# Presentation: 718781

## Run IIa Overview

**FNAL**
**5/13/02 AAC Review**

**Run IIa Overview**

## FNAL Accelerator Complex (picture)

- Status of Run IIa

- 04/12/02

## FNAL Accelerator Complex (words)

_**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 ~7-11 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 ~14 hours.**

- Status of Run IIa

- 04/12/02

## Luminosity Recipe

***(10******31****** cm******-2****** sec******-******1******)***

***f  *****= revolution frequency = 47.7 KHz**
***B *****= # bunches = 36**
*********r************r***** = relativistic beta x gamma = 1045**
*************** = beta function at IR = 35 cm**
***H***** = hourglass factor = .60 - .75**
***N******p****** ******, ******N******p***** = bunch intensities (E9)**
*********p****** ******, ************p***** = transverse emittances (********-mm-mrad)**
*********l****** *****= bunch length (cm)**

- }** ****"variables"**

- Status of Run IIa

- 04/12/02

## Status on Luminosity Parameters

** **

- Status of Run IIa

- 04/12/02

## Integrated Luminosity History

- Status of Run IIa

- 04/12/02

## Peak Luminosity and Intensity

- Status of Run IIa

- 04/12/02

## The Major Problems

**•  ****Transverse emittance in the Accumulator**
**	****	****- lattice, cooling**
**•  ****Long range beam-beam in the Tevatron**
**	****	****- helix, aperture**
**•  ****CDF and D0 backgrounds**
**	****	****- vacuum (?)**
**•  ****Everything else**
**	****	****- mismatch, coalescing, beam stability, lifetime....**

- Status of Run IIa

- 04/12/02

## Progress – Pbar Source

**•  **_**Investigations into source of transverse heating**_
**	****• ****IBS**
**•  **_**Longitudinal emittance preservation during unstacking**_
**•  **_**8 GeV beamline match between Accumulator and MI**_
**•  **_**Optimization of cooling during pbar extractions**_
**•  **_**Improvements in stacking rate**_

- Status of Run IIa

- 04/12/02

## Progress – Booster

**•  **_**Reliable operation at 4.5E12 protons/batch**_
**	****- (lack of Linac spare PA's is currently a problem)**
**•  **_**Recommissioning of longitudinal dipole mode dampers**_
**•  **_**MiniBooNE commissioning has started**_

- Status of Run IIa

- 04/12/02

## Progress – Main Injector

**•  **_**Reliable operation at >4E12 protons/batch on stacking cycles**_
**•  **_**Reliable operation at 280E9 protons/bunch after coalescing**_
**•  **_**Commissioning of 2.5 MHz beam loading compensation**_
**•  **_**Partial commissioning of 53 MHz beam loading compensation**_

- Status of Run IIa

- 04/12/02

## Progress -- Tevatron

**•  **_**"DC beam" fix**_
**•  **_**Low beta squeeze "step 13" fix**_
**•  **_**Lifetime improvements at 150 GeV and up ramp (in progress)**_
**	****• ****Injection helix improvement**
**	****• ****Octupole commissioning**
**•  **_**Instrumentation improvements**_

- Status of Run IIa

- 04/12/02

## Plans

**• ****Start commissioning new Accumulator lattice for shots (this week)**
**• ****Shoot from larger stacks (more pbars but larger emittances)**
**• ****Shutdown to install new core cooling tanks (June 3)**
**• ****Commission MI pbar injection dampers**
**• ****Commission feedforward beamloading compensation for pbars (before June 3?)**
**• ****Continue studies on MI transverse and longitudinal emittance growth**
**• ****Investigate ****MI-8 to MI lattice match**
**• ****Continue with new injection helix in Tevatron ("new-new" injection helix this week)**
**• ****Continue commissioning octupole circuits.  Try using TEL for beam stability @ 150**
**• ****Continue commissioning dampers in Tevatron**
**• ****Continue commissioning diagnostics in Tevatron**
**• ****Vacuum improvements during June shutdown (F11, C49, ......) to reduce backgrounds**
**• ****Aperture improvements (Fall shutdown)**
**• ****Continue routine pbar shots to the Recycler**

- Status of Run IIa

- 04/12/02

## Milestones (Jan. 2002)

- Status of Run IIa

- 04/12/02

## Requirements for Milestones

**• ****"increase proton intensity" – ****complete; current max. is 198E9/bunch**
**• ****"improve MI->Tev pbar xfer efficiency" – ****currently at ~88% (probably requires ****	****improved 150 GeV aperture for 100%); overall Tevatron efficiency is 55-60%; lifetime ****	****at 150 GeV and ramp being worked on; LB squeeze efficiency ~97%**
**• ****"improve 8 GeV pbar transport" – ****lattice/steering "complete" but refinements ****	****being tried; ****current efficiency is ****	****95%; should improve with smaller pbar emittances; ****	****MI pbar injection damper to be commissioned in May**
**• ****"reduce Acc. Core heating" –**** ****commissioning of Accumulator "shot" lattice to ****	****commence this week**
**• ****"improve pbar coalescing" – ****currently at 85%; 53 Mhz beam loading ****	****compensation commissioning in progress**
**• ****"improve shot setup time" – ****typical best is 2 hours if nothing goes wrong; want to ****	****reduce this to 1 hour eventually; not concentrating on this now**
**• ****"further increase proton intensity" – ****53 Mhz beam loading compensation ****	****commissioned for coalescing****; 150 GeV lifetime in Tevatron being worked on; Tevatron ****	****dampers being worked on**
**• ****"upgrade Acc. core cooling" – ****installation in 6/03 – 6/17 shutdown**
**• ****"reduce downtime" – ****currently running at 26%; goal is 20%**

- Status of Run IIa

- 04/12/02

## Integrated Luminosity Performance and Goal

- Status of Run IIa

- 04/12/02

## Summary

**•  ****Progress is being made but is slower than hoped for**
**•  ****The plan formulated in January is still fundamentally**
**	****sound**
**• ****Run II is hard, but at least the accelerator physics ****	****issues are interesting**

- Status of Run IIa

- 04/12/02