# Presentation: 686394

## Muon Collider Design Workshop - Summary  

- Muon Collider Design Workshop - Summary _** **_

## 	The annual Muon Collider Design Workshop (previously hosted at BNL) is aimed at bringing together all the groups working on various designs for Muon Colliders. The goal is to review and assess the current state of the concepts, simulation work and experiments. We shall examine practical limits on the performance of required technologies in attempt to focus future efforts towards a baseline collider scenario. The workshops will cover topics such as:
Proton drivers 
Muon cooling and demonstration experiments
Bunch recombination
Muon acceleration schemes 
Collider Ring and Interaction region design
Site boundary radiation
Detector concepts for energy frontier

- 	The annual Muon Collider Design Workshop (previously hosted at BNL) is aimed at bringing together all the groups working on various designs for Muon Colliders. The goal is to **review and assess the current state of the concepts, simulation work and experiments**. We shall examine practical limits on the performance of required technologies in attempt to focus future efforts towards a baseline collider scenario. The workshops will cover topics such as:
- Proton drivers
- Muon cooling and demonstration experiments
- Bunch recombination
- Muon acceleration schemes
- Collider Ring and Interaction region design
- Site boundary radiation
- Detector concepts for energy frontier

**Motivation & Goals**

## Program - Sessions

**Program - Sessions**

**COLLIDER SCENARIOS **
**PROTON DRIVER & RF **
**COOLING SIMULATIONS **
**FINAL COOLING**
**ACCELERATION **
**INTERACTION REGION**
**EXPERIMENTS & PLANS**
**SUMMARIES**

## Participants

**Participants**

## LEMC Scenario

- Rol Johnson

## Medium Emittance scheme of 2007

- Bob Palmer found a number of weak points with this scheme:
-   bunch length grows >1m during REMEX in 50T solenoids  bunch frequency of 200MHz can not be sustained  merging should be done before REMEX with all the losses due to merging and recooling;
-   “super-Fernow” (aka bucked coil) lattice has poor transmission (<50%) making the overall survival a dismal 4% (if Guggenheims are used for 6D cooling).
**Still I think that the idea is not hopeless, though modifications are necessary**

- Yuri Alexahin

## Parameters of Different MC options

- 			Low Emit.	High Emit.	MCTF07	MCTF08
- s  (TeV)				1.5
- Av. Luminosity (1034/cm2/s) *	2.7	1	1.33-2
- Av. Bending field (T)		10	6	6
- Mean radius (m)		361.4	500	500     	495
- No. of IPs			4	2	2
- Proton Driver Rep Rate (Hz)	65	13	40-60
- Beam-beam parameter/IP	0.052	0.087	0.1
- * (cm)			0.5	1	1
- Bunch length (cm)		0.5	1	1
- No. bunches / beam		10	1	1
- No. muons/bunch (1011)	1	20	11.3
- Norm. Trans. Emit. (m)	2.1	25	12.3
- Energy spread (%)		1	0.1	0.2
- Norm. long. Emit. (m)		0.35	0.07	0.14
- Total RF voltage (GV) at 800MHz	407103c	0.21** 	0.84**  	0.3†
- Muon survival N/N0		0.31 	0.07	0.2	?
- + in collision / proton		0.047 	0.01	0.03	?
- 8 GeV proton beam power	3.62*** 	3.2	1.9-2.8	?
- ---------------------------------------------------------------------------

## HEMC Scenario

- Bob Palmer

## HEMC Scenario

## Proton Driver

- Scott Berg

- Scott Berg

- Valeri Lebedev

## Big View of Muon Cooling....

**Big View of Muon Cooling....**

## Front End Capture/Phase Rotation & Cooling Studies

**-30m**

**30m**

**500 MeV/c**

**0**

**Drift and**
**Bunch**

**s = 89****m**

**s = 1m**

**Rotate**

**s = 125****m**

**s = 219****m**

**Cool**

**Front End Capture/Phase Rotation & Cooling Studies**

- Dave Neuffer

## Front end simulations

- Initial beam is 8GeV protons, 1ns bunch length

- Dave Neuffer

## Overview of Cooling Studies in the UK

- Chris Rogers

## Helical FOFO Snake Simulations

**3**

- Create rotating B field by tilting (or displacing) solenoids in rotating planes
-                             x*cos(k)+y*sin(k)=0, k=1,2,...
- Example for 6-cell period:
- Solenoid #		1	2	3	4	5	6
- Polarity		+	-	+	-	+	-
- Roll angle	 k 	0	2/3	4 /3	0	2 /3	4 /3

