È Ä Z Ø m 8 0È S Ëù p § Þ X ¢ M ø m É Ä Z ØP M Ä Z ØA 0 Ö « ] §V ê s ì Å

(1)

Ä k

È Ä Z Ø m 8 0È S Ëù p § Þ X ¢ M ø m É Ä Z ØP M Ä Z ØA 0 Ö « ] §V ê s ì Å

-

!

H* å M Î 3

^∗

· T , Û o ¸

×

æ © @ / < Æ § Ó ü to < Æõ , " fÖ ¦ 156-756 (2008¸ 12 Z 4 5{ 9 ~ Ã Î6 £ §)

l { 9 ì ro l _ $ í 0 p x` ¦ þ j& h o l 0 AK " f H 5 Å ql c Ã º5 Å x> ü < l { 9 ì ro l t ¦ e

H c : £ ¤$ í ` ¦ B g Ar v H כ s B Ä º × æכ ¹ . þ j H 1 l x â s o < Æ ½ ¨ è 5 Å ql ½ ¨ r [ O \ [ O u ) a 1

l

x â @ / < Æ § Â Ò[ O Ù þ õ < Æ ½ ¨ è_ l { 9 ì ro l PA (particle analyzer) H [ O u Ê ê z ´r ) a _ Û ¼à Ô z

´+ « >\ " f î r1 l x| ¾ Ó ì rK 0 p xs [ O > u (p/∆p ∼ 10,000)\ q K 10C $ ) a ° ú כ (∼1,000)` ¦ Ð% i . : r

½ ¨\ " f H c ì rí ß B g A` ¦ : xô Ç PA_ ì rK 0 p x ¾ Ó © ½ ¨\ ¦ Ã º' % i . s \ ¦ 0 AK c í ß ¸ á Ô Ð Õ

ªÏ þ TRANSPORT ï× ¼\ ¦ s 6 x # þ j& h o ) a c Ã º5 Å x ¸| ` ¦ ¹ 1 Ô ¦ 1 l xr \ c ^ _ î r1 l x| ¾ Ó ( f

` ¦ × ¦s l 0 AK c Ã º5 Å x> \ [ O u ô Ç c _ þ ta Å @` ¦ s 6 x % i Ü ¼ 9,

¹²

C+

⁴

He (E

4He,lab

= 120 MeV) ò ø Í

$ í

í ß ê ø Í z ´+ « >` ¦ : xK p/∆p ∼ 5,000_ ¾ Ó © ) a î r1 l x| ¾ Ó ì rK 0 p x` ¦ % 3 % 3 .

PACS numbers: 29.30.Aj, 29.27.Eg, 29.27.Fh, 25.70.Hi

Keywords: l{9ìrol, c ìríß BgA, c Ãº5Åx, TRANSPORT ï×¼, {9 ìrFg<Æ

I. " e Â ] Ø

Z

} É r ì rK 0 p xõ ± ú É r C â > Ã º 1 p x_ © & h Ü ¼ Ð #

l { 9 ì ro l (magnetic spectrograph) H c ¤ èl (in- beam) { 9 ì rF g < Æ` ¦ l ì ø ÍÜ ¼ Ð ô Ç Ù þ ½ ¨ ¸ ½ ¨, Ù þ ì

ø

Í6 £ x ½ ¨ 1 p x_ ª ô Ç ì r \ " f V , o Ö ¸6 x÷ & ¦ e . : £ ¤ y

1990¸ × æì ø Í s Ê ê ~ ½ Ó $ í Ù þ 7 á xc _ Ø ¦s 0 p xK f

\

~ ½ Ó $ í Ù þ 7 á xc Ò q t$ í © u ü < ½ + Ë # ~ ½ Ó $ í Ù þ 7

á

x_ & ñ S X ô Ç | 9 | ¾ Ó 8 £ ¤& ñ , Ù þ ½ ¨ ¸ ½ ¨ 1 p x_ ì r Ð Õ ª Ö ¸ 6

x% ò % i s V , # Qt ¦ e [1].

