Design Status of the PEFP RCS

Transcription

1 Design Status of the PEFP RCS HB2010, Morschach, Switzerland J.H. Jang 1) Y.S. Cho 1), H.S. Kim 1), H.J. Kwon 1), Y.Y. Lee 2) 1) PEFP/KAERI, 2) BNL (

2 Contents PEFP (proton engineering frontier project) Status Expansion Plan of PEFP Design Concept of the PEFP RCS (rapid cycling synchrotron) Lattice Design and Beam Dynamics Summary 2

3 Overview of PEFP Project : Proton Engineering Frontier Project (PEFP) 21C Frontier Project, Ministry of Education, Science & Technology Project Objectives : 1 st : Developing & constructing a proton linear accelerator (100MeV, 20mA) 2 nd : Developing technologies for the proton beam utilizations & accelerator applications 3 rd : Promoting industrial applications with the developed technologies Project Period : (10 years) Project Cost : B Won (Gov B, Private 12.9 B) (Gyoungju City provides the land, buildings & supporting facilities) 3

4 Schematics of PEFP Linac & Beamlines Future Extension 100 MeV 20 MeV 3 MeV TR105 TR101 TR25 TR21 TR104 TR103 TR102 TR24 TR23 TR MeV Beamlines 20 MeV Beamlines Features of the PEFP linac 50 kev Injector (Ion Source + LEBT) 3 MeV RFQ (4-vane type) 20 & 100 MeV DTL RF Frequency : 350 MHz Beam Extractions at 20 or 100 MeV 5 Beamlines for 20 MeV & 100 MeV - Beam to be distributed to 3 BL via AC Output Energy (MeV) Peak Beam Current (ma) Max. Beam Duty (%) 24 8 Avg. Beam Current (ma) Pulse Length (ms) Max. Repetition Rate (Hz) Max. Avg. Beam Power (kw)

5 Status of Accelerator Development Fully developed & integrated up to 20 MeV at KAERI site in Daejeon The fabrication of tanks up to 91MeV has been finished. Last tank will be fabricated in this fiscal year. Operating Completed 2010 Step 1 ( ~ 05.06) Step 2 ( ~ 08.03) Control & Diagnostics Step 3 ( ~ 12.03) RF RF RF RF RF RF RF RF RF 20~33 33~45 45~57 57~69 69~80 80~91 91~102 IS RFQ DTL21~DTL24 MEBT DTL101 DTL102 DTL103 DTL104 DTL105 DTL106 DTL MeV Beam 100 MeV Beam 5

6 The Project Site The land (440,000 m 2 ) provided by Gyeongju municipal government. (The capital of Shilla dynasty for 992 years, from BC 57 to AD 935.) Seoul Phase I Free Way (Gyeonju IC) KAERI (Daejeon) Daegu Gyeongju Phase II Pusan Express Railway (KTX) (New Gyeongju Station) 6

7 400 m The Site Plan Proton Accelerator Research Center 1 Accelerator Tunnel 2 Experimental Hall 3 Ion Beam Facility 4 Utility Building 5 Substation 6 Cooling Tower 7 Water Storages 8 Main Office Building 9 Regional Cooperation Center 10 Dormitory 11 Information Center 12 Sewage Plant Phase II Phase I (2012 ~) (2002~2012) Express Railway (Under construction) Phase - II Reserved for the Future Expansion 1,100 m 450 m Phase - I Gyeong-bu Freeway 7

8 PEFP 20 MeV Linac Klystron for RFQ 350 MHz 1 MW CW Waveguide WR2300 Klystron for DTL 350 MHz 1 MW CW Target station for user Beam Profile 4cm Extracted first beam (July 2005) Obtained operation license (June 2007) - Avg. current: 0.1 A, - Rep. Rate: 0.1 Hz, 4 hrs/week Started beam service (June 2007) Achieved design performance (May 2008) Injector 50 kev 40 ma LEBT 3 MeV RFQ 350 MHz 4-Vane 20 MeV DTL 4 -Tank 150-DT 8

