Cooling Experiment Simulations in Europeagni.phys.iit.edu/~capp/workshops/mumice02/talks/Hanke.pdfMICE Collaboration Meeting – Feb 8, 2002 - IIT K.Hanke Cooling Experiment Simulations

MICE Collaboration Meeting – Feb 8, 2002 - IIT K.Hanke

Cooling Experiment Simulationsin Europe

K.Hanke CERN

Collaboraton with INFN/Frascati


88 MHz option- possible scenarios: 8 cavities and 4 cavities - hardware design and simulation results

a) scenario using 8 cavities- beam dynamics (PATH)- cross check with ICOOL- parameter scan

b) scenario using 4 cavities- beam dynamics and parameter scan

200 MHz option- simulation results (INFN collaboration)


88 MHz Option: Lay-Out

8 cav/sol

input diagnostics(sol. lattice ctd.)

output diagnostics(sol. lattice ctd.)solenoids of 45 cmlength with 15 cm spacing

entry absorber (47 cm LH) exit absorber (47 cm LH)

cooling

4 cav/sol

input diagnostics output diagnostics

entry absorber (23.5 cm LH) exit absorber (23.5 cm LH)

cooling

a)

b)


88 MHz Cavities

beam tube 15 cm

90 cm unit length

84 cm

37 cm

beam axisconnection between units

SC solenoid SC solenoid

15 cm: mounting & solenoid supply

88 MHz cavities for muon coolingSuperFish design, F.Gerigk


Solenoids for the 88 MHz Cavities

solenoids designed according to boundary conditions imposed by cavitiestake into account cryogenics, forces etc.

maximum Bz on axis: quench limit for NbTi at 4.5 K: 9 T

4.5 T if at 60% on load line 6.0 T if at 80% on load linepresent settings stay well below 4.5 T1200 1300 1400 1500 1600 1700 1800 1900 2000

-2

-1

0

1

2

3

4

5

1200 1300 1400 1500 1600 1700 1800 1900 2000

-2

-1

0

1

2

3

4

5

ROXIE8.2

500 700 900 1100 1300 1500 1700 1900 2100 2300 2500 2700ROXIE8.1


88 MHz Option (8 Cav.): Beam Dynamics

typical input beam parameters:input energy: 200 MeV (variable)energy spread +- 15 MeV� = 0, ��= 1 m, ��variable

settings of the channel:solenoid settings: ~ 3 Tcavity phase: 0 deg

kinetic energy vs z for 88 MHz cooling experiment (8 cav.) computed with PATH

1.85E-01

1.90E-01

1.95E-01

2.00E-01

2.05E-01

2.10E-01

2.15E-01

2.20E-01

0 2 4 6 8 10 12 14 16

z [m]

kin

eti

c e

ne

rgy

[Ge

V]



transv. emittance (r.m.s., norm.) vs z for 88 MHz cooling experiment (8 cav.) computed with PATH (50.000 particles)performance for example optics:transv. emittance reduction: - 3.7% particle gain in acceptance: + 9.1 %

4.70E-03

4.75E-03

4.80E-03

4.85E-03

4.90E-03

4.95E-03

0 2 4 6 8 10 12 14 16

z [m]

tra

nsv

ers

e e

mit

tan

ce [

m r

ad

]



have recently included in the simulations:

-absorber windows (150 �m): essentially no effect

-field flip:does not change cooling performance

new


Cross-Check of PATH vs ICOOL

for the same input beam (50.000 particles) and the same channel optics, the results could be reproduced in ICOOL

transv. emittance (r.m.s., norm.) vs z for 88 MHz cooling experiment (8 cav.) computed with ICOOL (50.000 particles)

4.70E-03

4.75E-03

4.80E-03

4.85E-03

4.90E-03

4.95E-03

0 2 4 6 8 10 12 14 16z [m]

tran

sve

rse

em

itta

nce

[m

rad

]



x - emittance (r.m.s., norm.) vs z for 88 MHz cooling experiment (8 cav.)computed with PATH and ICOOL (50.000 particles)

4.70E-03

4.75E-03

4.80E-03

4.85E-03

4.90E-03

4.95E-03

0 2 4 6 8 10 12 14 16

z [m]

x e

mit

tan

ce [

m r

ad

]

ICOOL

PATH



y - emittance (r.m.s., norm.) vs z for 88 MHz cooling experiment (8 cav.)computed with PATH and ICOOL (50.000 particles)

4.70E-03

4.75E-03

4.80E-03

4.85E-03

4.90E-03

4.95E-03

0 2 4 6 8 10 12 14 16

z [m]

y e

mit

tan

ce [

m r

ad]

ICOOL

PATH


Cross-Check of PATH vs ICOOL: Conclusion

simulations started from the same input distribution,used the same set-up, optics and field maps

PATH ICOOLtransmission 100 % 100 %

transv. emittance -3.7 % -3.2 %reduction

particle gainin acceptance +9.1 % + 7.6 %(1.5 cm rad norm.and 0.1 eVs)

both runs done with same input distribution (50.000 particles)


88 MHz Option (8 Cav.): Parameter Scan

output emittance vs input emittance (r.m.s., norm.)

transmission vs inputemittance(r.m.s., norm.)

