# Presentation: 091145

## Neutrino Factories and Muon Ionization Cooling Channels

**D. Errede**
**HETEP University of Illinois**
**17 March, 2003**

## Why build a Neutrino Factory?

**(Physics, of course)**

**What does a Neutrino Factory look like?**

**In particular, what is an ionization cooling**
**channel?  What has the University of Illinois **
**been doing with respect to a cooling channel?**

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## Slide 3

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## The Physics of Neutrinos

**Neutrino masses**
**    ****(pattern of the all fermion masses)**
**Neutrino oscillation parameters**
**    ****(fill in the CKM matrix for leptons)**
**CP Violating processes in the Lepton Sector**
**    ****(origin of baryon-antibaryon asymmetry in**
**     ****our universe?)**
**GUTS: relating properties of quarks and leptons**
**                 ****Is there a grand unified scheme?**

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**  **

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## The Physics of Neutrinos

- Standard form for Mixing Matrix
- connecting weak and mass eigenstates
- are the 4 real parameters that describe the mixing...   0 implies
- CP violation.  (phase between 0 and 2

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## The Physics of Neutrinos

**Connect two weak eigenstates with the**
**    ****evolution operator – involves Hamiltonian H****0**
**Use two assumptions:**
**  ****m1 < m2 << m3  and**
**  ****dM****2**** = dm****2****atm**** = dm****2****32**** ~ dm****2****31  ****we get**

- And something similar but more complicated for 

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## The Physics of Neutrinos

**The sign of**** ********m****2 ****:    solar neutrinos**
**Matter effects : MSW (Mikheev, Smirnov, Wolfenstein)**
******e ****interacts with electrons in matter through the charged current interaction.  This adds a term to the evolution operator****.**
** **
**There is a resonance in matter near a = 1 for typical values of sin****2****2******** ****(10****-3**** - 10****-2****)**
**    “****a” depends on N****e****, G****F****, ****E********, ********m****2 ****. **
**    ******** ****=**** ********12 ****, ********13**

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## The resonance applies to neutrinos for positive dm2 and antineutrinos for negative m2.

Thus we can get the mass hierarchy.
-----m3  
                                                             -----------m2
                                                             -----------m1

                 OR
-----------m2
-----------m1        
                               -----m3 

**Thus we can get the mass hierarchy.**
**-----m3  **
**                                                             ****-----------m2**
**                                                             ****-----------m1**
**                **
**                 ****OR**
**-----------m2**
**-----------m1        **
**                               ****-----m3 **

- The Physics of Neutrinos

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## The Physics of Neutrinos

_**3 Plausible Sets of Values**_** **

- 1              2             3

- J - Jarlskog factor a measure of CP violatioin

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## J = c12 c132 c23 s12 s13 s23 sin
Jarlskog J-factor a measure of CP violation

CP Operation: C(eL) = eL
                           P(eL) = eR

CP Violating Process:

For example:                                   in vacuum

**Jarlskog J-factor a measure of CP violation**
**CP Operation: C(********e****L****) = ********e****L**
**                           ****P(********e****L****) = ********e****R**
**CP Violating Process:**
**For example:                                   in vacuum**

- ...

- The Physics of Neutrinos : **CP VIOLATION**

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## The Physics of Neutrinos

_**CP Violating Processes**__** **__**in the Lepton Sector**_
- Why is this interesting/fun/exciting?
- A possible explanation for Baryogenesis.
- (So far CP violating processes in the **b** quark sector are insufficient to explain baryogenesis)
-                          _**A SCENARIO**_
- Heavy Neutral Leptons: Majorana neutrinos through
- see-saw mechanism produces a light neutrino pair and a heavy neutrino pair.
- N       e- H+   or e+ H-   (both massless particles because this is occuring before EW symmetry breaking).

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## The Physics of Neutrinos

- CP Violating processes provides excess of e+,,+
- over e-,,-  before EW phase transition.
- Andrei Sakharov says we also need non-equilibrium
- conditions so that these processes are not driven to equalize the numbers.
- Standard Model nonperturbative processes violate B, L, but
- conserve B-L.  Churns lepton+’s into baryon material.
-                                                    Thank you Boris Kayser

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## The Physics of Neutrinos

- CP Violation in the Lepton Sector
- What would this have to do with CP violating processes in the low mass neutrino sector?
- We don’t know, but certainly CP violation in leptons at low mass makes CP violation in leptonic interactions at high mass scales more plausible.

