# Presentation: 351550

## Report From Run IIandWhat We Are Doing To Support It

**David Harding**
**21 May 2002**

## Fermilab Operates the Highest Energy Particle Accelerator in the World

## Run II Status

**Run IIa – now;  Run IIb – later; Smooth transition**
**Goal: High Integrated Luminosity**
**Accelerators struggling...**
**Initial luminosity**
**Luminosity lifetime**
**...****but so are experiments**

## Cockroft-Walton
Linac
Booster
Main Injector
Debuncher
Accumulator
Tevatron
Recycler

MiniBooNE
NuMI
Switchyard/Meson 120
NTF
RDF

**Cockroft-Walton**
**Linac**
**Booster**
**Main Injector**
**Debuncher**
**Accumulator**
**Tevatron**
**Recycler**
**MiniBooNE**
**NuMI**
**Switchyard/****Meson 120**
**NTF**
**RDF**

_***Fermilab***_

## FNAL Accelerator Complex

- From Mike Church AAC presentation 13 May 2002

## 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"**

- From Mike Church AAC presentation 13 May 2002

## Integrated Luminosity History

- From Mike Church AAC presentation 13 May 2002

## Peak Luminosity and Intensity

- From Mike Church AAC presentation 13 May 2002

## 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....**

- From Mike Church AAC presentation 13 May 2002

## Plans

**• ****Start commissioning new Accumulator lattice for shots (last week)**
**• ****Shoot from larger stacks (more p-bars but larger emittances)**
**• ****Shutdown to install new core cooling tanks (June 3)**
**• ****Commission MI p-bar injection dampers**
**• ****Commission feed-forward beam loading compensation for p-bars (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 p-bar shots to the Recycler**

- From Mike Church AAC presentation 13 May 2002

## Integrated Luminosity Performance and Goal

- From Mike Church AAC presentation 13 May 2002

## 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**

- From Mike Church AAC presentation 13 May 2002

## What is our role in Run II and elsewhere?

**New Projects**
**Build new magnets**
**Refurbish old magnets**
**Build other stuff**
**Upgrades**
**Improve performance**
**Improve reliability**
**Maintenance**
**Manage inventory of spare magnets**
**Execute repairs as needed**
**Measurements**
**Prototyping of new designs**
**Adjust new, rebuilt magnets in production**
**Certify new, rebuilt magnets**
**Characterize performance**

## People

**Accelerator Support Group**
**David Harding**
**Sasha Makarov**
**Bill Robotham**
**(John Carson)**
**(Jeff Brandt)**
**Ray Hanft (G)**

**Many more**
**Process Engineering**
**Assembly**
**Tooling**
**Design/Drafting**
**Material Control**
**Development and Test (MTF)**
**Jamie Blowers**
**Vladimir Kashikhin**
**Luciano Elementi**
**Jay Hoffman**
**Tom Nicol**
**Rodger Bossert**
**And more**

## Cockroft-Walton
Linac
Booster 
Main Injector 
Tevatron 
Debuncher 
Accumulator 
Recycler 

MiniBooNE 
NuMI 
Switchyard/Meson 120 
NTF
RDF 

**Linac**
**Booster ******
**Main Injector ******
**Tevatron ******
**Debuncher ******
**Accumulator ******
**Recycler ******
**MiniBooNE ******
**NuMI ******
**Switchyard/****Meson 120 ******
**NTF**
**RDF ******

_***Fermilab***_

## Recent Booster Projects

**New design 400 MeV Lambertson**
**New design extraction septum magnet**
**New design dipoles for 8 GeV transfer line**
**Measurements of Booster gradient magnets (D&T/MTF) ******

## 400 MeV Lambertson Replacement

**Started as a project to build spare**
**Decided to try to reduce stray field to 1/10**
**Design/drafting**
**Fabricate**
**Test**
**Modify**
**Repeat**

## Extraction Septum Magnet Replacement

**Old magnet can’t handle MiniBooNE repetition rate**
**250 ********sec half sine wave**
**23 kA peak**
**15 Hz rep rate**
**Minor modifications burned up**
**Start over with new design**
**Fabrication**

## 8 GeV Dipole Replacement (EDWA)

**Current magnet refurbished EPB dipole**
**Aperture too small**
**Almost no extra room outside**
**New design**
**Fabrication**

## Main Injector Improvements

**New insulation scheme for quadrupoles**
**New QXR magnet**
**New 7.5 MHz RF cavities**

## New Insulation Scheme for Quadrupoles

**IQC and IQD quadrupoles failing in service**
**Autopsy showed cracked epoxy insulation**
**New insulation design vacuum impregnates coils separately from core**
**Rebuilding magnets**
**Building new spare magnets**
**Building extra spare coils**

## New QXR Magnet

**High frequency quadrupole to control structure of “slow” spill during resonant extraction**
**Air core**
**New requirements compared to the ones we originally built**
**Design**
**Fabricate**