9 N.O of particles Target Station for 20-MeV beams (at KAERI site) Beam energy / current : 20-MeV, 1uA (average) 20mA peak, 50us, 1Hz Target room dimension : 0.6m(width)x2.6m(length)x1.8m(height) External beam diameter : 10cm (1m transport after beam window) Beam window : 0.5mm thick Al Shielding : gamma-10cm thick lead, neutron 15cm thick concrete License issued at June, 2007 (May, 2008 for 1uA license) 1m Gauss fit of Data1_B Target Data: Data1_B Model: Gauss Equation: y=y0 + (A/(w*sqrt(PI/2)))*exp(-2*((x-xc)/w)^2) Weighting: y No weighting Chi^2/DoF = R^2 = y ± xc ± w ± A ± Lead shielding QM (triplet) X axis [cm] External beam Concrete Shielding Irradiated Samples DTL

10 100-MeV DTL tanks The fabrication of tanks up to 91MeV (DTL101~DTL106)has been finished. Last tank will be fabricated in this fiscal year. tank cell # length (m) energy (MeV) DTL DTL DTL DTL DTL DTL DTL DTL tanks at Gyeonju office 10

11 Beam Lines Designed by reflecting user s requirements Developed components, BM, QM, ACM, & Beam Instruments AC magnet distributes proton beams to three target rooms BL21 BL25 BL22 BL23 BL24 Beam Line Application Field Rep. Rate Avg. Current Irradiation Condition TR21 Semiconductor 60 Hz 0.6 ma Hor. Ext. TR22 TR23 Bio-Medical Application Materials, Energy & Environment 15 Hz 60 A Hor. Ext. 30 Hz 0.6 ma Hor. Ext. TR24 Basic Science 15 Hz 60 A Hor. Ext. TR25 Radio Isotopes 60 Hz 1.2 ma Hor. Vac. BL101 BL102 BL BM Fabricated at IHEP (China) 25 BM Beam Line magnets at Gyeonju office QM AC Dipole BL105 BL104 Beam Line Application Field Rep. Rate Avg. Current Irradiation Condition TR101 Radio Isotopes 60 Hz 0.6 ma Hor. Ext. TR102 TR103 TR104 TR105 Medical Research (Proton therapy) Materials, Energy & Environment Basic Science Aero-Space Neutron Source Irradiation Test 7.5 Hz 10 A Hor. Ext. 15 Hz 0.3 ma Hor. Ext. 7.5 Hz 10 A Hor. Ext. 60 Hz 1.6 ma Hor. Vac. 11

12 Options of PEFP Expansion Two Options Proposed by Science & TEchnology Policy Institute (Feb, 2009) : in a research report on Long-term Planning for Proton Engineering Frontier Project Option 1 1 GeV Linac + Acc. Ring 2 MW Spallation Neutron Source 250, 400, 1000 MeV Proton Beam Option MeV Linac + 2 GeV RCS 0.5 MW Spallation Neutron Source 250 MeV Proton Beam 400 MeV Linac + 8 GeV PS 8 GeV Proton Beam 12

13 Design concept of PEFP RCS Purpose Spallation neutron source: energy > 1GeV Medical application, Radioisotope, Nuclear physics, etc: energy ~ 450 MeV Design concept PEFP 100MeV linac: injector of the RCS Final energy of RCS: 1 GeV (initial stage) Beam power of 60 kw (initial stage) Beam power of 500kW through 3 upgrade stages: Injection: charge exchange and painting Extraction: fast and slow extraction injection and extraction energies, repetition rate 13

14 Upgrade Plan - Injection energy: from 100 MeV to 200 MeV - Extraction energy: from 1 GeV to 2 GeV - Repetition rate: from 15 Hz to 30 Hz Injection Extraction Repetition RF Output Energy Energy Rates Voltage Power (MeV) (MeV) (Hz) (kv) (kw) Initial In the following contents, we will focus on the RCS design study in initial stage 14

15 Design parameters of PEFP RCS (initial stage) Beam power (kw) : 60 Injection energy (MeV) : 100 Extraction energy (MeV) : 1000 Injection type : Charge exchange Extraction type : Fast & Slow Repetition rate (Hz) : 15 Circumference (m) : Lattice structure and cell number : FODO and 20 Number of dipole : 32 Dipole field at 1 GeV (T) : 0.56 Super-period : 4 Tunes of Q X /Q Y : 4.39/4.29 T : 4.4 RF harmonic number : 2 Required RF voltage : 75 kv 15

