# Presentation: 529912

## AGS Intensity Upgrade(J.M. Brennan, I. Marneris, T. Roser, A.G. Ruggiero, D. Trbojevic, N. Tsoupas, S.Y. Zhang)

**Proton driver parameters and layout**
**Beam loss considerations**
**1.2 GeV Superconducting Linac**
**2.5 Hz AGS power supply and rf system**
**4 MW Upgrade**
**Bunch compressor ring**
**Cost estimate**

## AGS proton driver parameters

**	****1 MW AGS****	****AGS presently**
**Total beam power [MW]****	****1**** ****	****0.14**
**Beam energy [GeV]****	****24****	****24**
**Average current [********A]****	****42****	****6**
**Cycle time [ms]****	****400****	****2000**
**No. of protons per fill****	****1 ******** 10****14****	****(0.6 - 0.7) ******** 10****14**
**Average circulating current [A]****	****5.9****	****4.2**
**No. of bunches per fill****	****6****	****6 **
**No. of protons per bunch****	****1.7 ******** 10****13****	****~ 1 ******** 10****13**
**Time between extracted bunches [ms]****	****20 ****	****33**
**Rms bunch length [ns]****	****3****	****30**
**Peak bunch current [A]****	****400****	****30**
**Total bunch area [eVs]****	****5 ****	****15**
**Rms bunch emittance [eVs]****	****0.3****	****0.8**
**Rms momentum spread****	****0.005****	****0.001**

## AGS proton driver layout

**AGS**
**1.2 GeV ******** 24 GeV**
**0.4 s cycle time (2.5 Hz)**

**116 MeV Drift Tube Linac**
**(first sections of 200 MeV Linac)**

**BOOSTER**

**High Intensity Source**
**plus RFQ**

**Superconducting Linacs**

**To RHIC**

**400 MeV**

**800 MeV**

**1.2 GeV**

**0.15 s**

**0.1 s**

**0.15 s**

**To Target Station**

## Beam loss at H- injection energy

**	****AGS Booster****	****   PSR****	****SNS****	****1 MW AGS****	**
**Beam power, Linac exit, kW****	****3****	****   80****	****1000****	****50****	**
**Kinetic Energy, MeV****	****200****	****   800****	****1000****	****1200****	**
**Number of Protons N****P****, 10****12****	****15****	****   31****	****100****	****100****	**
**Vertical Acceptance A, ******** ********m****	****89****	****   140****	****480****	****55****	**
******2********3****	****0.57****	****   4.50****	****6.75****	****9.56****	**
**N****P**** /********2********3**** A), 10****12******** ********m****	****0.296****	****   0.049****	****0.031****	****0.190****	**
**Total Beam Losses, %****	****5****	****   0.3****	****0.1****	****3****	**
**Total Loss Power, W****	****150****	****   240****	****1000********1440****	**
**Circumference, m****	****202****	****   90****	****248****	****807****	**
**Loss Power per Meter, W/m****	****0.8****	****   2.7****	****4.0****	****1.8**

## Beam losses in AGS

**Major loss points****	****         Present AGS****	****           1 MW AGS**
**	****% particles****	****Beam power****	****% particles****	****Beam power**
**Injection and early accel.:**
**  ****Controlled****	****	****	****3.0 %****	****1.5 kW****	**
**  ****Uncontrolled****	****30 %****	****1.9 kW****	****0.3 %****	****0.2 kW**
**Transition****	**** 2.0 %****	****0.4 kW****	****1.0 %****	****2.9 kW**
**Total:****	****	****2.3 kW****	****	****4.6 kW**
**Injection modeled after SNS but much lower repetition rate and less foil traversals ******** Allow 30 times more beam loss**
**Transition losses are presently dominated by beam momentum spread required for AGS injection stacking. Direct injection should eliminate chromatic transition losses.**
**4.6 kW should be acceptable for hand maintenance.**

## AGS injection simulation

**Injection parameters:**
**Injection turns****	****360****	**
**Repetition rate****	****2.5 Hz****	**
**Pulse length****	****1.08 ms****	**
**Chopping rate****	****0.65****	**
**Linac ave./peak current****	****20 / 30 mA**
**Momentum spread****	******** 0.15 %****	**
**Inj. beam emittance (95%)****	********m****	**
**RF voltage****	****450 kV****	**
**Bunch length****	****85 ns****	**
**Longitudinal emittance****	****1.2 eVs****	**
**Momentum spread****	******** 0.48 %****	**
**Circ. beam emit. (95%) ****	****100********m**