{ 9

5 Å ql ÐÂ Ò' Ø ¦ ) a c õ ³ ð& h (target)ç ß _ 0

A& h Ù þ ì ø Í6 £ x` ¦ : xK ª ô Ç 7 á xÀ Ó_ { 9 Ò q t$ í ÷ &

¦ s X O > ~ ½ ÓØ ¦ ) a { 9 H s Ê ê l { 9 ì ro l \ ¦ : x õ

H õ & ñ \ " f é ß 0 A { © { 9 _ î r1 l x| ¾ Ó (p/Q) Ü

¼ Ð & ñ _ ÷ & H l y © $ í Ò ¦ (magnetic rigidity, Bρ)\ _ K

ì ro ) a . 7 £ ¤, Å Ò# Q l © \ " f { 9 H 6

£

§ü < ° ú s { 9 _ î r1 l x| ¾ Óõ \ " f Ð É r / B GÒ ¦ ì

ø

Í â (ρ)` ¦ t > ÷ & ¦,

ρ = p

QB (1)

s

\ , l © _ [ jl \ ¦ ¸] X # Ä ºo " é ¶ H 7 á x À

Ó_ { 9 ë ß ` ¦ í& h (focal plane)\ í& h ´ ú Æ Òl H

כ

s 0 p x 9 þ j7 á x& h Ü ¼ Ð í& h Ø ¦l r Û ¼% 7 (focal

∗E-mail: [email protected]

plane detection system)` ¦ s 6 x # ¦ì rK 0 p x_ Û ¼& 7 à Ô

! 3

` ¦ % 3 > ) a .

5 Å ql ÐÂ Ò' Ø ¦÷ & H c É r s : r" ¶ é Ø ¦Â Ò\ " f ³ ð& h 0

Au \ s Ø Ôl t í& h ´ ú Æ Òl ü < c _ â Ð â ` ¦ 0 A K

s × æF G (dipole), × æF G (quadrupole) 1 p x_ ª ô Ç

$ 3 (electromagnet)Ü ¼ Ð ½ ¨$ í ) a 4 ¤¸ ú ô Ç ½ ¨ ¸_ c Ã º 5

Å

x> \ ¦ u 9 : £ ¤$ í s & ñ ) a . l { 9 ì ro l % i r {

9 _ ì ro ü < í& h ´ ú Æ Òl \ ¦ 0 AK s × æF G x 9 × æF G

$ 3 Ü ¼ Ð ½ ¨$ í ÷ &Ù ¼ Ð l { 9 ì ro l ¦Ä »_ c : £ ¤$ í ` ¦

. " f, l { 9 ì ro l _ $ í 0 p x þ j& h o\ ¦ 0 AK

"

f H 5 Å ql Â Òì r_ c : £ ¤$ í õ l { 9 ì ro l _ Õ ª כ

`

¦ ³ ð& h 0 Au \ " f B g A (matching)r v H כ s B Ä º × æ כ

¹ . : r ½ ¨\ " f H ª ô Ç c B g A l Õ ü t × æ { 9 ì ø Í& h Ü ¼

Ð ì rí ß B g A (dispersion matching)s Ô ¦o H ³ ð& h 0 A u

\ " f c _ Ðì rí ß (lateral dispersion)` ¦ B g Ar v H

~

½

ÓZ O ` ¦ : x # l { 9 ì ro l _ ì rK 0 p x` ¦ ¾ Ó © r v l 0

Aô Ç ½ ¨\ ¦ Ã º' % i . 2 © \ " f H : r ½ ¨\ s 6 x ) a 1 l x

â

@ / < Æ § Â Ò[ O Ù þ õ < Æ ½ ¨ è (Center for nuclear study, s

CNS)_ ¦ì rK 0 p x l { 9 ì ro l PA (particle analyzer)\ ¦ è> h ¦, 3 © \ " f H s : rc Ã º5 Å x í ß ¸

ï× ¼ TRANSPORT [2]\ ¦ s 6 xô Ç c B g A_ þ j& h o

½

¨\ @ /ô Ç ? /6 x` ¦ Ò ¦ כ s 9, 4 © \ " f H

¹²

C+p ò ø Í$ í í

ß

ê ø Íz ´+ « >` ¦ s 6 xô Ç ì rK 0 p x ¾ Ó © _ Û ¼à Ô õ \ ¦ è> h

¦ ô Ç .

-362-

(2)

Fig. 1. Top view of PA systems. The red solid lines represent the trajectories of particles in the PA.

Table 1. The main specifications of PA.

