Proceedings of the 5th Annual Meeting of Particle Accelerator Society of Japanand the 33rd Linear Accelerator Meeting in Japan (August 6-8, 2008, Higashihiroshima, Japan)

EMITTANCE REDUCTION OF ELECTRON STORAGE RING BYLONGITUDINALLY AND RADIALLY VARYING DIPOLE FIELD
Koji Tsumaki
JASRI/SPring-8
1-1-1 kouto,Sayo, Hyogo, 679-5198
Abstract
It is important to improve the emittance of existing storage ring at lower cost and with smaller change. We studied
the emittance reduction by longitudinally and radially varying dipole field, which has the possibility of satisfying thesecondition. We found that the emittance reduces to about 1/5 by this method. We applied it to the SPring-8 storage ring.
The emittance was 1.68 nm without dispersion function at straight section and 0.63 nm with 0.06 m dispersion function.
This shows this method is effective for improving the emittance of existing storage ring.

㛏 ᡥ᪁ྡྷ ࡛༖ᙼ ᪁ྡྷ࡞ ☚ሔ࠿ ን໩ࡊࡒ ೩ྡྷ㞹 ☚▴࡞ ࡻࡾ㞹 Ꮔ⵫✒ ࣛࣤࢡ ࡡ࢙࣐ ࢴࢰࣤ ࢪ఩΅࣭࢟ࡡ఩࠷ᨲᑏකࢅࠉฦᩋ㛭ᩐࡡᑚࡈ࡝࡛ࡆࢀ࡚☚ሔࢅᙁࡂࡊ࡙࢙ࢾ࣭ࣜ࢟ࡡ㧏࠷ᨲᑏකࢅฝࡌࡻ࠹࡞
ࡌࡿࡣࠉධమ࡛ࡊ࡙ທ㉫ࢅᑚࡈࡂ࡚ࡀࡾࠊ
㞹Ꮔࣄ࣭࣑ࡡ࢙࣐ࢴࢰࣤࢪࡢḗࡡࡻ࠹࡞⾪ࡎࡾࠊ㸦㸣ࡢࡋࡴ࡞

