4/03

## Peak Intensity History

- Overview for FY03

- 02/4/03

## Weekly Performance

- Overview for FY03

- 02/4/03

## Status on Luminosity Parameters

** **

- Overview for FY03

- 02/4/03

## Intensity

**• ****Booster can produce adequate # protons for Tevatron FY03 intensity goals**
**• ****Accumulator can produce (almost) adequate # antiprotons for FY03 goals**
**• ****Emittance growth produces poor efficiencies**

- Overview for FY03

- 02/4/03

## Emittance (1)

**•  **_**Caveat:**_**  There are uncertainties in following numbers due to instrumentation errors and uncertainties in deducing phase space quantities from measured quantities.**
**•  ****Proton longitudinal emittance:**
**	****- Booster can produce <.15 eV-sec bunches at required intensity (5 dipole mode ****	****	****	****dampers are effective in controlling coupled bunch instabilities)**
**	****- **_**However**_**, to control longitudinal instability in the MI the Booster emittance is ****	****	****intentionally blown up to ~.3 eV-sec/bunch (7 bunches)**
**	****- After coalescing in the MI this is ~3.5 eV-sec (this is what Tevatron sees @ 150 ****	****	****GeV)**
**	****- RMS bunch length at low beta is ~2 nsec (~4 eV-sec)**

- Overview for FY03

- 02/4/03

## Emittance (2)

**•  ****Antiproton longitudinal emittance:**
**	****- Accumulator core is kept at 25 eV-sec during shots, independent of stack size.  This ****	****	****	****allows for extracting 90% of the core with ...**
**	****- extracted emittance of .8 eV-sec – 2.5 eV-sec /bunch with an average of ~1.25 eV-sec**
**	****- MI measures ~1.5 eV-sec before coalescing, ~3.0 eV-sec after coalescing**
**	****- Tev measures ~3.5 eV-sec @ 150 GeV, ~3.5 – 4 eV-sec at low beta**
**•  ****Proton transverse emittance:**
**	****- At Booster intensity of 4.2E12/batch, ********H**** = 17 ********-mm-mrad, ********V**** = 14 ********-mm-mrad @ 8 ****	****	****	****GeV**
**	****- Coalesced beam @ 150 GeV in MI is ********H**** = ~19 ********-mm-mrad, ********V**** = ~24 ********-mm-mrad (large ****	****	****vertical emittance blowup may be instrumentation problem)**
**	****- Tevatron measures ********H**** = ~20-25 ********-mm-mrad, ********V**** = ~25 ********-mm-mrad @ injection**
**	****- “Calculated” emittance at low beta is ~20 ********-mm-mrad.  “Calculated” emittance uses ****	****	****	****measured luminosity, measured intensity, assumed bunch length factor of .6 and gives ****	****	****an estimate of average proton and pbar vertical and horizontal emittance – ****	****	****	****	****accuracy is ~25%**

- Overview for FY03

- 02/4/03

## Emittance (3)

**•  ****Antiproton transverse emittance:**
**	****- Core transverse emittance grows linearly with stack size.  ********average**** = 6 ********-mm-****	****	****mrad @ 140mA**
**	****- At 8 GeV in MI, ********H**** = 13 ********-mm-mrad, ********V**** = 10 ********-mm-mrad, becoming ********H**** = 14 ********-mm-****	****	****mrad, ********V**** = 11 ********-mm-mrad after coalescing**
**	****- Tevatron measures ********H**** ~ 25 ********-mm-mrad, ********V**** ~ 21 ********-mm-mrad @ 150 GeV**
**	****- RMS bunch length at low beta is ~2 nsec (~4 eV-sec)**

- Overview for FY03

- 02/4/03

## Agenda for FY03

**•  ****3 week shutdown in January**
**	****	****- C0 Lambertson removal; Recycler vacuum upgrades; Tevatron ****	****	****	****vacuum; CDF shielding; ....**
**•  ****February to late-July**
**	****	****- deliver luminosity; routine pbar shots to Recycler; up to 5 ****	****	****	****shifts/week dedicated studies; minimize shutdown days; ...**
**•  ****6 week shutdown in July**
**	****	****- Recycler vacuum; e-cooling civil construction; A0 ****	****	****	****	****modifications; Tevatron collimators; NUMI installation work; ****	****	****	****(full scope of work not yet determined)....**
**•  ****Continued running in Fall**
**	****	****- same as Feb. - July**