Dispersion (D) 2.79

Horizontal magnification (M

H

) 0.37 First order resolution 10,000 Maximum solid angle 8.2 msr Maximum field strength

- dipole 12.7 kG

- quarupole 0.956 kG/cm

Maximum current

- dipole 800 A

- quarupole 570 A

Magnet weight 38 t

Total weight 55 t

II. w Ä Z ØA 0 Ö « M ø m É Ä Z ØP M , PA

_ × æF G $ 3 õ ¿ º > h_ s × æF G $ 3 Ü ¼ Ð

½

¨$ í ) a QDD (quadrupole-dipole-dipole) { 9 _ l { 9

ì ro l PA H 1970¸ @ / Ê êì ø Í { 9 : r 1 l x â @ / < Æ § Â Ò[ O Ù

þ

õ < Æ ½ ¨ è\ [ O u ) a s A s Ê ê & ³F \ s Ø Ôl t Ù þ ì

ø

Í6 £ x ½ ¨ ì r \ " f $ í / B N& h õ \ ¦ ¸Ø ¦K M ® o [3–

5]. ³ ð& h © (target chamber)ü < í& h © (focal plane chamber)\ ¦ í < Êô Ç PA r Û ¼% 7 _ > h| Ä Ì ¸\ ¦ Fig. 2\

? /% 3 ¦, PA_ l : r ª ` ¦ Table 1\ ? /% 3 . PA

H î r1 l x| ¾ Ó ì rK 0 p x_ [ O > u p/∆p ∼ 10,000 \ s Ø Ô

¦, þ j@ / { 9 ^ y s 8.2 msr Z } É r î r1 l x| ¾ Ó ì rK 0 p xõ H {

9 ^ y _ © & h ` ¦ t ¦ e . ¢ ¸ô Ç { 9 s : rc _ ~ ½ Ó

¾

Ó\ @ /K −20

^◦

\ " f +120

^◦

t r s 0 p x #

"

f V , É r y ¸ % ò % i _ y ì r í 8 £ ¤& ñ (angular distribution measurement)s 0 p x .

l { 9 ì ro l _ â Ä º í' \ " f µ 1 ÏÒ q t H kine- matic broadening effect Ð K s × æF G $ 3 _ Ã º

´ ú

§` ¦Ã º2 ¤ " é ¶ H { 9 \ ¦ í& h \ í& h ´ ú Æ Òl H כ s

Ã º Z 4K [6]. t ë ß s â Ä º\ H © q _ Á º> 1 p x

^ _ ½ © ¸ & t ¦ s \ É r q 6 x 7 £ xü < ¸ _ # Q

9¹ ¡ § 1 p x # Q é ß & h [ þ ts Ã ºì ø Í ) a . PA_ â Ä º\ H s × æ F

G $ 3 ` ¦ ¿ º > hë ß 6 x < ÊÜ ¼ Ð+ è+ þ A o\ ¦ u % i ¦ Fig. 2\ Ð# t H ü < ° ú s 100 cm U ´s _ í& h ` ¦ {

9 { 9 _ C & h \ @ /K © @ /& h Ü ¼ Ð l Ö ¦# Qt ¸2 ¤ [ O

>

¦ ({ 9 × æd C & h \ @ / # í& h s 35

^◦

l Ö ¦# Q 4

R e .), í& h ^ _ 0 Au \ ¦ o0 p xH # kine- matic broadening effect\ ¦ Ð& ñ ¸2 ¤ % i . ¢ ¸ô Ç " é ¶+ þ A

¢

¸ H " é ¶+ þ A 1 p x_ " f Ð É r ¸ ª õ ß ¼l (0.1, 1, 2, Õ ªo

¦ 5 msr)\ ¦ c _ þ ta Å @` ¦ ³ ð& h õ l { 9 ì ro l s

, ³ ð& h Ü ¼ ÐÂ Ò' 35 cm t & h \ [ O u ½ + É Ã º e ¸2 ¤ # {

9 { 9 \ @ /ô Ç { 9 ^ y ` ¦ & ñ _ ½ + É Ã º e ¸2 ¤ % i .

CNS_ PA H þ j H 1 l x â s o < Æ ½ ¨ è (s RIKEN)

5 Å ql ½ ¨ z ´+ « >1 l x ? /_ E2 z ´+ « >f . Ë\ s 1 l x·[ O u ÷ &% 3

. s \ H CNS SF- s 9 þ t Ðà Ô : r (K = 67)õ ÷ &

#

Q $ \ -t c ` ¦ s 6 xô Ç Ù þ ì ø Í6 £ x ½ ¨\ Ö ¸6 x÷ &# Q M ® oÜ ¼

, & ³F H K = 540_ RRC (RIKEN ring cyclotron)ü <

# Z } É r \ -t % ò % i \ " f_ ½ ¨ 0 p xK & .

Õ

ª Q [ O u Ê ê s À Ò# Q _ Û ¼à Ô z ´+ « > õ % 3 # Q î r 1

l

x| ¾ Ó ì rK 0 p x É r p/∆p ∼ 1,000 Ð · ú ¡" f / å Lô Ç [ O > u p/∆p ∼ 10,000\ q # \ P C É r ° ú כs . { 9 ì ø Í& h Ü ¼