ᨲᑏකࣛࣤࢡ࡞࡛ࡖ࡙ࠉ㍜ᗐࡢ᭩ࡵ㔔さ࡝ࣂ࣒࣭ࣚࢰ࡚࠵ࡽࠉ㧏࠷࡮࡜Ⰳ࠷ࠊ㍜ᗐࡢ㞹Ꮔࣄ࣭࣑ࡡ
࢙࣐ࢴࢰࣤࢪ࡞㏣Ẓౚࡌࡾࡒࡴࠉ࢙࣐ࢴࢰࣤࢪ࠿ᑚ
3Cq# 02 H $ dsࡈ࠷࡮࡜Ⰳ࠷ࡆ࡛࡞࡝ࡾࠊᨲᑏකࣛࣤࢡࡡṌྍࡢ࢙" x0 =࣐ࢴࢰࣤࢪ఩΅ࡡṌྍ࡛ゕࡖ࡙ࡵ㐛ゕ࡚ࡢ࡝࠷ࠊ
Jx1 $ 2 ds㞹Ꮔ⵫✒ࣛࣤࢡහࡡ㞹Ꮔࣄ࣭࣑ࡡ࢙࣐ࢴࢰࣤࢪࡢࠉ
55 hᨲᑏකࡡᨲฝ࡞ࡻࡾທ㉫࡛ࠉ7+ຊ㏷࡞ࡻࡾࢱࣤࣅࣤ
Cq =[1]ࢡࡡ㔦ࡽྙ࠷࡞ࡻࡖ࡙Ửࡱࡾ ࠊࡐࡡࡒࡴ࢙࣐ࢴࢰ32 3 mcࣤࢪࢅᑚࡈࡂࡌࡾࡒࡴ࡞ࡢࠉທ㉫ࢅᑚࡈࡂࡌࡾ࠾ࠉ
# $ (1 $ 2 + 2B ' B$ )ds
ࢱࣤࣅࣤࢡࢅ㏷ࡂࡊ࡙ࡷࡿࡣⰃ࠷ࠊທ㉫ࢅᑛ࡝ࡂࡌ !
(1)
J x = 1"ࡾࡒࡴ࡞ࡢࠉᨲᑏකࢅⓆ⏍ࡈࡎࡾ೩ྡྷ㞹☚▴හ࡚࢙
1 $ 2 dsࢾ࣭ࣜ࢟ฦᩋ㛭ᩐࢅᑚࡈࡂࡌࡿࡣⰃ࠷ࠊ᭩ࡵ⠾༟࡝
!
H = "# 2 + 2$##'+%#'2 .
᪁Ἢࡢ೩ྡྷ㞹☚▴ࡡ೩ྡྷみࢅᑚࡈࡂࡊ࡙ฦᩋ㛭ᩐࢅᘟ㸝㸦㸞ࡻࡽࠉᐁ㝷ࡢฦᩋ㛭ᩐࡓࡄ࡚࡝ࡂࠉ࣭࣊
[2]ᢒ࠻ࡾ᪁Ἢ࡚࠵ࡾ ࠊ೩ྡྷみ࠿Ửࡱࡖ࡙ࡊࡱࡖ࡙࠷
ࢰࢹࣞࣤ㛭ᩐࢅྱࡳᡜㅕH㛭ᩐ࡛ᴗ⋙༖ᙼ࠽ࡻࡦJxࡾሔྙ࡞ࡢࠉ㛏ᡥ᪁ྡྷ࡞☚ሔᙁᗐࢅን໩ࡈࡎ࡙ທ㉫࡚࢙࣐ࢴࢰࣤࢪ࠿Ửࡱࡾࡆ࡛ࢅ♟ࡊ࡙࠷ࡾࠊJxࡢ☚[3][4][5]ࢅᑚࡈࡂࡌࡾ᪁Ἢ࠿࠵ࡾ
ࠊࡱࡒࢱࣤࣅࣤࢡࢅ㏷ !
ሔ໖㒼࠿࡝࠷ሔྙ࡮࡛ࢆ࡜㸦࡚ࠉㇿࡡ☚ሔ໖㒼࠿࠵!
ࡂࡌࡾࡒࡴࡡ᪁Ἢ࡛ࡊ࡙೩ྡྷ㞹☚▴ࡡ༖ᙼ᪁ྡྷ࡞☚ࡾሔྙ㸦ࡻࡽኬࡀࡂ࡝ࡽ࢙࣐ࢴࢰࣤࢪࡢᑚࡈࡂ࡝ࡾࠊ
[1]ሔ໖㒼ࢅࡗࡄࡾ᪁Ἢ࠿࠵ࡾ ࠊ᩺ࡒ࡞⵫✒ࣛࣤࢡࢅᘋスࡌࡾሔྙࡢࠉ೩ྡྷみࢅᑚ㸨㸣㛏ᡥ᪁ྡྷ࡛༖ᙼ᪁ྡྷ࡞ን໩ࡌࡾ☚ሔ࡞ࡈࡂࡊ࡙࢙࣐ࢴࢰࣤࢪࢅ㏛ịࡌࡾ᪁Ἢ࠿࠵ࡾ࠿ࠉ᪜Ꮛࡡࣛࣤࢡࡡୌ㒂ࢅᨭⰃࡊ࡙࢙࣐ࢴࢰࣤࢪࢅᑚࡈࡂࡻࡾ࢙࣐ࢴࢰࣤࢪࡊ࡝ࡄࡿࡣ࡝ࡼ࡝࠷ሔྙࡷࠉ⤊ῥⓏ࡝⌦⏜࡝࡜࡚೩ᅒ㸦࡞85ULQJ⵫✒ࣛࣤࢡࡡ೩ྡྷ㞹☚▴࡞ᑊࡌࡾྡྷみ࠿Ửࡱࡖ࡙࠷ࡾሔྙ࡞ࡢࡆࡡ᪁Ἢ࠿㐲⏕࡚ࡀ࡝- 㛭 ᩐ ࢅ ࠉ ᭩ ᑚ ࢙ ࣐ ࢴ ࢰ ࣤ ࢪ 2LQLPXP࠷ࠊࡐࡆ࡚೩ྡྷみ࠿Ửࡱࡖ࡙ࡊࡱࡖ࡙࠷ࡾሔྙࡡ࢙
*PLWWFQHH 2* ࡡ ሔ ྙ ࡛ ├ ⥲ 㒂 ࠿ ↋ ฦ ᩋ 2LQLPXP࣐ࢴࢰࣤࢪ఩΅Ἢ࡛ࡊ࡙ࠉ೩ྡྷ㞹☚▴ࡡ☚ሔࢅ㛏ᡥ*PLWWFQHH&HKURPFW 2*& ࡡሔྙ࡞ࡗ࠷࡙♟ࡌࠊ᪁ྡྷ࡛༖ᙼ᪁ྡྷ࡞ን࠻ࡾ᪁Ἢࢅ᳠ゞࡊࡒࠊࡐࡡ⤎ᯕ
0.004
ࢅSPring-8⵫✒ࣛࣤࢡ࡞㐲⏕ࡊࠉ೩ྡྷ㞹☚▴ࡡࡲཱི
0.003ࡽ᭨࠻࡙࢙࣐ࢴࢰࣤࢪ࠿࡜ࡡ⛤ᗐࡱ࡚ᑚࡈࡂ࡚ࡀࡾ࠾᳠ゞࡊࡒࠊ
0.002