- GUTs: one can also imagine unifying quarks and lepton
- such that their CKM matrices are also related.  We won’t
- understand this until all the parameters are measured.

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## Neutrino Factory

**High intensity beam on target to produce particles (********’s) for a secondary beam.  - ****Proton Driver  + Target**
**Collects ********’s, allow them to decay into muons, spread bunch (large ********E) and then perform phase rotation – ****Drifts + Induction Linacs**
**Reduce energy (and emittance) between induction linacs – ****Minicooling**
** ****Adiabatically change from one lattice to the next lattice – ****Matching Sections**** **
**Divide long bunch (~100 m) into short bunches that cooling section can handle - ****Buncher**

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## Neutrino Factory

**6.****	****Reduce beam emittance – ****Cooling Channels**
**7.****	****Accelerate to energy and emittance size that the next recirculating accelerators can handle - ****Linac**
**Accelerate from 2.8 GeV to 20 GeV – ****Recirculating Linear Accelerators (RLA’s)**
**Circulate muons and let some decay on production straight – ****Muon Storage Ring**
**Make measurements on neutrino interactions – ****Near and Far Detectors**

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## Slide 17

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## Neutrino Factory: Proton Driver

**Based on Feasibility Study 2 version of a neutrino factory...hence set at Brookhaven Natl Lab   **
**AGS proton driver uses existing ring, bypasses existing booster and introduces 3 new superconducting linacs.**

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## Neutrino Factory: AGS Proton Driver Parameters

| Total beam power (MW) | 1 |
| --- | --- |
| Beam Energy (GeV) | 24 |
| Average beam current (A) | 42 |
| Cycle time (ms) | 400 |
| Number of protons per fill | 1 x 1014 |
| Average circulating current | 6 |
| No. of bunches per fill | 6 |
| No. of protons per bunch | 1.7 x 1013 |
| Time between extracted bunches (ms) | 20 |
| Bunch length at extraction, rms (ns) | 3 |
| Peak bunch current (A) | 400 |
| Total bunch area (eV-sec) | 5 |
| Bunch emittance, rms (eV-sec) | 0.3 |
| Momentum spread, rms | 0.005 |

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## AGS Proton Driver Layout

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## Neutrino Factory: Superconducting Linacs

- Period

**Configuration of the cavities within the cryo-modules**

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## AGS Injection Parameters

| Injection turns | 360 |
| --- | --- |
| Repetition rate (Hz) | 2.5 |
| Pulse length (ms) | 1.08 |
| Chopping rate (%) | 65 |
| Linac average/peak current (mA) | 20/30 |
| Momentum spread  | +/- 0.0015 |
| Norm. 95% emittance (m rad) | 12 |
| RF Voltage (kV) | 450 |
| Bunch length (ns) | 85 |
| Longitudinal emittance (eV-s) | 1.2 |
| Momentum spread | +/- 0.0048 |
| Norm. 95% emittance (m rad)
 | 100 |

**AGS Injection Parameters**

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## AGS Proton Driver

- Bunch pattern for using harmonic 24 to create 6 bunches

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## Neutrino Factory : Target

**Energy on target 24 GeV, baseline beam power 1 MW,**
**Pion momentum distribution peaks at 250 MeV, **
** ****<p****T****> = 150 MeV  ********  large angles coming off target....**
**Capture with 20 Tesla solenoid (r = 7.5cm, p****Tmax****= 225 MeV).**
**Actually a horn which “tapers” to 1.25 T (r= 30cm,**
** ****p****Tmax****= 67.5 MeV)**
**(A horn converts transverse momentum into longitudinal momentum.)**
**Target:  High Z ******** maximize yield of  ********/p **
**             ****Goal of ****2 10****20**** muon per year (****10****7**** seconds) decaying in detector direction, 50 kT, 1800 km away.**
** **

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## Neutrino Factory : Target Z

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## Neutrino Factory : Target

**Liquid Hg jet target chosen for maximum yield.**
**Need to handle 1 – 4 MW beams.**
**Want ****v****jet**** ****= 30m/s to resupply Hg.   Tests achieved 2.5 m/s to date.  ( 30m/s only resupplies mercury before next**
**     ****bunch on average – 6 x 2.5 Hz = 15/sec )**

