UPGRADE OF THE LENS/NREP PROTON LINAC: COMMISSIONING AND RESULTS

Transcription

1 UPGRADE OF THE LENS/NREP PROTON LINAC: COMMISSIONING AND RESULTS Barbara vo Przewoski HEART 2008 Distributio statemet A: Aroved for Public Release, Cotract # N

2 Outlie What is NREP? Curret status Desig goals. Ugrades. Neutro flux Coclusio. Distributio statemet A: Aroved for Public Release, Cotract # N

3 LENS/NREP LENS/NREP is a accelerator drive ulsed eutro source. Neutros are geerated i low-eergy (, x) ) reactios (E( <13MeV) i Beryllium. 9 Be+ ( ( )+ x Protos are rovided by a liear accelerator. LENS rovides cold eutros for materials research, eutro hysics ad techology ad NREP rovides eutros i the thermal to MeV eergy rage for eutro radiatio effects research. The beam has a variable ulse width (from ~10 μs s to ~1.4 ms). Dedicated beamlies devoted to materials research ad eutro radiatio effects research are available. Distributio statemet A: Aroved for Public Release, Cotract # N

4 Neutro Outut from Be as a fuctio of roto eergy Assumed LINAC oeratig oit 16 ma/ 0.8 ms.w./1% duty cycle Yield at 13 MeV ~ /mc DUT as close to target as ossible Fluece over 4 i er LINAC ulse = 1x10 14 /mc x 16 ma x.0008 s = /ulse Neutros/cm 2 er 1 cm from target = / (4 i) = 8x10 10 /cm 2 /ulse 13 ulses/s Sadia SPR III reactor, 6x10 14 /cm 2 /ulse, 2 ulses/h Distributio statemet A: Aroved for Public Release, Cotract # N

5 IUCF facility layout Distributio statemet A: Aroved for Public Release, Cotract # N

6 LENS/NREP layout Distributio statemet A: Aroved for Public Release, Cotract # N

7 timelie Dec 2004 first eutros Dec 2005 first ublished data (Dyer) Dec 2006 ew klystro RF system Ju d beamlie Dec 2007 ew DTL (13 MeV) Distributio statemet A: Aroved for Public Release, Cotract # N

8 1 st Target uder costructio (Nov 04) Device uder test Distributio statemet A: Aroved for Public Release, Cotract # N

9 Milestoes 14 Dec 2004 First roto beam first eutros 21 Dec 2006 Klystro commissioig 11 ma roto curret Distributio statemet A: Aroved for Public Release, Cotract # N

10 Dec 2007: New ACCSYS DTL existig ios existig RFQ existig DTL 7 MeV 13 MeV Distributio statemet A: Aroved for Public Release, Cotract # N

11 February 2008 Istall klystro ower for ew DTL Distributio statemet A: Aroved for Public Release, Cotract # N

12 LENS Power Ugrade Path Goal: higher average ower of a roto beam, delivered to the target Ugrade Klystro istallatio Beam Eergy Beam Curret Beam Duty Power, Peak/Av Neutro Rate 7 MeV 25 ma 0.6% 175/1 kw /s New DTL sectio 13 MeV 25 ma 1% 325/3 kw /s New ower suly for klystro tubes New ijector ad RFQ 13 MeV 25 ma ~2.5% 325/8 kw /s ////////////////////////////////////////////ot fuded////////////////////////////////////////// 13 MeV 50 ma ~2.5% 650/16 kw /s Distributio statemet A: Aroved for Public Release, Cotract # N

13 RF System Ugrade Peak curret Old RF System With Klystros 10 ma 25 ma Duty Factor 0.4% 0.6% Mi Pulse Legth Max Pulse Legth Beam Imrovemets 50 µsec 10 µsec 150 µsec 300 µsec Distributio statemet A: Aroved for Public Release, Cotract # N

14 Accelerator Ugrade A ew DTL sectio desiged by AccSys Techology Ic. DTL Parameters Beam Parameters Iut eergy 7 MeV Iut eergy 7 MeV Outut eergy 13 MeV Outut curret 50 ma Outut eergy 13 MeV Outut curret 25 ma Beam trasmissio at 50 ma 100% Beam trasmissio at 50 ma 100% Duty Factor 6% Beam Duty Factor 2.5% Peak RF ower at 50 ma 750 kw Peak RF ower at 50 ma 750 kw Distributio statemet A: Aroved for Public Release, Cotract # N

15 Beamlie Ugrades Both beamlies feature a oliear beam sreadig system to make a beam uiformly distributed over the target surface Cold Neutro Target 7MeV 25mA df 0.02% NRERP target 7MeV 25mA df 0.6% Distributio statemet A: Aroved for Public Release, Cotract # N

16 Beehive Be target H 2 O reflector Polyethylee i eoxy Proto beam Lead shot i eoxy Distributio statemet A: Aroved for Public Release, Cotract # N