%%%

H (!)

%MEA㸧㸣⵫✒ࣛࣤࢡࡡ࢙࣐ࢴࢰࣤࢪ

0.001

 ೩ྡྷ㞹☚▴ࡡ☚ሔ࠿ୌᏽࡡሔྙᨲᑏකࡡ࢙ࢾ࣭ࣜ࢟ࢪ࣋ࢠࢹࣜࡢ☚▴හ࡚ྜྷࡋ࡚࠵ࡾࠊࡊ࠾ࡊࠉฦᩋ㛭ᩐࡡኬࡀ࡝࡛ࡆࢀ࡚☚ሔᙁᗐࢅᘽࡂࡊ࡙࢙ࢾࣜ

ME
0

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08! (rad)ᅒ㸦㸯85ULQJ⵫✒ࣛࣤࢡ೩ྡྷ㞹☚▴ࡡ-㛭ᩐࠊ-108-

Proceedings of the 5th Annual Meeting of Particle Accelerator Society of Japanand the 33rd Linear Accelerator Meeting in Japan (August 6-8, 2008, Higashihiroshima, Japan)ࡆࡿࡻࡽ᭩ᑚ࢙࣐ࢴࢰࣤࢪࡡሔྙࡢࠉ೩ྡྷ㞹☚▴ࡡ୦ഁ࡚ᴗ⋙༖ᙼࢅኬࡀࡂ㸝☚ሔᙁᗐࢅᘽࡂ㸞ࠉ୯ኳ࡚ᑚࡈࡂ㸝☚ሔᙁᗐࢅᙁࡂ㸞ࡌࡿࡣࡻ࠷ࡆ࡛࠿ࢂ࠾ࡾࠊ├⥲㒂࠿↋ฦᩋࡡሔྙࡢࠉ↋ฦᩋࡡථࡽཾഁ࡚ᴗ⋙༖ᙼࢅᑚࡈࡂ㸝☚ሔᙁᗐࢅᙁࡂ㸞ࠉฝཾഁ࡚ኬࡀࡂ㸝☚ሔᙁᗐࢅᘽࡂ㸞ࡌࡿࡣࡻ࠷ࡆ࡛࠿ࢂ࠾ࡾࠊࡆࡡࡆ࡛࠾ࡼࠉᴗ⋙༖ᙼ࡛ࡊ࡙ḗᘟ࡚⾪ࡈࡿࡾኣ㡧ᘟࢅ᤿⏕ࡊࡒࠊn    " = " a s # s0 + " 0          (2)! (K=-1.5)/! (K=0)

