# Presentation: 519867

## MANX at MTA

**Andreas Jansson**
**Fermilab**

## Foreseen MCTF Experimental R&D

- Low energy proton beam to MTA
- Foreseen since before, but delayed due to budgetary restrictions. We pushed for it, but not part of MCTF proposal.
- Proton intensity upgrade for MTA
- Part of MCTF proposal to Director
- Muon beam to MTA
- Initially to test Helical Cooling Channel, which is also part of MCTF proposal.

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## 6DMANX

**[Cummings *****et al*****, “A SIX-DIMENSIONAL MUON BEAM COOLING EXPERIMENT”, EPAC06]**

**Helical Cooling Channel**

**Default option: stick it in the MICE beamline at RAL...**
**	****         ... ****but, maybe there is another way to do it.**

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## First, a disclaimer

- Investigating a muon beam experiment does not constitute a decision.
- The (HCC) demonstration experiment should be done the way that makes most sense.
- We should agree on what we want to demonstrate, and to whom!
- Need simulations to make informed decision.
- Single particle a la MICE by Muons Inc?
- Macro-particle (pencil beam) by Fermilab MCTF
- Other bright ideas by anyone?
- Initial results by PAC07(?)

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Why at MTA?

- MTEST
- 	very low intensity, energy of muons on the high end,  issues with radiation shielding and compatibility with ongoing ILC tests, to cryo, rate limited by Main Injector availability
- MiniBoonewell matched energy, but no space (need new civil construction), no cryo, unclear availability (existing programme), relies on Booster availability
- MTA restricted space, muon energy on the low end, high beam availability, facility dedicated to muon R&D, cryo will be available
- (Pbar debuncher)
- 	not considered (compatibility with proton plan?), but if MECO becomes a reality should reconsider

**NB. A lot of the discussion is independent of location. **

**D. Broemmelsiek**

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Muon beam at MTA?

- Can we make a muon beam at MTA with suitable momentum and sufficient intensity?

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Target, pion capture and decay channel

- Carbon target in 6T solenoid.
- Quadrupole decay channel (PAC’01 design)

**N. Mokhov/V. Balbekov**

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Preliminary simulation results

- MARS model of target and decay channel (PAC’01 design 42m long).
- Working on simulations with shorter channel.
- Total yield ~1e-6.
- Emittance (rms, unnormalized) of ~500 Pi mm mrad

**N. Mokhov/V. Balbekov**

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Beam purity (preliminary)

- Main contaminant is π+ (50%), π- (~1%) and μ- (~1%).
- Protons are absorbed in target.
- Need to separate pions from muons
- Use a Tevatron electrostatic separator (Wien filter)?
- 2.5m long, 2MV/m, gives a differential kick of ~10mrad
- Many will be available, soon...
- Alternative: thin target to range out pions.
- Would affect muon momentum...

**Pi+**
**Mu+**

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Decay Channel in G4Beamline

- Implementing the Balbekov/Mokhov target and decay channel in G4BeamLine for comparison
- Eventually, should implement entire experimental setup

**Work in progress**

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Muon yield in G4Beamline vs MARS

- 400 MeV (kinetic energy) linac protons on 40cm carbon target in B=6T.
- Detector at 0.5m.
- So far, not very good agreement...

**G4BeamLine **
**v1.06**

**MARS**

**Work in progress**

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Preliminary MTA Muon Beam Parameters

- 250 MeV/c average muon momentum, 50MeV/c momentum spread
- ~1e6 muons per pulse maximum (peak rate of ~2e11 μ+/second).
- Expect to loose two orders of magnitude in reducing transverse emittance (simulations underway).

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Macro-particle experiment

- It is very hard to measure the emittance of a large beam, especially in the presence of non-linear forces.
- Use “pencil beam” as macro particle and scan the aperture!
- Beam position and angle easy to control and measure.
- Can use relatively simple detectors (10000 MIPS vs 1 MIPS).
- Insensitive to muon decays (average position is insensitive to 1 particle out of 10000).
- Can measure transverse non-linearities and acceptance.

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## 4D Raster Scan

**x’**

**x**

**x’**

**x**

**y’**

**y**

**y’**

**y**

**E**

**t**

**E**

**t**

**Beam **

**“****Pencil beam”**

**Macro-particle **

**Macro-particle **

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## 5D Raster Scan

**x’**

**x**

**x’**

**x**

**y’**

**y**

**y’**

**y**

**“****Pencil beam”**

**Macro-particle **

**Macro-particle **

**E**

**t**

**E**

**t**

**Macro-particle **

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Expected MANX cooling

- Note that when matching is included, MANX is currently _heating_ longitudinally!
- Could matching be improved?

**coupling**

- Matching

- MANX

- Matching

**K. Yonehara**

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## G4Beamline simulation

- Cooling term is given by the reduction in volume of  5D voxels bounded by raster points.
- Heating term is given by the beam emittance at the exit of the HCC (assuming zero initial emittance and far from equilibrium).
- Equilibrium emittance can be calculated!

**x [m]**

**y [m]**

**Distribution of initial zero **
**emittance beam after passing **
**thru HCC+matching (no RF)**

**G4beamline model from K. Yonehara**

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Pencil beam experiment layout

**Transverse **
**collimation**

**Momentum **
**collimation**

**Energy distribution measurement**

**Position and angle**
**measurement**

**Steering dipoles**

**Electrostatic**
**separator?**

**Decay channel**

**HCC**

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Schematic

**beam in**

**beam out**

**Spectrometer**

**Steering dipoles**

**Position and angle measurement**

**Spectrometer**

**Position and angle measurement**
**(plus emittance)**

**Position inside HCC**

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## First pass at Optics

- Dispersion free bend with space for momentum selection and momentum spread measurement.
- Matching into HCC with space for steering dipoles and diagnostic.
- Need to refine and add eg electrostatic separator.
- Need to simulate in eg G4BeamLine.

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Instrumentation

**Fiber tracker developed by PPD for MTEST**
**Single MIP sensitivity depending on fiber size and electronics**
**Can probably be used directly in beam lines**
**May be modified for use in LHe?**

**H. Nguyen *****et al***

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## What About the 6th Dimension?

- Near isochronous HCC is important for adding RF.
- Lowering the muon rate, one could do a dedicated run to measure time-of-flight distribution as well.
- Need to investigate sensitivity and error sources.

**Σ**

**Σ**

**start**

**stop**

**μ+**

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Possible extensions to the program

- “Simplest” way to add RF to HCC is to interleave HCC sections with RF sections.
- Could be added as a second phase.
- May also test pressurized RF only with muon beam.

**HCC with matching sections**

**HCC with matching sections + RF**

**Pressurized RF only**

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## To do (not exhaustive list)

- Investigate validity of macro-particle assumption (maximum emittance).
- Re-optimize HCC for 250MeV/c.
- Improved design and simulations of target, decay channel and pion separation.
- Refine the experimental setup, including beamline optics, collimator design and detectors.
- Simulate, simulate, simulate (to understand eg systematics)...

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Conclusions

- Fermilab director supportive of Muon Collider work
- Hopefully, this moral support will eventually translate into a fresh infusion of money.
- As part of the MCTF work, we are investigating the possibility of a muon beam at MTA.
- Could be used to test the HCC prototype magnet, but also for other things.
- We plan to study the performance of such an experiment in more detail, and (hopefully) compare to alternatives.
- Could use help, if anyone’s interested...

- LEMC Workshop, February 12-16, 2007

- 2/14/2007

## Slide 26

- LEMC Workshop, February 12-16, 2007

- 2/14/2007