17 Beryllium target Proto beam 1 Mout 2 Be Target 15 X 9 cm 2 3 mm thick High beam ower Thermal stress Mechaical stress MAX 650 W/cm % >1 kw/cm 2 Gauss σ x =σ y =0.5 cm % ~5 kw/cm 2 Gauss σ x =σ y =0.5 cm % >1 kw/cm 2 Gauss σ x =σ y =1.5 cm Make a beam uiformly distributed over ~ 9 X 9 cm 2 Distributio statemet A: Aroved for Public Release, Cotract # N

18 Beam damage to viewer Distributio statemet A: Aroved for Public Release, Cotract # N

19 Remedy: No-liear exasio Focus beam tails, but do t t chage core Sigle octuole focuses i laes ad defocuses o diagoals Combie two octuoles o-liear tail foldig Distributio statemet A: Aroved for Public Release, Cotract # N

20 Magetic octuoles Force: v F v q v = qe + ν c v B Multiole exasio: B( x) = b b ! x b x 2! b x 3!... Octuole term: B ( x) = b x 3 3 3! Distributio statemet A: Aroved for Public Release, Cotract # N

21 Foldig with Octuole Distributio statemet A: Aroved for Public Release, Cotract # N

22 Simulatio X histogram Y histogram XY sace Octuoles ON Octuoles ON Octuoles OFF Octuoles OFF Distributio statemet A: Aroved for Public Release, Cotract # N

23 Diagostics: HARPs Wire diameter ~ 20μm HARP_01 HARP_02 HARP_01 Wire sacig, mm Area covered, mm*mm H: 2 V: 2 32 X 32 H: 9c 2.5, 6o - 5 V: 11c 0.4, 2m 0.5, 4o X 50 Distributio statemet A: Aroved for Public Release, Cotract # N H: 6 V: 6 90 X 90

24 Diagostics: Viewer Beryllium Oxide 4 ieces 1'x1 ea Distributio statemet A: Aroved for Public Release, Cotract # N

25 Use CID camera to moitor viewer Subtract backgroud Smoothig/Average Sa Picture Record Image Beam Profile Distributio statemet A: Aroved for Public Release, Cotract # N

26 Beam arameters: 2 ma 7 MeV 10 Hz 10 µsec CID Octuoles OFF Octuoles ON Octuoles ON Distributio statemet A: Aroved for Public Release, Cotract # N

27 Calculated sectra 3,7,13 MeV 3 MeV 7 MeV 13 MeV I(E) (/sr/uc/mev) 1.E+15 1.E+14 1.E+13 1.E+12 1.E+11 1.E+10 1.E+09 1.E+08 1.E+07 1.E+06 1.E+05 Vary edoit! 1.E+04 1.E-09 1.E-08 1.E-07 1.E-06 1.E-05 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 Neutro Eergy (MeV) Distributio statemet A: Aroved for Public Release, Cotract # N

28 Positio deedece (MCNPX) thermal Folded w/ Si damage fuctio Distributio statemet A: Aroved for Public Release, Cotract # N

29 TOF measuremet Distributio statemet A: Aroved for Public Release, Cotract # N

30 Measured eutro flux (old RF system) 7.3 ma eak, 150 μs ulse width, 30 Hz re rate (Oct 2005) Thermal, < 0.55 ev,, Au, I, 3 He Fast, > ~3 MeV,, Ni, S 1 MeV equiv., 2N2222A measured 10 7 /s/cm / / / MCNP 10 7 /s/cm Ni, S ad Au, I, 3 He measuremets agree Measured flux is ~25-45% lower tha redicted Gamma dose egligible (TLD: 1.5 krad i 24h) Distributio statemet A: Aroved for Public Release, Cotract # N

31 detector couts Neutro flux measuremets 0 6/6/05 12:00 6/7/05 0:00 6/7/05 12:00 6/8/05 0:00 date ad time Moitor detectors 3He detector gamma boer Ni Au & Au(Cd) S 2N2222As Ni S Ni Au & Au(Cd) Ni EBT film TLDs S Distributio statemet A: Aroved for Public Release, Cotract # N

32 Thermal eutro bit cross-sectios sectios Dyer et al., IEEE 53,7 (2006) TRIUMF 2005 Idiaa 2005 NPL Bit cross-sectio (cm 2 ) Mfr B - dev 2a 1Mfr B - dev 2b Hitachi A Toshiba Mitsubishi Samsug B Mfr B - dev 1 Hitachi B Distributio statemet A: Aroved for Public Release, Cotract # N Toshiba A Mfr C Mfr A

33 Projected itesity Beam eergy, MeV Peak curret, ma Pulse width, μs Duty factor, % N-flux (/s/cm 2 ), 1MeV equiv Achieved < L < < f < Goal Distributio statemet A: Aroved for Public Release, Cotract # N

34 Coclusios Istallatio ad commissioig of the klystro based RF system is comleted. Neutro flux has bee measured Ugrade of the high voltage suly for the klystro tubes is uder way. Istallatio of the 13 MeV 50 ma DTL is comleted. Come to full oeratio with 25 ma 13 MeV 2.5% beam delivered to either target i Distributio statemet A: Aroved for Public Release, Cotract # N