10.5
2 GeV
6 GeV
012

B

34/B

max 0
ࡒࡓࡊࠉ↋ฦᩋࡡሔྙS0 = 0 ࠉ᭩ᑚ࢙࣐ࢴࢰࣤࢪࡡᅒ㸨㸯༖ᙼ᪁ྡྷࡡ☚ሔ࠿࠵ࡾሔྙࡡ࢙࣐ࢴࢰࣤࢪ΅
ሔྙࠉS0 = Lm/2㸝Lmࡢ☚▴ࡡ㛏ࡈ㸞ࠊ࢙࣐ࢴࢰࣤࢪ
ᑛ⋙ࡡ᭩ኬ☚ሔ౪Ꮛᛮࠊ
!ࡡゝ⟤ࡢࠉᩐೋゝ⟤࡚⾔ࡖࡒࠊᩐೋゝ⟤ࢅ⾔࠹࡞ࡢ 
රమⓏ࡝ࣂ࣒࣭ࣚࢰ࠿ᚪさ࡚࠵ࡾࠊࡐࡆ࡚ࠉኬᆵ࣏ࢨࣤࢅ௥⾪ࡊ࡙ࠉ࢙ࢾ࣭ࣜ࢟6 GeV,೩ྡྷ㞹☚▴ᩐ88ࠉ ࢢ࣭ࣛࣤࢡ࡚ࡀࡾࡆ࡛࠿ࢂ࠾ࡾࠊ࡛ࡆࢀ࠿༖ᙼ᪁ྡྷᖲᆍ☚ሔᙁᗐ0.5 Tࡡࡵࡡ࡛ࠉ୯ᑚᆵ࣏ࢨࣤࢅ௥⾪ࡊࡡ☚ሔ໖㒼࠿࠵ࡾሔྙࡢࠉ㸧,H;ࡡሔྙࡻࡽ㸫,H;ࡡ
࡙ࠉ࢙ࢾ࣭ࣜ࢟2 GeV,೩ྡྷ㞹☚▴ᩐ24ࠉᖲᆍ☚ሔᙁ࢙࣐ࢴࢰࣤࢪࡡ΅ᑛࡡ⛤ᗐ࠿ᑛ࡝ࡂࠉ᭩ኬ☚ሔ࠿ኬᗐ1.5 Tࡡࡵࡡࢅཱིࡽ୕ࡅࡒࠊ୦⩽ࡢ࡝ࡾ࡬ࡂࣂࣚࡀࡂ࡝ࡾ࡞ࡗࡿᕣࡢ㢟ⴥ࡞࡝ࡾࠊࡆࡿࡼࡢࠉ'PF]"'࣒࣭ࢰ࠿㞫ࡿࡾࡻ࠹࡞ࡊࡒࠊࡱࡒ༖ᙼ᪁ྡྷࡡ☚ሔࡡࡡ᫤ࡡ࢙࣐ࢴࢰࣤࢪࡡ΅ᑛ࠿ࠉ㸫,H;࡚ኬࡀࡂࠉ㸧ലࡀKࡢࠉ㸥࡛-1.5 m-2 ࡛ࡊࡒࠊ௧୕ࡡ᮪௲࡚࢙࣐ࢴ,H;࡚ᑚࡈ࠷ࡒࡴ࡚࠵ࡾࠊࡆࡡࡻ࠹࡞༖ᙼ᪁ྡྷ࡞☚ࢰࣤࢪ࡛᭩ኬ☚ሔࡡ㛭౿ࢅịࡴࡒࠊMEࡡ᮪௲࡚ࠉnሔ໖㒼࠿࠵ࡾሔྙࡢࠉ'PF]' ࡚ࢪࢢ࣭ࣛࣤࢡ࡚ࡀ࡝࠿㸧ࡡሔྙ࡞ࡗ࠷࡙ゝ⟤ࡊࡒ⤎ᯕࢅᅒ㸧࡞♟ࡌࠊ
࠷ࠊ

1
1
2.5

0.5

K=016 GeV
2 GeV

00.3

K = -1.5

0.5!/!

1.5

00.4!!!

2

0.5

0.2

0.1

0.5

006 GeV
2 GeV

6 GeV K = 06 GeV K = -1.5! (nm)! (nm)

2 GeV K = 02 GeV K = -1.5

1234B

(T)

max

5600.5

1

1.5B

max

(T)