Ð 5 Å ql ÐÂ Ò' Ø ¦÷ & H c _ \ -t Z }` ¦Ã º2 ¤ c

^ _ î r1 l x| ¾ Ó\ @ /ô Ç Ô ¦S X z ´ ¸ % i r & . s X O > &

î r1 l x| ¾ Ó\ @ /ô Ç Ô ¦S X z ´ ¸ H l { 9 ì ro l _ ì rK 0 p x

\

¸ H % ò ¾ Ó` ¦ p u > ) a . " f PA_ $ í 0 p x` ¦ þ j& h

o l 0 AK " f H D h Ðî r 5 Å ql r Û ¼% 7 õ _ c : £ ¤$ í \

@

/ô Ç B g As B Ä º × æכ ¹ .

III. TRANSPORT Â© õ u § T Ó Þ X ¢ Ä k È 8 0È S Ë :

X ì Ä× D ì Å

c

Ø ¦ ÐÂ Ò' PA t _ c Ã º5 Å x _ > h| Ä Ì ¸ H Fig. 2ü < ° ú . c É r RILAC (RIKEN Linear Accelerator, RIKEN + þ A 5 Å ql ) ÐÂ Ò' Ø ¦÷ & ¦ RRC\ ¦ u " f

\

-t 7 £ x ) a . RRC_ Ø ¦Â Ò ÐÂ Ò' ³ ð& h © ? / _

³ ð& h t _ â Ð\ H 6> h_ × æ × æF G $ 3 (quadrupole triplet magnets)õ 6> h_ s × æF G $ 3 (dipole magnets)s C u ÷ &# Q e .

c

B g A` ¦ 0 Aô Ç ~ ½ ÓZ O [ þ t Ð H kinematic correction, Ð ì

rí ß B g A (lateral dispersion matching, ¢ ¸ H { 9 ì ø Í& h Ü ¼ Ð ì

rí ß B g As Â Ò É r .), í& h ´ ú Æ Òl B g A (focus match- ing), Õ ªo ¦ y ì rí ß B g A (angular dispersion matching) 1

p

xs e [7]. : r ½ ¨\ " f H · ú ¡" f / å Lô Ç c B g A ~ ½ ÓZ O

(3)

Fig. 2. Beam transport line from the RRC to the focal plane of PA. Beam transport magnet elements consist of the six quadrupole triplet magnets (1)QTA01, 2)QTA02, 5)QTA11, 6)QTD12, 11)QT2A1, and 12)QT2A1), and six dipole magnets including switching magnets (3)DAA1, 4)DMA1, 7)DAD1, 8)DAD2, 9)DMD2, and 10)SW21).

×

æ ì rí ß B g A` ¦ : xK ì rK 0 p x` ¦ ¾ Ó © ï % i . s \ ¦ 0 A K

c Ã º5 Å x í ß ¸× ¼ ï× ¼ TRANSPORT\ ¦ s 6 x # y

$ 3 \ f Ë 9t H À Ó 1 p x_ þ j& h o ) a c Ã º5 Å x> _

Ã º\ ¦ & ñ ¦ % i . c Ã º5 Å x> _ : £ ¤& ñ 0 Au \ " f e

_ _ { 9 \ @ /ô Ç & ñ Ð H 6 £ §õ ° ú É r 7 ' (X) _

+ þ AI Ð ³ ð & ³ ) a .

X =



 

  x θ y ϕ l δ



 

 

(2)

0 A_ d \ " f x, y, Õ ªo ¦ l É r y y c ' ~ ½ Ó ¾ Ó\ @ /K Ã

º¨ î , Ã ºf , Õ ªo ¦ ' ~ ½ Ó ¾ Ó\ @ /ô Ç c _ ß ¼l (é ß 0 A

H cm)\ ¦ · p . θü < ϕ H y y c ' ~ ½ Ó ¾ Ó\ @ / K

Ã º¨ î õ Ã ºf ~ ½ Ó ¾ Ó\ @ /ô Ç c _ divergence (é ß 0 A H mrad)\ ¦, t } Ü ¼ Ð δ H : £ ¤& ñ 0 Au \ " f c _ î r1 l x| ¾ Ó ( f