- Overview for FY03

- 02/4/03

## Integrated Luminosity Performance and “Stretch” Goal for FY03

- Overview for FY03

- 02/4/03

## Critical Projects for Luminosity

**•  ****A150/P150 beamlines – 20% in peak luminosity by 12/1/02  ****(missed)**
**- The original scope of the work -- reduction of injection oscillations and matching of beamlines has been ****	****done.   **
**- This was thought to be the major source of the problem (emittance blowup), but this turns out not to be the ****	****case.  **
**- Beam studies and calculations underway are aimed at understanding coupling and beam-beam effects in ****	****Tevatron as a source of emittance blowup.  **
** ****- Progress possibly limited by lack of beam study time.**
**• ****Tevatron transverse dampers – 20% in peak luminosity by 1/1/03  ****(missed)**
**- Transverse dampers have been completed.  **
** ****- Dampers used at 150 GeV with positive effect – Tevatron can run with lower chromaticity @ 150 GeV.**
** ****- Dampers are not used on the ramp and squeeze because excessive coupling causes the dampers to anti-****	****damp out-of-plane motion. **
** ****- ******** proton intensity has not been increased, which was intended to be the source of the 20% improvement ****	****in luminosity. **
**- Progress possibly limited by lack of beam study time.   **
**- **_**The  removal of the C0 Lambertsons will reduce transverse impedance, and that may make the beam more **_**	**_**stable so that possibly the proton intensity can increased after the shutdown anyway! **_

- Overview for FY03

- 02/4/03

## Critical Projects (continued)

**• ****C0 Lambertson replacement – 10% in peak luminosity by 3/1/03**
**- Completed in January shutdown.  Commissioning in progress.**
**• ****Accumulator bands 2&3 equalizers – 5% in peak luminosity by 5/1/03**
**- Installed during the January shutdown.  Will be commissioned in early February.**
**- Expect 7% decrease in Accumulator core emittances during shots to Tevatron.**
**• ****AP3 beamline – 5% in peak luminosity by 6/1/03**
** ****Found a plastic magnet cap in the beamline in January shutdown (been there for ~20 years).  Should ****	****give ~1-2******** emittance reduction.  **
**- Future efforts will be directed toward 8 GeV transfer reliability and faster shot setups.**
**• ****MI longitudinal dampers – 15% in peak luminosity by 7/1/03**
** ****Cavity fabrication and FPGA programming is in progress. **
**- High power amplifiers have been purchased.**

- Overview for FY03

- 02/4/03

## Critical Projects (continued)

**• ****Reliability – 1.5%/month in **_**integrated luminosity**_**  over 9 months**
**- Projects are getting done.  **
**- VFC replacement is 70% complete; cryo wet engine rebuild is complete.  **
**- # store hours/week has been better than anticipated (averaging 86 hrs/week since 10/1/02)-- ****	****partly because of reduced study shifts, partly from less downtime.  **
**• ****Stacking upgrades – 1.5%/month in **_**integrated luminosity**_**  over 9 months**
** ****Major emphasis has been on Debuncher momentum cooling, stacktail system, and yield into ****	****Debuncher (AP2 and target). **
** ****No real stacking improvements since mid-November when peak stacking rate of 13.1 mA/hr was ****	****achieved.  **
** ****Since then, MI intensity has been lowered on stacking cycles to accommodate miniBooNE operation ****	****and to help keep Booster losses tolerable.**
** ****Limited by study time. **

- Overview for FY03

- 02/4/03

## Other Projects

**•  ****Tevatron**
**vacuum improvements;  new Schottky detector;  new (or modified) BPM’s;  A0 lattice modification;  injection dampers;  tune monitoring and feedback;  collimators;  TEL upgrade;  instrumentation improvements;  continuing beam studies and calculations on beam-beam and beam stability; ....**
**•  ****Main Injector**
**continued coalescing improvements;  continued beam-loading compensation improvements;  instrumentation improvements;  new BPM’s;  2.5 MHz acceleration; ....**
**•  ****Pbar Source**
**flying wires;  quadrupole pickup;  1-q transverse damper; ....**
**•  ****Booster**
**new extraction Lambertson;  new collimators;  ramped correctors; ....**
**•  ****Recycler**
**vacuum improvements;  new BPM’s;  lots of machine studies;  instrumentation improvements; ....**

- Overview for FY03

- 02/4/03

## Summary

**•  ****Factor of 3.7 increase in peak luminosity in CY02**
**•  ****Increased stacking rate and Accumulator stack size**
**•  ****Significant improvement in Recycler operations**
**•  ****Reduced downtime**
**•  ****Progress on instrumentation**
**•  ****Improvements in theoretical understanding of issues**
**•  ****Plan of action for continuing improvements in luminosity**

- Overview for FY03

- 02/4/03