2123B

/B

40123B4/Bᅒ㸩㸯ぞ᰹໩ࡈࡿࡒ࢙࣐ࢴࢰࣤࢪࡡぞ᰹໩ࡈࡿࡒ᭩ኬ☚ሔ౪Ꮛᛮࠊmax

0max

0

 F ,H; G ,H;
ᅒ㸧㸯᭩ኬ☚ሔᙁᗐࢅን໩ࡈࡎࡒ᫤ࡡ࢙࣐ࢴࢰࣤࢪࡡን໩ࠊ㸩㸣SPring-8⵫✒ࣛࣤࢡ࡫ࡡᚺ⏕ 0㸲㸥ࡡ࡛ࡀ࢙࣐ࢴࢰࣤࢪࡢᣞᩐ㛭ᩐⓏ࡞΅ᑛࡊࠉ85ULQJ⵫✒ࣛࣤࢡࡡ೩ྡྷ㞹☚▴ࢅࠉ㛏ᡥ᪁ྡྷ࡛༖ᙼ᪁ྡྷ࡞☚ሔ࠿ንࢂࡾࡵࡡ࡞ཱིࡽ᭨࠻ࡒሔྙ࡞ࡗ
㸧,H;࣏ࢨࣤࡵ㸫,H;࣏ࢨࣤࡵ㛏ᡥ᪁ྡྷࡡ☚ሔ࠿ୌᏽࡡሔྙ 'PF]"' ࡡ㸦㸤㸪࡞㎾ࡘࡂࠊ0㸲Ѹ ࡡሔྙࠉ ࠷࡙᳠ゞࡊࡒࠊᅒ㸪࡞㸩ᴗᠺฦ࠿࡝ࡂࠉ㛏ᡥ᪁ྡྷࡡ☚ሔን໩ࡡࡲࡡሔྙࡡ࢙࣐ࢴࢰࣤࢪࢅ♟ࡌࠊࡆࡿࡻ
'PF]"'ࡡ࡛ࡀࡡ࢙࣐ࢴࢰࣤࢪࡢࠉ0㸲㸥࡞Ẓ࡬ᑚࡈ࠷ࡽ ࠉ ⌦ ᝷ Ⓩ࡞ ࡢ ᭩ኬ ☚ ሔ  9 ࡚  QPࠉ 㸧 9 ࡚࠿ࠉ᭩ኬ☚ሔࢅኬࡀࡂࡊ࡙⾔ࡖࡒሔྙࠉ࢙࣐ࢴࢰࣤ
QP࡞࡝ࡾࡆ࡛࠿ࢂ࠾ࡾࠊḗ࡞ࠉ೩ྡྷ㞹☚▴࡞ࢪࡡ΅ᑛࡡ๪ྙࡢ0㸲㸥ࡻࡽᑛ࡝ࡂࠉ᭩ኬ☚ሔ࠿ኬ㸩ᴗᠺฦࢅຊ࠻ࡒሔྙࡡ࢙࣐ࢴࢰࣤࢪࡡ㸩ᴗ☚ሔ౪ࡀࡂ࡝ࡾ࡮࡜0㸲㸥ࡡ࢙࣐ࢴࢰࣤࢪ࡞㎾ࡘࡂࠊᅒ㸨Ꮛᛮࢅࠉᅒ㸫࡞♟ࡌࠊ㸩ᴗᠺฦ࠿9Pࡡ࡛ࡀࠉ᭩࡞༖ᙼ᪁ྡྷࡡ☚ሔ໖㒼࠿࠵ࡾሔྙࡡࠉ࡝࠷ሔྙ࡞ᑊኬ ☚ ሔ  9 ࡚  QP ࠉ  9 ࡚ QP ࠉ ྜྷ ᵕ ࡞ ࡌࡾ࢙࣐ࢴࢰࣤࢪࡡ΅ᑛ⋙ࢅ♟ࡌࠊ㸧,H;ࠉ㸫,H;࠷
9Pࡡ࡛ࡀࡐࡿࡑࡿQPࠉQP࡞࡝ࡾࠊ
