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S P r in g 8 Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JAS RI S P r in g 8 LEPS Collab. Meeting Academia Sinica, Jan. 13, 2006
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Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

Dec 31, 2015

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Page 1: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8

Possible further extensions in thenew LEPS beamline in Spring-8

S. Daté Accelerator Division, SPring-8/JASRI

S P r i n g8

LEPS Collab. MeetingAcademia Sinica, Jan. 13, 2006

Page 2: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8Contents

1. Introduction2. A short summary of previous discussions on energy u

pgrade above 5 GeV 3. A new estimate of high energy gamma yield for X-ray r

e-injection scheme4. Conclusion

Page 3: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8§1. Introduction

LEPS experiments have proved the accessibility to new frontiersin hadron physics by making use of its advantages in measuring the forward angular regions without harmful background noise and manipulating gamma ray characteristics through easy-to-access laser system. They also enjoy highly stable operation of Spring-8 accelerators and its low emittance electron beams. After 5 years of physics runs with several important outputs, we are in a position to discuss a new LEPS beamline with enhancement and emphasis of recognized advantages, supplements to weak points, and challenges to completely new possibilities, which all motivated by physics.

Page 4: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8

SPring-8 Beamline Map

Page 5: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8Directions of extentions

Energy -> 3.5 GeV in near future (Laser upgrade) ~> 4 - 6 GeV ?Intensity -> 107-8/s (high power laser, LRNB, high current, round beam, new tagging system)Detector Polarized target

Page 6: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8High Energy Backward Compton Photons

Page 7: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8HELP production by X-ray re-injection

Page 8: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8HLEP generation by X-ray re-injection (2)

8 GeV 100 mA SR

Undulator

X-ray mirrorReflectivity = 0.810 = 10%

Ex =100 eV

E< 7.4 GeV

Diamond mirror

Page 9: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8Multilayer Reflectivity

Page 10: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8A short summary of previous discussions

X-ray generation reflection & re-injection gamma ray production

Gamma yield =

˙ N γ = 2Ie

e

σl

csR ˙ N ph = 4.16 ×10−12 Ie[A]

l[m]

s [mm2]Rσ [b] ˙ N ph

d ˙ N ph

dωdΩ= αγ 2N 2 I

e

1

ωFk (K, γθ, φ;ω /ω1)

k=1

α I

e= 4.55 ×1016 (s−1) I[A]

˙ N ph ≈4 ×1017 /s (100mA, N = 30)

˙ N γ ≈ 2 ×104 /s×l[m]

s[mm2]R

Page 11: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8

Cross section depends on photon energy

˙ N γ = 2Ie

e

l

csx

R ˙ I = 4.16 ×10−12 Ie[A]l[m]

sx[mm2]

R ˙ I

1 barn

d ˙ I

dEγ

= dωdσ

dEγ

(ω)ω1

ω2∫d ˙ N ph

d˙ I dE/ I

e ,

Page 12: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8Re-focussing

Thin undulator approximation

e-

275x2 m

6x2 m

~100 rad

Can s be

5×10−3mm2 ?

In principle, yes.

spherical mirror

Page 13: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8Bunch mode dominance

. . .100 rad

60 cm

h ~ 275 m

e-

v ~ 6 m

60cm/2 ×100μrad = 30μm

Nγnext ~

σ

aph

~Nγ

main

5

Nγall ~ 1.75Nγ

main

Page 14: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8

Bunch-bunch collisions

˙ N γ =ne / b( )

2

sfbRI 1

I 1 = ˙ I Ie

e

=10−2 b (K = 5 ~ 6, Eγ = 4 - 6 GeV)

s = 0.5 ×10−2 mm2

ne / b fb =Ie

e

Limit: Heat load at finger contact ~

ne / b( )2

fb

Maximum: 174 bunch filling

˙ N γ = 2 ×106 /s × R

Page 15: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8Conclusion

Providedan undulator with high reflectable (R > 0.1)spherical mirror for 100 eV photonswith timing adjustment system (mirror position z = 24 +- 2 m, dz = 6mm)

N p = 4, λ 0 =1.1m, B0 = 300 kG − 600kG

We may obtain

˙ N γ = 2 ×105 /s

in principle.

Page 16: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8*******LEPS/SP8 template******

Page 17: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8*******LEPS/SP8 template******

Page 18: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8*******LEPS/SP8 template******

Page 19: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8*******Suppl******

(2)

˙ N γ = ne / b( )2 fb

sx

I 1

=Ie

eI 1

˙ N γ = 2I

e

σ l

csx

˙ N ph = 4.5 ×10−14 l[m]

sx[mm2]˙ N ph

Page 20: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8HELP generation (3)

Page 21: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8Primakov Production of

Page 22: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8Radiation formula

d ˙ N ph

dωdΩ= αγ 2N 2 I

e

1

ωFk (K, γθ, φ;ω /ω1)

k=1

α I

e= 4.55 ×1016 (s−1) I[A]

Page 23: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8Conclusion in the meeting on Oct. 20, 2005

The maximum yield of gamma in 5~6 GeV region attainable

in Spring-8 SR:

2 ×104 /s×l[m]

s[mm2]

in an 1A, 1.5 GeV SR:

3 ×105 /s×l[m]

s[mm2]

K = 3, λ 0 =1.1 m

K = 2.56, λ 0 = 5 cm

=>

=>

Page 24: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8Cross section convoluted with Nph

d˙ I dE

/ R/ I

e ,

d ˙ I

dEγ

= R dωdσ

dEγ

(ω)ω1

ω2∫d ˙ N ph

Page 25: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8An undulator to produce 100 eV photons

Matching of the first harmonics:

K = 0.934 × B0[T]λ 0[cm]

100 eV = ω1(0) =4πβhcγ 2 /λ 0

1+ K 2 /2

λ0 <1 m

K = 3

λ0 =1.1 m

B0 = 300 kG

K > 2

Page 26: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8Yield of X-ray photons

d˙ N ph

d / I

e( 

      

      

      

      

      

      

)

Page 27: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8Compton cross section

Page 28: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8Reflectivity of N=11 multilayer mirror

Page 29: Possible further extensions in the new LEPS beamline in Spring-8 S. Daté Accelerator Division, SPring-8/JASRI LEPS Collab. Meeting Academia Sinica, Jan.

S P r i n g8 Physics @workshop

Exotics: +, (1405), S11(1535) ---- 5q X(K-bound), C(1480) ---- 4q glueball, hybrid, odderon(odd-glueball) --- multi-g(+qq) Dirac monopole High precision: hyperon photoproduction nucleon resonance (e.g. pol +p 0 + p_pol ) A-dependence – mean free path nonmesonic decay of hypernucleus Compton scattering – nucleon swelling 0, –lifetime, polarizability, Primakoff (high E, forward) Others: J/ from d or A (c.f. Eth(+p J/ +p)=8.1 GeV) CP violation ()GDH polarized HD target