(∆p/p)\ ¦ _ p ô Ç . í ß ¸ \ ¦ 0 AK { 9 R-' § > = + þ A d

(first order R-matrix formalism)` ¦ 6 x % i . R-'

§

>

= É r c Ã º5 Å x> \ ¦ : xõ H ¸ H { 9 [ þ t\ & h 6 x÷ & H 5

Å

x ' § > = (transfer matrix)s . íl 0 Au ü < þ j7 á x0 Au \

"

f_ c : £ ¤$ í 7 ' \ ¦ y y X(0)ü < X(1)s ¦ ô Ç , c

Ã º5 Å xd É r R-' § > =` ¦ s 6 x # 6 £ §õ ° ú s ³ ð & ³ ) a .

X(1) = RX(0) (3)

×

æd @ /g A (mid-plane symmetry)\ ¦ t ¦ e H & ñ l

(static magnetic) r Û ¼% 7 \ @ /K d 3_ R É r 6 £ §õ

480 500 520 540 560

0 500 1000 1500

Counts 2000

Relative momentum (ch)

0 200 400 600 800 1000 1200

16 O g.s.

12 Cg.s.

(

b

)

(a)

Fig. 3. Momentum spectra with (a) achromatic beam transportation and (b) beam matching mode transporta- tion. In (a), the elastically scattered alphas from

¹²

C and

¹⁶

O were not separated. However, in (b), they were clearly separated and the momentum spread was 0.02%

in FWHM.

° ú

É r 6 × 6 ' § > =d Ü ¼ Ð j þ t Ã º e .

R =



 

 

R

11

R

12

0 0 0 R

16

R

21

R

22

0 0 0 R

26

0 0 R

33

R

34

0 0 0 0 R

43

R

44

0 0 R

₅₁

R

₅₂

0 0 1 R

₅₆

0 0 0 0 0 1



 

 

(4)

0 A ' § > =_ ½ Ó × æ R

16

ì rí ß (dispersion)\ K { © H ½ Ó s

. R-' § > = É r c Ã º5 Å x> \ ¦ ½ ¨$ í ¦ e H ¸ H ½ ¨$ í כ ¹

è[ þ t É r y y \ @ /K : £ ¤$ í o ) a . " f c Ã º5 Å x> ^

\

@ /ô Ç 8 ú x R-' § > = É r 6 £ §õ ° ú s ³ ð & ³ ) a .

R = R(n)R(n − 1) · · · R(3)R(2)R(1) (5)

#

l " f R(n) É r c Ã º5 Å x> \ ¦ ½ ¨$ í ¦ e H y ½ ¨$ í כ ¹ è

t ¦ e H ¦Ä »_ 5 Å x' § > =` ¦ _ p ô Ç . & ³F z ´+ « >

&

h

Ü ¼ Ð RRC Ø ¦Â Ò\ " f_ c _ : £ ¤$ í ` ¦ 8 £ ¤& ñ ½ + É Ã º \ O l M

:ë H\ íl 0 Au 7 £ ¤, RRC Ø ¦Â Ò\ " f_ c : £ ¤$ í 7 '

H 5 Å ql ] j \ " f ] j/ B N H [ O > u \ ¦ 6 x % i .

(4)

Table 2. Optimum parameters for the beam transporta- tion.

Position

x (cm) y (cm)

R

16

(cm/%) RRC extraction 0.33 0.47 2.50

Beam slit 0.89 0.26 18.39 Target 0.13 0.17 8.90 Focal plane 0.07 0.62 0.02

Æ

Ò& h Ü ¼ Ð c \ -t \ É r c Û ¼Û ¼ Ð_ î r1 l x| ¾ Ó Ô ¦S X z

´ ¸\ ¦ × ¦s l 0 A # 5)QTA11õ 6)QTD12 s _ 0 A u

\ (Fig. 2) ç ß ` ¦ ¸] X ½ + É Ã º e H c _ þ ta Å @` ¦ [ O u

% i

. c _ þ ta Å @_ % i ½ + É` ¦ F G@ / o ¦ þ j& h _ ¸| ` ¦ ¹ 1 Ôl 0

AK " f 6 £ §õ ° ú É r ½ Ó` ¦ ¦ 9ô Ç > í ß ` ¦ Ã º' % i .

