RAL Muon Beam Line Properties

ISIS70 MeV H- injectionRing accelerates up to 800 MeV in about 10 ms

50 Hz cycle - Dual Harmonic System ~ 2 x 1.5 MHz; ~0.84

100 ns 100 ns230 ns

1.2 1013 protons

Rotation

Frequency

@800 MeV

Target Mechanism :

Coupled Oscillators:

50 Hz

150 HzTarget

Beam

Readout

2 ms

Target: 50 Hz + 150 Hz motione.g. equal amplitude:

20 ms

15 cm diam. (90%)

Beam: width 15cm contains ~1013 protons

Target: Ti 8×1 mm2. Intercepts 1‰ by area ~ 3×109 protons.

Limit by temperature: ~108

protons at 50 Hz.

Max possible intercepted beam

During the 2 ms, with the beam rotating at ~ 1.5 MHzthe beam circulates ~ 3x103 times

During 100 s of active RF; beam circulates 150 times

0

400

800

1200

1600

0 200 400 600 800

pi+

pi-

MeV/c

Rel

ativ

e F

lux

Particle Production (800 MeV)

LAHET calculations

Scattering Angle & Momentum:

50o

30o

40o

800 MeVprotonbeam

40o

30o

50o

Initial p

“Backwards” going muon

p locus,lab frame

p locus, rest frame

Largest difference between pion and muon momenta comes from backward going muons.

Relative + (and + bgd) as a fn of the initial and final momentum selection

300 MeV/c +

P+ MeV/c

P+ MeV/c

200 MeV/c +

Note: D2 is fixed to the momentum of the muon. The transmission of and is plotted as a fn of the pion momentum selected by D1.

+

+

D1

D2

Solenoid

Suggested Beam Line Layout (schematic)

Early questions to be addressed:

- modifications to target box ?- how close in can the beam line be ?- position and size of breach in wall ?

- do better without any quads?

Type II Dipole Magnet 55 degree bend0.863 T field (1.58 T max)

-0.25

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0.25

-0.15 -0.1 -0.05 0 0.05 0.1 0.15

X (m)

Xp

(r)

-0.25

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0.25

-0.15 -0.1 -0.05 0 0.05 0.1 0.15

Y (m)

Yp

(r)

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

-0.15 -0.1 -0.05 0 0.05 0.1 0.15

X (m)

Y (

m)

0

50

100

150

200

250

300

350

400

450

-0.2 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 0.2

Y (m)

N(Y

)

0

100

200

300

400

500

600

-0.2 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 0.2

X (m)

N(X

)

Estimate ~7,500 muons in a 100 s burstevery 20 ms.

What is the maximummuon rate?