comments on target solenoid optimization manuscript

COMMENTS ON TARGET SOLENOID OPTIMIZATION MANUSCRIPT

HISHAM SAYEDBROOKHAVEN NATIONAL LABORATORY

Target group meeting 10/10/2013

Target group meeting 10/10/2013

FE BUNCHER & PHASE ROTATOR CELL

Target group meeting 10/10/2013

ACCEPTANCE IN LONGITUDINAL PHASE SPACE

Long. Phase space at z=0

Initial scan points

Scusseful points

Initial homogenous distribution in t-pz phasespace at the target location (z=0 m )

Target group meeting 10/10/2013

ACCEPTANCE IN LONGITUDINAL PHASE SPACE

Long. Phase space at z=50

Initial scan points

Scusseful points

Initial homogenous distribution in t-pz phasespace before the first RF cavity in the buncher location (z=50 m)

Initial time 20 ns width and pz from 0-1 GeV/c. (2.5E5 particles through the front end) Acceptance windows are limited to

~ 5 nsec time width limit for each bunch (if we assume Gaussian distribution 1 sigma ~ 1.6 ns).

mom. spread of ~ 70 MeV/c (if we assume a Gaussian distribution 1 sigma is ~ 23 MeV/c & dp/p ~ 0.07-0.1)

Δt~ 5 ns

Δp~ 70 MeV/c

Target group meeting 10/10/2013

PHASE SPACE DISTRIBUTIONS (SHORT VERSUS LONG TAPER)

Short Taper 4 mLong Taper 40 m

Longitudinal phase space at end of decay channel

The average time spread for the long taper is ~ 20 ns while for short one it is ~ 10 ns with higher core density in case of the short taper.

Target group meeting 10/10/2013

DEPENDENCE OF TIME SPREAD & TRANSVERSE EMITTANCE ON TAPER LENGTH

Transverse emittance decreases by 8% with solenoid taper length going 840 m

Time Spread increase by 90% with solenoid taper length going 840 m

Transverse emittance shaped by capture solenoid

Time spread shaped by capture solenoid

Target group meeting 10/10/2013

MUON COUNT WITHIN ENERGY CUT AT END OF DECAY CHANNEL

MARS1510 Simulation:Counting muons at 50 m with K.E. 80-140 MeV

Muon count at z=50 increases for longer solenoid taper

Target group meeting 10/10/2013

FRONT END PERFORMANCE

High statistics tracking of Muons through the front end

μ+ o

nly

Baseline

Target group meeting 10/10/2013

DEPENDENCE OF TRANSVERSE EMITTANCE & CAPTURE EFFICIENCY ON PEAK FILED

Transverse rms emittance doubles as peak field decreases from 50 T 20 T

Transverse emittance shaped by capture solenoid peak field

B(at target)=5010 T

Target group meeting 10/10/2013

DEPENDENCE OF TRANSVERSE EMITTANCE & CAPTURE EFFICIENCY ON PEAK FILED

Target group meeting 10/10/2013

DEPENDENCE OF TRANSVERSE EMITTANCE & CAPTURE EFFICIENCY ON PEAK FILED

Transverse emittance doubles as peak field decreases from 50 T 20 T

Number of pions+muons+k within transverse 6 σ cut and Pz=0.0-1.0 GeV/c

Transverse emittance shaped by capture solenoid

Capture efficiency dependence of peak solenoid field z=0.0

N(π

+)

Target group meeting 10/10/2013

MUON YIELD VERSUS END FIELD INCLUDING OPTIMIZATION OF FE

Muon yield versus end field

Impact of transverse focusing field on performance of FE:Constant solenoid filed in Decay Channel – Buncher – Rotator (matched to +/- 2.8 T ionization cooling channel)

Baseline

Bz(Target)=20 T

20% for every 1 T increase in constant field

60% more than baseline performance

Target group meeting 10/10/2013

STORED ENERGY

Stored energy versus end field for one magnet

U [J] = (π/2μ0)(B2 R2) L

FE Constant field magent (Weggel)

B[z]

Z [m]

Magnet Length [m] Inner R [m] Outer R [m] J [A/mm2]

1 0.19 0.6 0.68 47.18

2 3.8 0.6 0.63 40.00

3 0.19 0.6 0.68 47.18