$ c _ þ ta Å @ 0 Au \ " f c s & h É r î r1 l x| ¾ Ó ( f ` ¦ t ¸ 2

¤ × þ l 0 AK " f H c _ þ ta Å @ 0 Au \ " f c ì rí ß s 0 p x ô

Ç ô Ç ß ¼ ¸2 ¤ K ô Ç . t ë ß 1 l xr \ c À Ó ([ jl )_

<

Hz ´` ¦ þ j è o l 0 AK " f c _ l & h ß ¼l H 0

p

xô Ç ô Ç > K ô Ç . t } Ü ¼ Ð c _ þ ta Å @ 0 Au \ " f_

H c ì rí ß õ É r c s Ý ¼\ ¦ ë ß 7 á ¤r ( õ 1 l xr \ RRC _

Ø ¦0 Au ÐÂ Ò' PA\ s Ø Ôl t ^ _ c Ã º5 Å x>

\

@ /K c ì rí ß B g A ¸| ` ¦ ë ß 7 á ¤r v H ¸| ` ¦ ¸Ø ¦K

ô Ç .

RRC ÐÂ Ò' Ø ¦÷ & H 120 MeV_ \ -t \ ¦ · ú

c \ @ / # 0 A\ " f / å Lô Ç ¸| [ þ t` ¦ ë ß 7 á ¤ ¸2 ¤ TRANSPORT ï× ¼\ ¦ s 6 xô Ç í ß ¸ \ ¦ Ã º' ô Ç õ , þ

j& h o ) a c Ã º5 Å x> Ã º\ ¦ s 6 x # % 3 É r c Ã º5 Å x> Å Ò כ

¹ 0 Au \ @ /ô Ç Ã ºf , Ã º¨ î » ¡ ¤ © _ ß ¼l ü < c ì rí ß 1 p x_ c

: £ ¤$ í \ @ /ô Ç ° ú כ` ¦ Table 2\ ? /% 3 . ³ ð\ " f Ð# t

H ü < ° ú s , Å Òכ ¹ 0 Au \ " f_ c : £ ¤$ í s · ú ¡\ " f /

å

Lô Ç ¦ 9 ½ Ó[ þ t` ¦ 1 l xr \ ë ß 7 á ¤r ( ` ¦ · ú Ã º e .

IV.

¹²

C+

⁴

He mV R Ë m m ÷ m Ç] M öù p § T Ó Þ X ¢ Ä k È 8

0È S Ë ? _ ²

3 © \ " f Ã º' ô Ç c B g A õ \ É r ì rK 0 p x ¾ Ó © ` ¦ S

X

l 0 A #

¹²

C+

⁴

He ò ø Í$ í í ß ê ø Í z ´+ « >` ¦ Ã º' % i

. PA_ y ¸ H c ' ~ ½ Ó ¾ Ó\ @ /K 10

^◦

Ð % i Ü ¼ 9, f

â 0.1 msr_ " é ¶+ þ A (circle-type) PA _ þ ta Å @` ¦ [ O u % i

. c É r RRC ÐÂ Ò' Ø ¦÷ & H 120 MeV_

⁴

He c ` ¦ s 6

x % i Ü ¼ 9, ³ ð& h É r 1.5 µm ¿ ºa _ Lumirror (C

10

H

8

O

4

, x

9 ¸ ∼ 1.40 g/cm

³

) 9 2 £ §` ¦ 6 x % i . PA_ l Ã

º (magnetic parameters) H

¹²

C ³ ð& h Ù þ Ü ¼ ÐÂ Ò' ò ø Í$ í í

ß

ê ø Í÷ & H · ú { 9 í& h _ î rX <\ ¸ ¸2 ¤ [ O & ñ

% i . · ú { 9 _ Ø ¦ É r s Ú Ôo × ¼+ þ A Û ¼ > Ã ºl

(hybrid gas counter)ü < e ¦ Û ¼h Ë : $ 3 F g Ø ¦l Ð ½ ¨$ í ) a

í& h Ø ¦ r Û ¼% 7 ` ¦ s 6 x % i . s Ø ¦ r Û ¼% 7 ` ¦ : x K

{ 9 _ C & h ` ¦ 8 £ ¤& ñ ¦ ∆E-E telescope Z O Ü ¼ Ð { 9

\

¦ ó ø ÍZ > % i .