1500

3000

4500

6000

7500

1500 3500 5500 7500 9500

input emittance [mm mrad]

ou

tpu

t e

mit

tan

ce [

mm

mra

d]

Ei=200 MeV

85

90

95

100

105

1500 2500 3500 4500 5500 6500 7500 8500 9500


tran

smis

sio

n [

%]

Ei=200 MeV

8 cavities, E = 200 MeV


cooling efficiency is measured as number of muons insidean acceptance of 0.1 eVs and 1.5 pi cm rad (norm.)

depending on input emittance, cooling efficiency up to 15%


-10

-5

0

5

10

15

20

1500 2500 3500 4500 5500 6500 7500 8500 9500


coo

ling

pe

rfo

rman

ce [

%]

in 6

D

Ei=200 MeV



-15

-10

-5

0

5

10

15

20

1500 3500 5500 7500 9500

coo

ling

pe

rfo

rman

ce in

6D

[%

]

200 MeV

170 MeV

230 MeV

140 MeV


cooling efficiency for various input beam energies



various input beam energies used:230, 200, 170, 140 MeV (kinetic)for each energy: eout vs ein, cooling efficiency, transmissionsee NF Note 90for lower energy, the cooling performance goes up

Ein [MeV] coolingefficiency[%]

solenoidfield [T]

230 7.5 2.7

200 10.0 2.7

170 11.5 2.7

140 12.5 2.7

comparison of coolingefficiency for ein = 5500mm mrad and various input beam energies



cooling performance of a system with only 4 cavities (50.000 particles)performance for example optics:transv. emittance reduction 2%particle gain in acceptance: +3.5 %performance drops down roughly in proportion

4.70E-03

4.75E-03

4.80E-03

4.85E-03

4.90E-03

4.95E-03

0 2 4 6 8 10 12 14 16

z [m]

tran

sve

rse

em

itta

nce

[m

rad

]


1500

3500

5500

7500

9500

1500 3500 5500 7500 9500 11500


ou

tpu

t e

mit

tan

ce [

mm

mra

d]

Ei=200 MeV

80

85

90

95

100

105

1500 3500 5500 7500 9500 11500


tran

smis

sio

n [

%]

Ei=200 MeV


4 cavities, E = 200 MeV

output emittance vs input emittance (r.m.s., norm.)

transmission vs inputemittance(r.m.s., norm.)


cooling efficiency is measured as number of muons insidean acceptance of 0.1 eVs and 1.5 pi cm rad (norm.)

depending on input emittance, cooling efficiency up to 10%


-10

-5

0

5

10

15

20

1500 3500 5500 7500 9500 11500


coo

ling

pe

rfo

rman

ce in

6D

[%

]

Ei=200 MeV



input energies used: 200 MeV and 140 MeV (kinetic)the hope is to compensate reduced cooling performance by goingto lower energy

Ein [MeV] coolingefficiency [%]

solenoidfield [T]

200 4.5 2.7140 6.5 2.5

comparison of cooling efficiency for ein = 5000 mm mrad andtwo different input beam energies


200 MHz Simulations at INFN Frascati

Michele CastellanoLuciano CataniAlessandro CianchiMassimo FerrarioValeria FuscoMauro MiglioratiLuigi PalumboBruno SpataroFranco TazzioliCristina VaccarezzaVictor Verzilov

Collaboration with NFWG at CERN

Aim:Design a Test Facility for �-cooling Prepare a proposal by the end of June 2002

Task of INFN group: Study the 200 MHz scheme in comparison with the 88 MHz scheme proposed at CERN


diagnostic solenoids ~2m

4 RF 200MHz cells, 7.6 MV/m

2 absorbers of 46 cm LH

kinetic energy: � 200 MeV

emittance (rms, norm.):� 3 – 10 mm rad

Components & Parameters


200 MHz Option: Simulation Results

0

1 104

2 104

3 104

4 104

5 104

6 104

-200 0 200 400 600 800 1000 1200

B field on axis

Bz

(G)

z (cm)

0,0045

0,005

0,0055

0,006

0,0065

0,007

0 2 4 6 8 10

AbsorbersNo Absorbers

Tra

nsve

rse

rms

norm

aliz

ed e

mitt

ance

[m r

ad]

z [m]

PATH simulation of 2 × 2 cell 200 MHz cavity with 2 × 46 cm LH absorber

particle gain in acceptance:+ 9%as in 88 MHz case


Conclusion

a cooling experiment, which is a subsection of the CERN88 MHz cooling channel, has been simulated with PATH basedon engineering designs for cavities and solenoids

the cooling performance is about 3.7 % in transverse(r.m.s) emittance reduction and about 9.1 % increase of muons inside the RLA acceptance (for nominal optics)the performance of a system of only 4 cavities drops down in proportion

the results have been confirmed with a second code (ICOOL)

a detailed parameter scan has been performed to evaluate the per-formance of the channel for various input beams, settings etc.(E.-S.Kim, K.Hanke, NF Note 90)

a 200 MHz system has been simulated and shows a cooling performancecomparable to the 88 MHz option

Summary paper in preparation

Documents

Cooling Experiment Simulations in Europeagni.phys.iit.edu/~capp/workshops/mumice02/talks/Hanke.pdfMICE Collaboration Meeting – Feb 8, 2002 - IIT K.Hanke Cooling Experiment Simulations