# Presentation: 676155

## Project X to μ+-μ- Collider

- David Neuffer
- Fermilab

## Introduction 

**Can Project X provide beam for ****μ****+****-****μ****-**** Collider?**
**Need > ~ 2MW**
**Use “baseline” X as starting point**
**0.36 MW **8 GeV Linac
- 5Hz, 5.6 × 1013 p/pulse
- Recycler for charge-exchange stacking (3 cycles)
**X feeds Main Injector for 2 MW at 120 GeV**
**1.4s cycle  **
**Uses only 3 (of 7) project X pulses**

## Project X to 120 GeV MI

## H- Injection – 3 Linac pulses

- Project X Overview - McGinnis

## Comments

**Can obtain 2+ MW from main injector at 120 GeV**
**3 X-linac pulses**
**1.4s  (80 GeV/cycle-s)**
**Need buncher ring at 120 GeV to form into short bunches to be extracted onto target **
**h=21 obtains 15 Hz bunches (1.9MHz rf)**
**Compression to < ~1m bunches probably OK **
**120 GeV not optimum for soft pion production**
**Lower energy better (?)**
**Shorten cycle; use more linac pulses**
**Shortest cycle using all bunches is 0.6s -56 GeV p  **

## Proton Beam Power

- Project X Overview - McGinnis

## 56 GeV Scenario

**Uses all Linac protons**
**3 Linac pulses**
**Cycle MI at 0.6s/cycle**
**Transfer to 56 GeV buncher**
**Form into 9 (?) bunches**
**(in ~0.2 s)**
**Remove bunches**
**Over 0.4 s **
**0.05 s between injections**
**20 Hz Collider pulses**

## Project X Layout

- Project X Overview - McGinnis

- 56 GeV fast extraction spill
- 1.5 x 1014 protons/0.6sec
- 2 MW

**8 GeV H****-**** Linac**
**9mA x 1 msec x 5 Hz**

- Stripping Foil

**Recycler**
**3 linac pulses/fill**

**Main Injector**
**0.6 sec cycle**

- Single turn transfer @ 8 GeV

**0.6-8 GeV ILC Style Linac **

- 0.6 GeV Front End Linac

**Buncher ring**
**h =9 (?)**

**To ****μμ**** Collider**

## New Buncher Ring (56 GeV)

**For Single turn transfer, must be ~MI size **
**C= 3.32 km, ****γ****T**** ****≈ 20**
- 	Bρ/R = Bave= 0.35 T  - permanent magnet possible
**Rebunching rf**
**Compress 3320/9  to ~1m (rms) (in <0.2s)**
- ~ **100× ** bunch-length reduction (**δ****E ×100**)
**δ****E: **2 MeV  -> 200MeV
- Sawtooth ~OK
- 0.56MV

## Shorter Buncher Ring

**Bunching much easier in smaller ring**
**X 1/4 (B****ave ****= 1.4T) normal-conducting, C = 830m**
**X 1/8 (B****ave ****= 2.8T) superconducting, C=415m **
**Can stack ~batches transversely (4 or 8)**
**Increases transverse emittance, losses**
**Longitudinal emittance not increased**
**Compression to short bunches**** much**** easier**
**~9 bunches OK  (~0.04s to bunch 0.2 MV, ~53MHz  to hold at < ~1ns rms)**
**~3ns -> 2 -> 1+ ns     **

## Sample Collider Parameters

| Parameter | Symbol | Baseline Value |
| --- | --- | --- |
| Collision Energy | 2E | 4 TeV |
| Luminosity | L | 41034 cm-2-s-1 |
| Collider cycle frequency | fo | 15 Hz |
| ’s per collider bunch | N | 1.21012 |
| Transverse emittance  | N | 25       mm-mr |
| Collision parameter | * | 0.003m |
| Beam-Beam tune shift |  | 0.052 |
| Beam size at collision  |  | 2 |
| Long. Emittance | L | 70        mm-r |
| Momentum spread | p/p | 0.12 % |
| Storage turns | ns | 900 |
| Proton Driver parameters |  |  |
| Proton Energy | Ep | 56 GeV |
| Driver Frequency | fp | 1.67  Hz |
| Protons/driver cycle   | nBNp | 1.681014 |
| Driver Power | Pp | 2.5 MW |
| Number of compressed bunches | nB | 9 |
| Intensity per bunch | Np | 1.871013 |
| Muons per initial proton | /p | 0.065 |

- μ/p= 0.4×2.33×0.07
-      = 0.065

- From RP scenario

## Upgrade Options

**Increase Linac pulse length (1 to 3 ms)**
**If RR, MI can handle the intensity ... **
**2.5MW -> ****7.5MW**
**L × 9, ****δν**** × 3 -> (0.16)**
**Increasing f****o****  (5 Hz -> 10 or 15) doesn’t help**
**(in this scenario...)**
**Design is 3 pulses/cycle; (could reduce 56 GeV)**
**extra linac cycles for other users **
**But upgraded Linac could feed 8 GeV driver**
- Ankenbrandt, Popovic
**3*2*0.35 =2.1 MW**
**(Accumulator and Buncher 8 GeV rings needed) **
**MI, RR not needed**

## Summary

**Project X Linac could feed ****μ****+****-****μ****-**** Collider**
**MI at 50 to 120 GeV can produce 2MW**
**Requires Rebunching Ring at MI extraction**
**Project X Linac upgrades can increase intensity**
**or change scenario**
**MuCool note 517**

## Not quite an engineering design...