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## Carbon Target tested at AGS (24 GeV, 5E12 ppp, 100ns)
Probably OK for 1.5 MW beam ... limitation: target evaporation

**Carbon Target tested at AGS (24 GeV, 5E12 ppp, 100ns)**
**Probably OK for 1.5 MW beam ... limitation: target evaporation**

- Target ideas for 4 MW: Water cooled Ta Spheres  (P. Sievers), rotating band (B. King), conducting target,  Front-runner = Hg jet

- 13 Tesla

- CERN/Grenoble Liquid Hg jet tests in 13 T solenoid
- Field damps surface tension waves

- 0 Tesla

- BNL E951: Hg Jet in AGS beam
- Jet (2.5 m/s) quickly re-establishes itself.  Will test in 20T solenoid in future.

-          t = 0            0.75 ms          2 ms              7 ms            18 ms

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## Neutrino Factory : Drifts and Induction Linacs

**Beam has large energy spread.**
**Drift allows beam to spread out to a long bunch length.**
**Induction linacs accerlate late muons (lower energy) and decelerate early muons  (higher energy).**

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## Neutrino Factory : Drifts and Induction Linacs

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## Neutrino Factory : Drifts and Induction Linacs

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## Neutrino Factory : Drifts and Induction Linacs

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## Neutrino Factory : Drifts and Induction Linacs

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## Slide 33

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## Neutrino Factory : Drifts and Induction Linacs

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## Neutrino Factory : Minicooling in Drifts and Induction Linacs

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**Neutrino Factory : Buncher and Cooling Channel**

- In order to fit muon beam into cooling lattice the Buncher
-  separates the ~100m long trail of muons into rf buckets.
- The cooling channel (P**nominal** = 200 MeV) then reduces
-  the transverse emittance to a level acceptable for acceleration to
-  20 GeV.

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- Momentum-time distributions through the buncher

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## Neutrino Factory : Buncher and Cooling Channel

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- Momentum-time distributions through the buncher

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## Neutrino Factory : Cooling Channel

**Neutrino Factory : Cooling Channel**
**Lattice Cell**

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## Neutrino Factory : Cooling Channel

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## Neutrino Factory : Cooling Channel

**Neutrino Factory : Cooling Channel**

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**Notes:**
B field of SFOFO channel

## Neutrino Factory : Cooling Channel

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## Neutrino Factory : Cooling Channel

**Neutrino Factory : Cooling Channel**

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## Neutrino Factory : Cooling Channel

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## Neutrino Factory : Cooling Channel

**Neutrino Factory : Cooling Channel**

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## Neutrino Factory : Cooling Channel

**Neutrino Factory : Cooling Channel**

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## Absorber : Forced Flow Design

**Absorber : Forced Flow Design**

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## Approximate Equation Transverse Emittance in a step ds along the particle’s orbit:

- First term is the Ionization Energy Loss (Cooling) Term
- Second term is the Multiple Scattering (Heating) term

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## Absorber Aluminum Window Pressure/Burst Testing

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## MUCOOL:  UIUC Absorber Instrumentation Project 

**MUCOOL:  UIUC Absorber Instrumentation Project**

**Zach**
**Conway**
**Mike **
**Haney**
**Debbie**
**Errede**

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## MUCOOL RF R&D 

- _High Power 805 MHz Test Facility_12 MW klystron
- Linac-type modulator & controls
- X-Ray cavern
- 5T two-coil SC Solenoid
- Dark-current & X-Ray instrumentation

- Need high gradient cavities in multi-Tesla solenoid field

- Concept 1 – open cell cavity withhigh surface field

- Concept 2 – pillbox cavity - close aperture with thin conducting foil

- 805 MHz Cavity built & tested
- Surface fields 53 MV/m achieved
- Large dark currents observed
- Breakdown damage at highest gradients
- Lots of ideas for improvement

- 805 MHz Cavity built & being  tested

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## Neutrino Factory : Cooling Channel

**Neutrino Factory : Cooling Channel**

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## Construction of FODO Quad Cooling Cell