- Channel parameters:
- 200 MHz pillbox RF 2x36cm, Emax=16MV/m
- Solenoids: L=24cm, Rin=60cm, Rout=92cm,
- Absorbers: LH2, total width (on-axis) 6x15cm,
- Total length of 6-cell period 6.12m

**Helical FOFO Snake Simulations**

- Yuri Alexahin

## Phase space distributions

**Phase space distributions**

**6**

- z-v0*t

- “Emittances” (cm)		initial 		final
- 6D			 10.3		0.07
- Trans. average		1.99		0.29
- Longitudinal		3.75		1.46

- py

- x

- y

- px

- blue - initial, red - final

- p

**Why momentum acceptance is so large (>60%) in the resonance case?**

**Nice surprise:**
- Large 2nd order chromaticity due to nonlinear field components keeps both tunes from crossing the integer !

## Study of Ring Coolers for + - Colliders

- David Cline

## Initial Design of Liquid Li Lens

- Lens assembly w/ current discs and the primary and secondary coils
- Li D = 2.54 cm; L = 30.0 cm

**Lithium Lens for Muon Final Cooling**

- Kevin Lee

## Progress on Guggenheim RFOFO - Simulations

*RF*

*liquid H**2*

*solenoid*

- Pavel Snopok

## Progress on Design of Helical Cooling Channel

**Progress on Design of Helical Cooling Channel**

- Katsuya Yonehara

- Milorad Popovic

## Epicyclic Helical Solenoid

- Superimposed transverse magnetic fields with two spatial periods
- Variable dispersion function

- XY-plane

- k1=-2k2
- B1=2B2
*EXAMPLE*

- Andrei Afanasev

## VORPAL 3D Simulations with space-charge 

- R. Palmer’s ICOOL model

**Simulations of Muon Cooling With an Inverse Cyclotron**

- G4beamline model

- Terry Hart

- VORPAL 3D Simulations with space-charge

- Kevin Paul

## ...

- Remember that 1/e transverse cooling occurs by losing andre-gaining the particle energy. That occurs every 2 or 3 foilsin the frictional channel.

- Solenoid

- μ− In(3-7 MeV)

- μ− Out(6 keV)

- Resistor Divider

- Gnd

- HV Insulation

- First foil is at -2 MV, so outgoing μ− exit with 2 MeV kinetic energy.

- Solenoid maintains transverse focusing.

- μ− climb the potential, turn around, and come back out via the frictional channel.

- 10 m

- 20cm

- 1,400 thin carbon foils (25 nm), separated by 0.5 cm and 2.4 kV.

- -5.5 MV

- Device is cylindrically symmetric (except divider); diagram is not to scale.

- Tom Roberts

**Frictional Cooling**

## The MANX Proposal

_**DRAFT**_**   MANX following MICE at RAL   **_**DRAFT**_
- Robert Abrams**1**, Mohammad Alsharo’a**1**, Charles Ankenbrandt**1**, Emanuela Barzi2,
- Kevin Beard**1**, Alex Bogacz3, Daniel Broemmelsiek2, Yu-Chiu Chao3,
- Mary Anne Cummings**1**, Yaroslav Derbenev3, Henry Frisch4, Ivan Gonin2,
- Gail Hanson5, David Hedin7, Martin Hu2,
- Rolland Johnson**1**, Stephen Kahn**1**, Daniel Kaplan6,
- Vladimir Kashikhin2, Moyses Kuchnir**1**, Michael Lamm2, Valeri Lebedev2,
- David Neuffer2, Milord Popovic2, Robert Rimmer3, Thomas Roberts**1**, Richard Sah**1**,
- Linda Spentzouris6, Alvin Tollestrup2, Daniele Turrioni2, Victor Yarba2,
- Katsuya Yonehara2, Cary Yoshikawa2, Alexander Zlobin2
**1*****Muons, Inc.***
- 2*Fermi National Accelerator Laboratory*
- 3*Thomas Jefferson National Accelerator Facility*
- 4*University of Chicago*
- 5*University of California at Riverside*
- 6*Illinois Institute of Technology*
*7**Northern Illinois University*