## 7.5 MHz RF Cavity

**New capability for manipulating beam**
**We provide mechanical design and fabrication**
**Specifications changing, so RF design not yet settled**

## Antiproton Source (P-Bar)

**Cores for new pulsed dipoles ******
**Rebuild toasted 6-4-120 dipole**
**Rebuild failed “Modified B1”**
**Repair SMA magnets when they break**
**New pulsed septum magnets ******

## Rebuild 6-4-120 Dipole Magnet

**Blocked water passage**
**Toasted insulation**
**Coil to core short**
**Cannibalized coil from another magnet**
**Need to reinsulate coils**

## Rebuild “Modified B1” Dipoles

**Compared to B1 dipoles**
**Different length**
**Different pole shape**
**Different coil**
**Different assembly**
**Vacuum impregnate coil**
**New manifolding**

## SMA Magnets

**Fragile, so occasional water leaks**
**Easy to repair, so little motivation to improve**

## Recent Tevatron Upgrade Projects

**Retrofit selected spools with “Recoolers”**
**Locally lower temperature of 1-phase helium in ring with heat exchangers to enhance performance of accelerator**
**Retrofit power feed spools with high temperature superconducting leads**
**Improve helium management**
**Develop experience with high temperature superconductor**
**Replace spool corrector lead feed-throughs**
**Reduce helium leaks**
**Improve reliability**
**Pulse Forming Lines (PFL) for kickers  ******
**Assembly labor**
**Electrostatic separators ******

## Heat Exchanger Being Added to Spool

**Engineering**
**Prototype built and studied**
**Initial 14 spools complete**
**Spools installed and work as advertised**

## High Temperature Superconducting Power Leads

**Engineering**
**Two spools were retrofitted and studied as R&D project**
**Two vendors**
**One spool installed**
**More spools being retrofit as Accelerator Improvement Project**
**Two done**
**Will continue as spools become available**

## Retrofitting Corrector Leads

**Engineering & prototypes**
**Install on spools in tunnel**
**10 of 24 houses retrofitted**
**Intense effort in limited access periods**
**Further work dependent on access**
**Two technical issues being addressed**

## Approach to Maintenance

**Manage a pool of spares**
**Good magnets**
**Awaiting repair**
**When the pool falls below the specified threshold**
**Repair enough magnets to restore the level agreed upon**
**Start with the easiest work, best performing devices**
**This requires**
**Good records**
**An inventory of parts**
**Production and test facilities**
**Trained technicians, engineers, physicists, support staff**
**Need depth to respond to crisis**

## Failed Magnets

**Dipoles and quadrupoles**
**Problems are at the ends and most can be repaired**
**Permanently lose one dipole/year.**
**Permanently lost one quadrupole in last ten years**
**Low beta quadrupoles**
**High profile**
**Few of them, so subject to fluctuations**
**So far have been able to repair all damage**
**Spools**
**Lots of different kinds, so spares inventory complicated**
**We’re losing them**
**But some flexibility in use**

## Tevatron Dipole in Need of Attention

## “Typical” Low Beta Q3 Repair

_***“***__***Typical” Low Beta Q3 Repair***_

## Spool Safety Lead Failure

## Recycler

**Rework LEP dipole correctors  ******
**Electron cooling**
**0.5 Ampere beam of 4.3 MeV electrons**
**Electron cooling gun solenoid**
**Electron cooling gun solenoid, again**
**Electron cooling 2-m solenoids**

## Electron Cooling Solenoids

**Transfer energy from antiprotons to electrons traveling at same speed**
**Ten 2-m solenoids keep intense, low-energy electron beam under control**
**Many turns precisely positioned**

## MiniBooNE

**Refurbish lots of magnets**
**6-3-120 dipoles**
**3Q120 quadrupoles**
**3Q60 quadrupoles**
**Vernier dipoles (4-4-30’s)**
**LEP correctors**
**LEP quadrupoles**
**Electron cooing ring quadrupoles**
**New permanent quadrupoles – Recycler style**

## 6-3-120 Dipoles

**Corrosion of core from adverse storage conditions**
**Clean water passages with Rydlyme****®**
**Now can’t get Rydlyme****®**** out!**

## Permanent Magnet Quadrupoles

**Same as Recycler**
**Remember how to do it in IB2 instead of MP9**
**Documentation!**

## NuMI

**Refurbish lots of magnets ******
**EPB dipoles**
**B2 dipoles**
**6-3-120 dipoles**
**3Q120 quadrupoles**
**3Q60 quadrupoles**
**New magnets ******
**Lambertson magnets (FMI)**
**Trim dipoles (FMI)**

## Summary

**Support for Run II Is Essential**
**Magnet upgrades are useful**
**Failures happen and must be repaired**
**Measurements are needed**
**Technical Division and Beams Division are studying hardware “vulnerabilities”**
**The Fermilab magnet program stands ready to implement any recommendations**
**More spares**
**New magnets**
**A healthy program is necessary to support Run II**