蓄積リングによる不安定核の質量精密測定と元素合成

クォーク・核物質研究部門

山口 貴之（クロスアポイントメント）
埼玉大学 理工学研究科

2018年6月4日 宇宙史センター構成員会議

RI Beam Storage Rings
Worldwide in Operation

ESR@GSI, Germany

CSRe@IMP, China

Rare-RI Ring@RIBF

A storage device
Many/Singleions

Revolution

High resolution

真空パイプ

High charge state2018

Firsof Rt stora 199
I be ge
2am

Milestones

FAIR
2024/25

Our 5 years

Firs
ma t 20
sse
11s
201
2

ESR

HIAF
2020

Construction/Commissioning Phase

RIBFのRIビーム強度は世界一

201

Rare-RI Ring

8CSRe

Production Phase2018

Milestones
Firsof Rt stora 199
I be ge
2am

FAIR2024/25

Construction/Commissioning Phase

MS01
MS02
Jun. 2015 Dec. 2015

78KrFirst storagealpha particles

48CaMS03
Nov. 2016MS04
Nov. 2017

238U238U

OEDO
Construction

8201

Rare-RI RingFirs
me t massasure.

Construction2012 - 2013

HIAF2020

CSReFirs
tof R storag
I bee
am

Our 5 years

Firs
ma t 20
sse
11s
201
2ESR

Production Phase

RI Beam Factory in RIKENECRØ Maximum energy is 350 MeV/u
Rilac
for heavy ions up to U ions.
Ø Goal beam intensity is 1 pµA CSM

PTEP 2012, 03C002

Table 1. Specifications of the RIBF cyclotrons. In the bottom row, the number of acceler
ation cavities is shown (FT = flat-topping cavity).

Rilac2AVF

RRC

2, 03C002

H. Okuno et al.

fRC

fRC

IRC

SRC

570
42.1
1054.75
2 + FT

980
41.5
20
18–38
2 + FT

2600
61.5
4 + 22
18–38
4 + FT

K-value (MeV)
Number of sectors
Velocity gain
Number of trim coils
Frequency range (MHz)RF system

fRC

IRC

SRC

570
42.1
1054.75
2 + FT

980
41.5
20
18–38
2 + FT

2600
61.5
4 + 22
18–38
4 + FT

SRC

Table 1. Specifications of the RIBF cyclotrons. In the bottom row, the number of accelertion cavities is shown (FT = flat-topping cavity).

K-value (MeV)
Number of sectors
Velocity gain
Number of trim coils
requency range (MHz)RF system

H. OkBigRIPS
IRC
Downloaded from http://ptep.oxfordjourna

Fig. 3. The ring cyclotrons in RIBF. The fRC, IRC, and SRC have been newly constructed for the RIB

Rare-RI Ring: R3

A dedicated device for precision mass measurements
Rare RI:
Very low production rates, ~1/day
Short lived nuclides, ~msOEDO-SHARAQBigRIPSWhat is new?
pulse mode
operationsynchrotron

periodic bunched pulses

storage ringindividualinjection

cyclotron

random particles

storage ring

測定したい稀少なRIだけ選び出せるHow to inject beam into R3

Isotope-Selectable Self-Triggered Injection (ISSI)BigRIPSF3

１個ずつ入射するために、キッカー電磁石の動作が間に合うか問題

KickerFirst storage of 78Kr beam

Single ion storage

薄膜検出器
周期的なパルス

キッカー入射(Start)Isochronous Mass Spectrometrym0
T0 = 2qB<latexit sha1_base64="1cG2uFl1BzjMjyXJdv3dj4EvVow=">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</latexit>
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sha1_base64="mbefhOTxt4d5zW+kx65yi8G20W8=">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</latexit>

基準の粒子(m0)に対して等時性に調整する
測定粒子は厳密には等時性ではないため速度の補正が必要(Stopand PID)

First Mass Measurement
With known massess

238U 345 MeV/u → 78Ge 168 MeV/u fission fragments

hronouoc79As

is

原子番号Z

RIビーム粒子識別78Ge77Ga

76Zn

All events at F3Ext. events

75Cu

N = 46

質量数/原子番号 A/Z
D. Nagae

等時性粒子の78Geは運動量によらずに周期一定

First Mass Measurement
With known masses
238U 345 MeV/u → 78Ge 168 MeV/u fission fragments⎛ m ⎞ ⎛ m ⎞ T1⎜⎜ ⎟⎟ = ⎜⎜ ⎟⎟⎝ q ⎠1 ⎝ q ⎠0 T0D. Nagae

1 − β12⎛ T1 ⎞1 − ⎜⎜ β1 ⎟⎟⎝ T0 ⎠2yranimilerP⎛ m ⎞ ⎛ m ⎞ T1⎜⎜ ⎟⎟ = ⎜⎜ ⎟⎟⎝ q ⎠1 ⎝ q ⎠0 T0

1 − β12⎛T ⎞1 − ⎜⎜ 1 β1 ⎟⎟⎝ T0 ⎠2補正のためのβの出し方が大事
D. Nagae, S. Omika

m/q accuracy ~ several x 10-6

Single ion storage

いかに等時性がよく成り立っているか

F. SuzakiFirst long time storage of RI beam: 6 sec

Storage-ring mass
spectrometry• For rare isotopes: low production rates/short livedi) High eﬃciencyii) Single ion sensitivityiii) High resolution

Single ions

Atomic Mass Evaluation 2016 publishedChin. Phys. C 41 (2017) 03002, 03003.

030001-3

Mass Precision(NUBASE 2016)

Potential for new masses with R3
Present condition
238U 50 pnA
Latest R3 condition
78Ni 10 → 3 days
(NP1612 estimations)

Z

78Ni

N

238U → 1000 pnA

What will happen?

今後の予定• H30年度、秋から実験スタート
i.中性子過剰Ni同位体の質量 (74Ni~)
ii.中性子過剰A~130: Rh, Pd, Agの質量

R3 collaborationin 2015