16 RF Acceleration Lattice Design (1/2) Injection Four-fold symmetry : To reduce lower-order resonance FODO lattice : pseudo 20 fold symmetry m RF Acceleration Dispersion free long straight sections : Injection and Extraction RF system Collimator Momentum Collimation Lattice Structure of PEFP RCS Collimator Fast Extraction Slow Extraction Arc straight sections with missing dipole : Momentum collimation Slow extraction 16

17 Lattice Design (2/2) beta functions and dispersion function in one super-period Lattice: FODO Beam optics: MAD8 - dispersion suppression in the straight sections Maximum beta functions: 18.3 m / 18.7 m Dispersion function < 6.0 m Physical acceptance: 560 mm-mrad Collimator acceptance: 350 mm-mrad Transverse emittance: 280 mm-mrad 17

18 Closed Orbit Distortion and Correction MAD8: MICADO method Number of used BPM : 40 Number of used corrector magnets : 40 Maximum orbit distortion before/after corrections : ±10mm / ± 1mm Statistical analysis to determine the specification of the corrector magnets. Parameters Magnetic Field Error of BM Magnetic Field Error of QM Displacement Error Rotation Error Values (db/b) =10^-4 (db/b) =10^-4 dx = dy = ds= 0.3mm d x, d y, d z = 1.0 mrad 18

19 Chromaticity Correction Natural chromaticity: / Assuming momentum spread : ±1% Maximum tune spread due to chromaticity: dqx = 0.043, dqy = (This is very small compared with the space charge tune shift of 0.2) Horizontal Vertical 19

20 Dynamic Aperture Study DYNAP routine in MAD8 Tracking Method: LIE Algebra Method p/p < 0.7 % ( Injection Simulation Result ) Closed Orbit Distortion Effects Multipole Effects of Dipole Magnet Most dominant effects: COD (After correction, DA is larger than the stable region) COD effects p/p effects 20

21 Injection Painting scheme: Correlated Macro particles number: 4.0*10 4 Circumference [m] : Linac peak current [ma] : 20 Injection energy [MeV] : 100 Injection time [ms] : Machine tunes(qx/qy) : 4.39/4.28 Foil Thickness : 200 μg/cm 2 Linac emittance [pi mm mrad] : 1.0 Number of Turns Injected : 200 Beam emittance [pi mm mrad] : 280 Space Charge effect : YES 21

22 Transverse Correlated Painting correlated painting: ORBIT code Spatial beam size of horizontal and vertical coordinate: 55mm f ( t) 1 t t injection x-y bump function distribution y-y x-x 22

23 Acceleration Simulation (1/3) Time structure of the RCS input beam: injection energy: 100 MeV repetition rate: 15 Hz Linac beam just before injection : One macro-pulse includes 400 mid-pulses ( h=2 ) [ Macro-Pulse ] [ Mid-Pulse ] RCS beam just after injection : One pulse includes two bunches bunch length of 500 ns ~ Chopping factor of 57% [ Pulse ] [ Bunch ] 23

24 Acceleration Simulation (2/3) - This simulation is for the initial stage: ORBIT - Magnetic field ramping: sinusoidal - Peak accelerating voltage < 75 kv - Synchronous phase < 35.3 particle distribution in longitudinal phase space magnetic field ramping 75.0 kv Energy 18.7 kv peak voltage Phase - Energy ( E): Gaussian with = 0.2 MeV - Phase ( ): uniform in 103 degrees ( chopping factor = 57%) sync. phase 24

25 Acceleration Simulation (3/3) - final energy = 1003 MeV - final capture rate = 99.9 % 200 turns (100.1 MeV, 100 %) 2000 turns (113.8 MeV, %) 6000 turns (210.5 MeV, %) turns (362.5 MeV, %) turns (700 MeV, %) turns (1003 MeV, %) 25

26 Summary RCS is an option for PEFP expansion. 1 GeV RCS with the 100MeV linac as an injector - upgradable up to 2 GeV (STEPI result for PEFP future study) - fast extraction for spallation neutron source - slow extraction for medical application, RI facility, nuclear physics - lattice design, beam dynamics calculation including acceleration : MAD, ORBIT Further work - 2GeV study with 200 MeV injection. - beam transport line (linac to RCS, RCS to target) and extraction - components design - instability issues, slow extraction, etc. 26

27 Thank you for your attention!! 27