短寿命核分離加速実験 @KEK-JAERI

素核研、物理第 4 研究系、石山博恒

•Facility Plan

• Research Subjects

• R&D’s and Schedule

Research Subjects

1. 天体核物理　★天体核反応率の直接測定　★ r過程原子核の質量測定　　⇒宇宙での元素合成の実験的

解明

2. 中重中性子過剰核の原子核物理　★クーロン励起、レーザーによ

る核分光　⇒安定核領域から離れた原子核

の各構造、核反応機構

　

3.　物質科学　★ RNBの打ち込みによる材料研究（拡散、電気磁気物性、機械的性質）

　⇒新材料の探索

4.　超アクチノイド元素の核化学と原子核物理

　★超アクチノイド元素の化学的性質の研究

　★超重元素探索とその構造

Facility Proposal

1999 - 2000: All the RNB instruments were moved to Tsukuba(no-primary beam accelerator)

To rapid resume “Low-Energy RNB Science” including the nuclear physics, nuclear chemistry, nuclear astrophysics, material science, etc.

It would be too late to start E-arena in JHF, whose construction will take at least 6-7 years!!

KEK-JAERI Joint RNB Facility • 5-9 MeV/u RNB will be available with using the existing S.C. Linac

• Neutron-rich medium- and heavy-RNB can be supplied by the

help of p-induced U-fission reaction.

• Intense stable nuclear beam is also available independent from Tan

dem

• Low Energy RNB center under the collaboration with KEK and JAERI

Time Schedule

2000 2001 2002 2003 2004 2005

KEK

　 Charge Breeder

　 Beam line

　 Linac

　 Measuring device

　 Water

　 Buncher

JAERI

　 IH-2、 HEBT

　 Exp. Room

　 Utility house

　 Electric power

　Water cooling system

(< 1 MeV/u)

(5-9 MeV/u)

Charge Breeding(CB-) ECR

Accelerator condition: A/q≥30 for SCRFQ, ≥10 for IH1, ≥7 for IH2, SC-linac

MINIMAFIOS (10 GHz) ECRIS1+ ->n+ breeding efficiency

DC-breeding/Bunching BreedingECR confinement time: 520 ms for Rb15+

Charge states equibration time: ~20 msN. Chauvin et al.,Proc. 14th ECRIS99(‘99)151.

1+-I/S ISOL CB-ECRIS

Particle production

to SCRFQ

1+-ion n+-ion

Ele

ctri

c po

tent

ial (

V)

V(~10 eV)

VCB=2A/q kV

smooth deceleration sudden deceleration

ECR ion source for Charge Breeding

(12GHz)

1st ECR ion source (2.45GHz)

1st Analyzing Magnet

2nd Analyzing Magnet

FC-1 Slits

FC-2

QT

Einzel lens

QD

Deceleration systemEizel lens

QD

TMP

TMP

TMP

TMP

TMP

0 1 2

m

Layout of Layout of the Charge Breeding Systemthe Charge Breeding System　　 at at KEK Test BenchKEK Test Bench

0

20

40

60

80

100

1 2 3 4 5 6 7 8

with 1+ion injectionwithout 1+ion injection

Charge State

Charge distribution of Ar

Cu

rren

ts (

pn

A)

Li+

Charge-discharge mechanism in Li Battery

Li

C6Lix(Cathode) Li1-xCoO2(Anode)

8Li density

position

counts

E

=(2Dt)1/2

T=t0

t1

t2

短寿命核ビームによる固体試料中の拡散系数測定

特徴特徴

1.高速短寿命核ビーム　⇒表面状態によらない拡散条件

2.遅延荷電粒子エネルギー測定放出エネルギースペクトルの時間変化　⇒密度分布変化

3.Sensitivity短寿命核の寿命と遅延荷電粒子の阻止能　⇒ on-Line測定（大きい拡散系数）

Explosive Nucleosynthesis

p

n

D

3He

T

4He

6Li 7Li

7Be

8B

9Be

10B

11C

10Be 11Be

11B 12B

12C 13C 14C

13N 14N 15N

15O 16O

15C

16N

17O 18O 19O

9Li

10C

12N

13O 14O

6He 8He

11Li

12Be

13B 14B 15B

16C 17C

17N 18N 19N

20O 21O 22O

17F 18F 19F 20F 21F 22F 23F

8Li

Neutron

Pro

ton

STABLE DECAY

T9 = 1 ( 109 K )

Supernova Explosion

(,n) reaction Core

T9=10Neutron & Proton

T9=3Alpha & Neutron

T9=1Neutron & Seed

-process

r-process

E=1~2 MeV/uI=103～ 105pps

Direct-Exclusive Measurement of (α,n) reaction

RN beam

Detector

MSTPC & Neutron counter

Energy region

T9 ～ 1

Ecm ～ 0.5MeV

MCP Start counter (PPAC)

Veto counter(SSD)

MSTPC

He gas

Neutron counter

n