ࡘࡿࡵ'PF]"' ࡡ᫤ࡡ΅ᑛ⋙࠿᭩ኬ࡚ࠉ᭩ኬ☚ሔ࠿ቌ᭩ኬ☚ሔ࠿9ࢅ㉰࠻ࡾ࡛㕪࠿㣤࿰ࡊࡢࡋࡴࡾࠊຊࡌࡾ࡞ࡗࡿ΅ᑛ⋙ࡢᑚࡈࡂ࡝ࡾࠊࡆࡡࡆ࡛࠾ࡼ᭩
≁࡞㸧9࡞࡝ࡾ࡛Ᏸධ࡞㣤࿰ࡌࡾࡒࡴࠉ☚ᴗࡡᙟࡓኬ☚ሔ࠿ኬࡀࡂ࡝ࡾ࡞ࡗࡿࠉ༖ᙼ᪁ྡྷࡡ☚ሔࡡ᭯ຝࡄ࡚㸩ᴗᠺฦࢅࡗࡂࡾࡆ࡛࠿㞬ࡊࡂ࡝ࡾࠊࡱࡒ࢙ᛮࡢ఩ୖࡌࡾࡆ࡛࠿ࢂ࠾ࡾࠊ࣐ࢴࢰࣤࢪࡵ9ࡡ࡛ࡀ࡛QPࡊ࠾㐢ࢂ࡝࠷ࡒࡴࠉ㸧9࡞ࡌࡾណ࿝࠿≁࡞࠵ࡾࢂࡄ࡚ࡢ࡝࠷࠿ࠉࡆ ḗ࡞ࠉ࢙࣐ࢴࢰࣤࢪࢅ'PF]"' ࡡ࡛ࡀࡡ࢙࣐ࢴࢰࣤࡆ࡚ࡢ᭩ኬ☚ሔ㸧9࡛ࡊࡒࠊḗ࡞㸩ᴗᠺฦ࡚࠵ࡾ࠿ࠉࢪ࡚ぞ᰹໩ࡊࠉ᭩ኬ☚ሔᙁᗐ'PF]ࢅᖲᆍ☚ሔᙁᗐ'࡚☚ሔࡡലࡀ࠿ኬࡀࡌࡁࡾ࡛ࠉ☚ሔࡡᘽ࠷࡛ࡆࢀ࡚☚ぞ᰹໩ࡊࡒࡵࡡࢅᅒ㸩࡞♟ࡌࠊ༖ᙼ᪁ྡྷࡡ☚ሔ໖㒼ᴗࡡ㛣࠿㛜ࡀࡌࡁࡾࠊࡐࡆ࡚☚ሔࡡലࡀࡢ㸪9P࡛࠿࡝࠷ሔྙࠉ㸧,H;ࡡሔྙ࡛,H;ࡡሔྙ࡚࢙࣐ࢴࢰ
ࡊࡒࠊ☚ᴗ㛣ࡡ㊝㞫ࡢࠉ85ULQJࡡ.)ࡡ᭩ᑚ࢟ࣔࢴ
ࣤࢪࡢᏰධ࡞ୌ⮬ࡊࠉ࣏ࢨࣤ࡞ࡻࡼࡍࠉ'PF]'࡚ࢪࣈ㸫PP㸝s㸨PP㸞ࢅཤ⩻࡞ࠉ㸦㸥PP࡛ࡊࡒࠊࡆࡡ࡛
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Proceedings of the 5th Annual Meeting of Particle Accelerator Society of Japanand the 33rd Linear Accelerator Meeting in Japan (August 6-8, 2008, Higashihiroshima, Japan)