**             **
**             ****1/2                                                                           1/2****   **
**             ****abs****     ****F****        ****rf ****      ****D****       ****rf ****       ****F****       ****rf **** ****       ****D****    ****abs**
**COOLING CELL PHYSICAL PARAMETERS:**
**	****Quad Length****	****	****0.6 m**
**	****Quad bore****	****	****0.6 m**
**	****Poletip Field****	****	****~1 T**
**	****Interquad space****	****	****0.4 - 0.5 m**
**	****Absorber length****	****	****0.35 m ***
**	****RF cavity length****	****	****0.4 - 0.7 m***
**	****Total cooling cell length****	****4 m**
***The absorber and the rf cavity can be made longer if allowed to extend into the ends of the magnets.  **
**Or, more rf can be added by inserting another FODO cell between absorbers**
**In this design**
**                  ****For applications further upstream at larger emittances, this channel can support a 0.8 m bore, 0.8 m long quadrupole with no intervening drift without matching to the channel described here.**

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## MOVIE
Quad cooling movie / Kyoko Makino
GSview - View – fit window – full screen – page down - escape

**Quad cooling movie / Kyoko Makino**
**GSview - View – fit window – full screen – page down - escape**

- Quad Cooling Beam Dynamics Group
- UIUC – Debbie Errede, Kyoko Makino, Kevin Paul
- MSU – Martin Berz
- FERMILAB – Carol Johnstone, A. Van Ginneken

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## Recirculating Linear Accelerators (RLAs)

**Recirculating Linear Accelerators (RLAs)**

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## Recirculating Linear Accelerators (RLAs) :

**Recirculating Linear Accelerators (RLAs) :**
**Preaccelerator**

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## Recirculating Linear Accelerators (RLAs) :

**Recirculating Linear Accelerators (RLAs) :**
**Preaccelerator**

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## Recirculating Linear Accelerators (RLAs) :

**Recirculating Linear Accelerators (RLAs) :**
**Preaccelerator**

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## Recirculating Linear Accelerators (RLAs) :

**Recirculating Linear Accelerators (RLAs) :**
**Preaccelerator**

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## Recirculating Linear Accelerators (RLAs) :

**Recirculating Linear Accelerators (RLAs) :**
**Preaccelerator**

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## Recirculating Linear Accelerators (RLAs) :

**Recirculating Linear Accelerators (RLAs) :**
**Preaccelerator**

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## Recirculating Linear Accelerators (RLAs) :

**Recirculating Linear Accelerators (RLAs) :**
**Injection Chicane from Linac to RLA**

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## Recirculating Linear Accelerators (RLAs) :

**Recirculating Linear Accelerators (RLAs) :**
**Arcs**

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## Recirculating Linear Accelerators (RLAs) :

**Recirculating Linear Accelerators (RLAs) :**
**Arcs**

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## Slide 67

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## Recirculating Linear Accelerators (RLAs) 

**Recirculating Linear Accelerators (RLAs) **

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## Recirculating Linear Accelerators (RLAs) 

**Recirculating Linear Accelerators (RLAs) **

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## Muon Storage Ring

-  Maximize number of muon on production straight
-     **f****s**** = L****s****/C**
-  Minimize length of arcs
-         Real Estate is an important issue here.
-  Larger energy decreases angular beam spread (1/)
-   allowing more neutrinos on “target” = detector

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## Slide 71

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## Real Estate is an important issue here! : ARCS

**Real Estate is an important issue here! : ARCS**

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## COSY : Kyoko Makino (UIUC),   Martin Berz (MSU)

**COSY : Kyoko Makino ****(UIUC)****,   Martin Berz (MSU)**

- Tracking performed on a single arc cell.

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## COSY : Kyoko Makino (UIUC),   Martin Berz (MSU)

**COSY : Kyoko Makino ****(UIUC)****,   Martin Berz (MSU)**

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**Same Lattice with End Fields added**

## Slide 76

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## Conclusions

-   Neutrino physics is fascinating, beautiful and accessible.
-   A Muon Collaboration exists that has done two feasibility
-     studies on **neutrino factory** designs and R&D on targetry,
-     absorbers, 800 (200) MHz NCRF cavities, solenoid
-     magnets, and constructing a test area off of the Fermilab
-     400 MeV/c proton linac.
-     Design studies for Ring Coolers, FFAG machines,
-     Emittance Exchange are ongoing.
-   Alternative technologies pursued at CERN and in Japan.
-   Future plans include the construction of a cooling channel
-     lattice cell to be tested in a low intensity muon beam at
-     Rutherford Labs near Oxford, England.

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