## If MANX isn’t a prototype for NF or MC cooling, could it be?

- For example, if HPRF can’t be made to work, then you could
- match 6d MANX output to ~150 MeV vacuum RF section, (a la Fernow)
- accelerate 150 MeV, which would improve 6d emittance by factor of ~5.
- Inject into another MANX section, and iterate 9 times to reduce 6d emittance by a factor of a million in 10X30 = 300 m.

- Rol Johnson

## MICE Phases + MANX

**MANX in MICE (Conceptual)**

**MICE Phases + MANX**

## MANX Objectives

- Measure 6D cooling in a channel long enough for significant reduction of emittance
- Study the evolution of the emittance along the channel by making measurements inside the channel as well as before and after
**Test the Derbenev-Johnson theory of the HCC**
- Advance muon cooling technology

## Further Cooling Experiments

- Chris Rogers

## Study high pressure hydrogen gas filled RF cell

**Study high pressure hydrogen gas filled RF cell**

- Katsuya Yonehara

## Rapid Cycling Synchrotron

- Don Summers

## Prototype Arc design NS-FFAG

**Prototype Arc design NS-FFAG**

- ‘Racetrack’ RLA to accommodate large momentum range (~60%)

- Basic cell structure in ARC (combined function magnet with extremely strong focusing )

- Reference: Flexible Momentum Compaction Return Arcs for RLAs, D. Trbojevic, R.P. Johnson, EPAC, 2578-2580

- Large energy acceptance
- Very small orbit offsets
- Reduce number of arcs
- Very compact structure

**NS-FFAG (Non-Scaling Fixed Field Alternating Gradient)**

- Dejan Trbojevic

## NS-FFAG multi-pass  ‘Droplet’ Arc  

**NS-FFAG multi-pass  ‘Droplet’ Arc  **

- ,

- Guimei Wang

## IR Optics

- “Dipole first”				modified Oide

- Yuri Alexahin

## Nonlinear Detuning and Dynamic Aperture

**Normalized anharmonicities:**
**dQ1/dE1 =  ****0.25242152E+08**
**dQ1/dE2 =  ****0.19616977E+08**
**dQ2/dE2 =  ****0.18515914E+08**

- “Dipole first”				modified Oide

- Eliana Gianfelice

## Status of the Collider-IR design

****** ******** ****= 1cm**
****** ********c**** ~ 10****-5**** ******** 10****-4**
****** ****momentum acceptance ±1%**
****** ****Dynamic aperture ~ ****5******** for ************N ****= 25 ********m**** (HE option)**
****** ****Circumference ~ 3km**
**(all at the same time)**
**To proceed further to a realistic design a close collaboration between lattice designers and detector, energy deposition and magnet technology groups is a must.**

**Status of the Collider-IR design**

- Yuri Alexahin

## Muon Collider Detector Revision 

- Prepare G4Beamline to simulate beam-induced backgrounds in sensor arrays of a large detector in the low-beta region of a muon collider.
- Verify the simulations by comparing distributions and rates to other codes, such as MARS, and to analytic calculations.
- Consolidate existing NIU and other photon sensor performance data and extend them as needed with new measurements.
- Compare the apparent requirements from the preliminary G4beamline simulations for at least one muon collider scenario with the performance data to identify inconsistencies or areas where improvement is needed in the devices, electronics, IP design, or machine parameters.

- Mary-Anne Cummings

## Proton Driver & RF, Acceleration  Discussion

- How to transform Project X into a Proton Driver?
- Should linac be CW or pulsed?
- How many IR’s?
- How promising are new Induction Accel. ideas?
- MANX, MICE, & the 5-year plan
- Will MC be low, med, or high emittance?
- What were the highlights of this workshop?
- Questions about particular talks

- Chuck Ankenbrandt