2.51e (nm)_Bmax_1.5Te(nm)_Bmax_2.0T

0.9! (nm)! (nm)

2

1.5

0.8

0.7

1

0.6
0.5
0.5

1

1.5Bmax

2(T)

0.505

10B'(T/m)ᅒ㸪㸯࢙࣐ࢴࢰࣤࢪࡡ᭩  ᅒ㸫㸯࢙࣐ࢴࢰࣤࢪࡡ
ኬ☚ሔ౪Ꮛᛮ        㸩ᴗ☚ሔ౪Ꮛᛮ
200!"#$%&#Y (mm)

150

100

50

0-50

02
natural emittance 8 GeV
effective emittance 8 GeV
natural emittance 6 GeV
effective emittnce 6 GeV! ( nm)

1

0.5

0

0.02

0.04

0.06

" (m)

! (m)

-2
0 050

100

150200

250

300

350

S (m)

100

050-10050

100

150200

250

300

350

0.08

0.1" (m)ᅒ㸭㸯├⥲㒂࡞ฦᩋ㛭ᩐ࠿࠵ࡾሔྙࡡ⮤↓࢙࣐ࢴࢰࣤࢪ࡛᭯ຝ࢙࣐ࢴࢰࣤࢪ" (m)ᅒ㸮㸯├⥲㒂࡞ฦᩋ㛭ᩐࡡ࡝࠷࢛ࣈࢷ࢔ࢴࢠࢪ

-2S (m)ᅒ㸦㸥㸯├⥲㒂࡞ฦᩋ㛭ᩐࡡ࠵ࡾ࢛ࣈࢷ࢔ࢴࢠࢪ㸫㸣ࡱ࡛ࡴ೩ྡྷ㞹☚▴ࡡ㛏ᡥ᪁ྡྷ࡛༖ᙼ᪁ྡྷ࡞☚ሔࡡን໩ࢅᣚࡒࡎࡒሔྙࡡ࢙࣐ࢴࢰࣤࢪࢅゝ⟤ࡊࡒࠊࡐࡡ⤎ᯕࠉ㛏ᡥ᪁ྡྷࡡ᭩ኬ☚ሔᙁᗐ࠿ኬࡀࡂ࡝ࡾ࡞ࡗࡿ࢙࣐ࢴࢰࣤࢪࡢ΅ᑛࡊࠉ᭩ኬ࡚㸦㸤㸪ࡱ࡚΅ᑛࡌࡾࡆ࡛࠿ࢂ࠾ࡖࡒࠊ༖ᙼ᪁ྡྷ࡞㸩ᴗᠺฦࢅ୙࠻ࡾ࡛ࠉ࢙࣐ࢴࢰࣤࢪࡡ΅ᑛࡢ㛏ᡥ᪁ྡྷࡡ᭩ኬ☚ሔ࠿ᑚࡈ࠷࡮࡜ኬࡀࡂࠉ᭩ኬ☚ሔ࠿ኬࡀࡂ࡝ࡾ࡞ࡗࡿ΅ᑛᖕࡢᑚࡈࡂ࡝ࡾࡆ࡛࠿ࢂ࠾ࡖࡒࠊ ᭩ኬ☚ሔᙁᗐࢅ㸧9ࠉ㸩ᴗᠺฦࢅ㸪9P࡛ࡊ࡙ࠉ
85ULQJ⵫✒ࣛࣤࢡ࡞㐲⏕ࡊࡒࠊࡐࡡ⤎ᯕࠉ├⥲㒂ࡡฦᩋ㛭ᩐ࠿㸥ࡡሔྙࠉQPࡡ࢙࣐ࢴࢰࣤࢪࢅ
ᣚࡗ࢛ࣈࢷ࢔ࢴࢠࢪ࠿ᚋࡼࡿࡒࠊฦᩋ㛭ᩐࢅセࡊࡒሔྙࠉ⮤↓࢙࣐ࢴࢰࣤࢪࡢQPࠉ᭯ຝ࢙࣐ࢴࢰ
ࣤࢪࡢQP࡞࡝ࡖࡒࠊ⮤↓࢙࣐ࢴࢰࣤࢪࡢࠉ⌟ᅹࡡ85ULQJ⵫✒ࣛࣤࢡࡡ࡚࠵ࡾࠊ ௧୕ࡻࡽ᪜Ꮛࡡࣛࣤࢡࢅᨭ㏸ࡊ࡙࢙࣐ࢴࢰࣤࢪࢅ
ୖࡅࡾ᪁Ἢࡡୌࡗ࡛ࡊ࡙ࠉ೩ྡྷ㞹☚▴࡞㛏ᡥ᪁ྡྷ࡛༖ᙼ᪁ྡྷ࡞☚ሔࡡን໩ࢅᣚࡒࡎࡾ᪁Ἢ࠿᭯ຝ࡚࠵ࡾ
ࡆ࡛࠿ࢂ࠾ࡖࡒࠊ