## 1.2 GeV Superconducting Linac

**Beam energy ****	****0.116 ******** 0.4 GeV****	****0.4 ******** 0.8 GeV****	****0.8 ******** 1.2 GeV**
**Rf frequency****	****805 MHz****	****1610 MHz****	****1610 MHz**
**Accelerating gradient****	****11.9 MeV/m****	****22.0 MeV/m****	****21.5 MeV/m**
**Length****	****75.4 m****	****43.9 m****	****42.6 m**
**Beam power, exit****	****17 kW****	****34 kW****	****50 kW**

## New AGS main magnet power supply

**	****	****presently:**
**Repetition rate****	****2.5 Hz****	****1 Hz**
**Peak power****	****110 MW  ****	****50 MW**
**Average power****	****4 MW  ****	****4 MW**
**Peak current****	****4.3 kA        ****	****5 kA**
**Peak total voltage****	******** 25 kV ****	**** ******** 10 kV**
**Number of power converters / feeds****	****6****	****2**

## Distribution of current feeds

## AGS rf system upgrade

**Use present cavities with upgraded power supplies (two 300 kW tetrodes/cavity)**
**	****	****presently:**
**Rf voltage/turn****	****1 MV****	****0.4 MV**
**harmonic number****	****24****	****6 - 12**
**Rf frequency****	****~ 9 MHz****	****3 - 4.5 MHz**
**Rf peak power****	****3 MW**
**Rf magnetic field****	****18 mT**

## Bunch merging and compression

- 80 ns

- h = 241.2 eVs/bunch
- Adiabaticmerging:h = 6
- 100 kV/turn
- ~ 5 eVs/bunch

- h = 241 MV/turn

- Adiabatic quad pumping:

- 15 ns (3 ns rms)

## Towards 4 MW

**	****Upgrade I****	****Upgrade II****	****Upgrade III**
**Linac intensity/pulse****	****1.2 ******** 10****14 ****	****2.4 ******** 10****14 ****	****2.4 ******** 10****14 **
**Linac rep. rate****	****2.5 Hz****	****2.5 Hz****	****5.0 Hz**
**Linac extraction energy****	****1.2 GeV****	****1.5 GeV****	****1.5 GeV**
******2********3****	****9.6****	****14.9****	****14.9**
**Beam power****	****54 kW****	****144 kW****	****288 kW**
**AGS intensity/pulse****	****1.0 ******** 10****14**** ****	****2.0 ******** 10****14**** ****	****2.0 ******** 10****14**** **
**AGS rep. rate****	****2.5 Hz****	****2.5 Hz****	****5.0 Hz***
**Rf peak power****	****3 MW****	****6 MW****	****8 MW**
**Rf gap volts/turn****	****1 MV****	****1 MV****	****1.5 MV**
**AGS extraction energy ****	****24 GeV****	****24 GeV****	****24 GeV**
**Beam power****	****1 MW****	****2 MW****	****4 MW**
**Bunch area****	****5 eVs****	****10 eVs****	****10 eVs**
**Compressor ring****	****no****	****yes****	****yes**
**Symmetric cycle (0.1 s up, 0.1 s down) without flattop. **** **

## 4 MW AGS proton driver layout

**AGS**
**1.2 GeV ******** 24 GeV**
**0.2 s cycle time (5 Hz)**

**116 MeV Drift Tube Linac**
**(first sections of 200 MeV Linac)**

**BOOSTER**

**High Intensity Source**
**plus RFQ**

**Superconducting Linacs**

**To RHIC**

**400 MeV**

**800 MeV**

**1.5 GeV**

**0.1 s**

**0.1 s**

**To Target Station**

**24 GeV Superconducting Compressor Ring**

**24 GeV Superconducting Storage Ring**

## Compressor ring

**Small superconducting ring to compress a single 24 GeV, 10 eVs bunch to ****3 ns rms length. Small size reduces space charge tune shift and gap volt requirements.**
**Circumference****	****200 m**
**Energy****	****24 GeV**
**Dipole field****	****~ 4 Tesla****	**
**Packing factor****	****60 %**
**Transition gamma****	****~ 40         (d************/d******** < 4)**
**Momentum acceptance****	******** 5 %   (FFAG type lattice?)**
**Rf frequency ****	****6 MHz  (h = 4)**
**Rf Voltage per turn****	****200 kV**
**Bunch length compression (rms)****	****20 ns ******** 3 ns**

## Bunch compression

## Cost estimate