>

) a c _ þ ta Å @ ¸| \ @ /ô Ç ª ô Ç ¸½ + Ë` ¦ : xK , þ j& h o

)

a c Ã º5 Å x ¸| ` ¦ ¹ 1 Ô ¦ % i . Õ ª õ Table 2\

è ß c ¸| ` ¦ ë ß 7 á ¤r v H Ã º5 Å x> _ Ã º5 Å x Ã ºü < ; ¤ 0.3 mm (left : 0.1 mm and right : 0.2 mm)_ c _ þ ta Å @` ¦ & h 6 x Ù

þ

Ã º5 Å x ¸× ¼_ · ú c ` ¦ s 6 xô Ç 1 l x{ 9 ô Ç z ´+ « >` ¦ Ã º'

% i

. Achromatic c Ã º5 Å x ¸× ¼ < Ê É r Ù þ ì ø Í6 £ x z ´+ « >r @ / Â

Òì r 6 x÷ & H c Ã º5 Å x ¸× ¼ Ð+ ³ ð& h + '_ l { 9 ì r o

l H ¦ 9 t · ú § ¦ ³ ð& h 0 Au \ " f c _ ß ¼l ü < ì rí ß

`

¦ þ j è o ¸2 ¤ H Ã º5 Å x ¸× ¼\ ¦ ´ ú ô Ç . Fig. 3\ " f

^

¦ Ã º e 1 p ws s â Ä º H í& h 0 Au \ " f H î r1 l x| ¾ Ó ( f Ü

¼ Ð #

¹²

Cü < Lumirror ³ ð& h \ í < Ê÷ &# Q e H

¹⁶

O Ü

¼ ÐÂ Ò' ò ø Í$ í í ß ê ø Í ) a

⁴

He { 9 ½ ¨ì r÷ &t · ú § H . Õ ª

Q c B g A ¸× ¼ Ð Ã º5 Å x ) a c ` ¦ & h 6 xô Ç â Ä º H

¹²

Cü <

16

O Ü ¼ ÐÂ Ò' ò ø Í$ í í ß ê ø Í ) a

⁴

He { 9 " î S X > ½ ¨ì r÷ &

H כ ` ¦ · ú Ã º e Ü ¼ 9 s â Ä º \ -t ì rK 0 p x É r FWHM (full width at half maximum) ∼ 45 keV % i . s \ ¦ î r1 l x

|

¾

¼ Ð PA_ þ j í [ O > u p/∆p ∼ 10,000õ q § | ¨ c ë

ß

ô Ç a % ~ É r õ s ¦ RIKENÜ ¼ Ð PA\ ¦ s 1 l x # z ´r ô Ç '

Í

_ Û ¼à Ô õ (p/∆p ∼ 1,000)\ q K 5C & ñ ¸

¾

V. + s Ç Â ] Ø

c

H

²⁸

Si(

⁴

He,

⁶

He)

²⁶

Si Ù þ ì ø Í6 £ x` ¦ : xô Ç ;^ Ù þ Ó ü to < Æ& h Ü ¼

Ð × æכ ¹ô Ç

²⁶

Si Ù þ ½ ¨ ¸\ ¦ ½ ¨ l 0 Aô Ç z ´+ « >s $ í / B N& h Ü

¼ Ð Ã º' ) a e Ü ¼ 9 [8], ¢ ¸ô Ç

²⁸

Si+

⁴

He ò ø Í$ í í ß ê ø Í_ y

ì r í 8 £ ¤& ñ z ´+ « > % i r optical model analysis\ ¦ : xK Õ

ª õ $ í / B N& h Ü ¼ Ð ¸Ø ¦÷ &% 3 [9]. & ³F PA\ ¦ s 6 x ô

Ç ª ô Ç ½ ¨ D h\ v> > S \ ÷ & ¦ e . Õ ª × æ

(

⁴

He,

⁸

He) Ù þ ì ø Í6 £ x` ¦ s 6 xô Ç × æ$ í õ e ç Ù þ 7 á x (neutron- rich nuclei)\ ' aô Ç ½ ¨s . (

⁴

He,

⁸

He) Ù þ ì ø Í6 £ x É r 4> h _

× æ$ í s ÷ & H Ù þ ì ø Í6 £ xs l M :ë H\ f t ¸ ú

· ú

94 R e t · ú § É r × æ$ í íõ e ç Ù þ 7 á x (very neutron- rich nuclei)\ @ /ô Ç D h Ðî r õ l @ / ) a . Õ ª Q , s

â

Ä º 4> h_ × æ$ í s ÷ &# Q Ù ¼ Ð Ù þ ì ø Í6 £ xé ß & h s

B Ä º 8 £ ¤& ñ ` ¦ 0 AK " f H { 9 ó ø ÍZ > r Û ¼% 7 _ Z }

(5)