ཤ⩻ᩝ⊡ᅒ㸬㸯೩ྡྷ㞹☚▴ࡡථࡽཾࠉ୯ኳࠉฝཾࡡ☚ᴗᙟ≟

0-150

50X (mm)1.5

0100! (m)ࡀࡡ㞹☚▴ථࡽཾࠉ୯ኳࠉฝཾࡡ☚ᴗᙟ≟ࢅᅒ㸬࡞♟ࡌࠊฝཾ࡚ࡡ☚ᴗ㛜ཾ࠿ኬࡀࡂࠉᐁ㝷࡞⿿షࡌࡾ࡞ࡢࡈࡼ࡝ࡾ◂✪࠿ᚪさ࡛ᛦࢂࡿࡾ࠿ࠉᐁ⌟୘ྊ⬗࡝ࡵࡡ࡚ࡢ࡝࠷ࠊ௧୕ࡡࣂ࣒࣭ࣚࢰࢅ⏕࠷࡙࢛ࣈࢷ࢔ࢴࢠࢪࢅゝ⟤ࡊࡒࠊ⤎ᯕࢅᅒ㸮࡞♟ࡌࠊ࢙࣐ࢴࢰࣤࢪࡢ1.68 nm࡚࠵ࡖࡒࠊ⌦ㄵⓏ᭩ᑚೋ࠿0.65 nm࡚࠵ࡾ࠾ࡼ⣑2.6ಶ
ኬࡀ࠷ࡆ࡛࠿ࢂ࠾ࡾࠊࡔ࡝ࡲ࡞SPring-8ࡡ⌦ㄵೋࡢ
2.21 nmࠉスゝೋࡢ6.99 nm࡚ࠉࡐࡡẒࡢ3.2࡚࠵ࡾࠊ࢙࣐ࢴࢰࣤࢪࢅࡈࡼ࡞ᑚࡈࡂࡌࡾࡒࡴࠉ├⥲㒂ࡡฦᩋ㛭ᩐࢅセᐖࡌࡾࡆ࡛࡞ࡊࡒࠊᅒ㸭࡞├⥲㒂ࡡฦᩋ㛭ᩐࡡೋ࡛࢙࣐ࢴࢰࣤࢪࡡ㛭౿ࢅ♟ࡌࠊฦᩋ㛭ᩐ࠿ቌኬࡌࡾ࡛⮤↓࢙࣐ࢴࢰࣤࢪࡢ΅ᑛࡌࡾ࠿ࠉฦᩋ㛭ᩐ࡞ࡻࡾ࢓ࣤࢩ࣭ࣖࣝࢰ㒂ࡡࡲ࠾ࡄࡡ࢙࣐ࢴࢰࣤࢪࡢቌኬࡌࡾࠊࡐࡆ࡚ฦᩋ㛭ᩐ࡞ࡻࡾຝᯕࡱ࡚ྱࡴࡒ᭯ຝ࢙࣐ࢴࢰࣤࢪࡵゝ⟤ࡊࡒࠊࡆࡿࡻࡽฦᩋ㛭ᩐ࠿
0.06mࢅ㉰࠻ࡾ࡛ࠉ᭯ຝ࢙࣐ࢴࢰࣤࢪࡢ㣤࿰ࡊࡢࡋࡴࡾࡆ࡛࠿ࢂ࠾ࡾࠊࡐࡆ࡚ฦᩋ㛭ᩐࢅ0.062 m࡛ࡊ࡙࢛ࣈࢷ࢔ࢴࢠࢪࢅゝ⟤ࡊࡒࠊ⤎ᯕࢅᅒ㸦㸥࡞♟ࡌࠊ⮤↓࢙࣐ࢴࢰࣤࢪࡢ0.63 nmࠉ᭯ຝ࢙࣐ࢴࢰࣤࢪࡢ
0.83 nm࡞࡝ࡾࠊ⌟ᅹࡡSPring-8⵫✒ࣛࣤࢡࡡ࢙࣐ࢴ
ࢰࣤࢪࡢ3.4 nm࡚࠵ࡾ࠾ࡼࠉ1/5.4࡞࡝ࡾࡆ࡛࠿ࢂ࠾
ࡾࠊ

[1] M. Sands,“The Physic of Electron Storage Rings”,
SLAC-121, 1970.
[2] K. Tsumaki, N. Kumagai, “Very low emittance light source
storage ring”, Nucl. Instr. and Meth. A 565 (2006) 394.
[3] J. Guo, T. Raubenheimer, “LOW EMITTANCE E -/E +STORAGE RING DESIGN USING BENDING MAGNETSWITH LONGITUDINAL GRADIENT” EPAC’02, Paris,
2002, p. 1136
[4] R. Nagaoka, A. Wrulich, “Emittance minimization withlongitudinal dipole field variation”, Nucl. Instr. and Meth. A
575 (2007) 292.
[5] K. Tsumaki, “EMITTANCE REDUCTION BY
LONGITUDINALLY VARYING DIPOLE FIELD”
EPAC’08, Genoa, 2008, p. 2118.

-110-