É

r ì rK 0 p xõ ± ú É r C â > Ã º 9 Ã º& h Ü ¼ Ð כ ¹½ ¨ ) a . s

â

Ä º כ ¹½ ¨÷ & H l { 9 ì ro l r Û ¼% 7 _ î r1 l x| ¾ Ó ì rK 0 p x

É

r p/∆p ∼ 2,500 & ñ ¸s . PA H s 3 l q& h \ Â Ò½ + Ë H [

j> þ j ¦ Ã ºï r_ l { 9 ì ro l s . : r ½ ¨\ ¦ : xK (

⁴

He,

⁸

He) Ù þ ì ø Í6 £ x ½ ¨\ ¦ 0 Aô Ç þ j èô Ç_ ¸| ` ¦ ° ú Æ Ò% 3 Ü

¦ e .

P c

p 8 ý ò k >

s

Y c

p w Ã U Ø ô

[1] T. Uesaka, S. Shimoura, H. Sakai, G. P. A. Berg, K.

Nakanishi, Y. Sasamoto, A. Saito, S. Michimasa, T.

Kawabata and T. Kubo, Nucl. Instr. Meth. B 266, 4218 (2008).

[2] K. L. Brown, D. C. Carey, Ch. Iselin and F.

Rothacker: Transport, a Computer Program for De- signing Charged Particle Beam Transport Systems (CERN-80-04, Geneve, 1980).

[3] S. Kato, T. Hasegawa and M. Tanaka, Nucl. Instr.

Meth. 154, 19 (1978).

[4] M. H. Tanaka and S. Kubono, Phys. Lett. B 161, 52 (1985).

[5] S. Michimasa, S. Kubono, S. H. Park, T. Teranishi, Y.

Yanagisawa, N. Imai, Zs. Fulop, X. Liu, T. Minemura, C. C. Yun, J. M. D’Auria and K. P. Jackson, Nucl.

Phys. A 718, 581c (2003).

[6] K. Iwatani, H. Yokomizo, M. Tanaka, S. Kato and T.

Hasegawa, Nucl. Instr. Meth. 171, 61 (1980).

[7] H. Fujita, Y. Fujita, G. P. A. Berg, A. D. Bacher, C. C. Foster, K. Hara, K. Hatanaka, T. Kawabata, T. Noro, H. Sakaguchi, Y. Shimbara, T. Shinada, E.

J. Stephenson, H. Ueno and M. Yosoi, Nucl. Instr.

Meth. A 484, 17 (2002) and references therein.

[8] Y. K. Kwon, C. S. Lee, J. Y. Moon, J. H. Lee, J. Y.

Kim, M. K. Cheoun, S. Kubono, H. Yamaguchi, J. J.

He, A. Saito, Y. Wakabayashi, H. Fujikawa, G. Ama- dio, N. Iwasa, N. Inafuku, L. H. Khiem, M. Tanaka, Y. Fuchi, A. A. Chen, S. Kato and N. Fukunishi, J.

Korean Phys. Soc. 51, 1635 (2007).

[9] Y. K. Kwon, C. S. Lee and S. Kubono, J. Korean

Phys. Soc. 53, 1141 (2008).

(6)

Study of the Improvement of the Momentum Resolution of a Magnetic Spectrograph by Beam Dispersion Matching

Young Kwan Kwon

^∗

and Chun Sik Lee

Department of Physics, Chung-Ang University, Seoul 156-756 (Received 5 December 2008)

If the capability of a magnetic spectrograph is to be optimized, it is important to match the beam characteristics between the beam line and the spectrograph. Recently, a PA (particle analyzer) from the Center for Nuclear Study (CNS), University of Tokyo, was installed at the experimental hall at the RIKEN accelerator research facility. In the test experiment after installation, the momentum resolution was measured to be p/∆p ∼ 1,000, which was ten times worse than the designed value (p/∆p ∼ 10,000). We studied improvement of the momentum resolution of PA by using beam dispersion matching. A beam transport simulation with the TRANSPORT code was performed to optimize the beam conditions. We also used a beam slit to reduce the momentum spread of the beam itself. As a result, we achieved an improved momentum resolution of p/∆p ∼ 5,000 for

12

C+

⁴

He (E

4He,lab

= 120 MeV) elastic scattering.

PACS numbers: 29.30.Aj, 29.27.Eg, 29.27.Fh, 25.70.Hi

Keywords: Magnetic spectrograph, Dispersion matching, Beam transport, TRANSPORT code, Charged particle spectroscopy

∗E-mail: [email protected]

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