Neutron Neutron Source ces PART 2 PART 2 Chris istin ine - PowerPoint PPT Presentation

Neutron Neutron Source ces PART 2 PART 2 Chris istin ine Darve European Spallatio ion Source ce CD – Neutrons Sources ASP2012 – July 31 th , 2012

Outline PART 1 Background for neutron course • Neutrons properties and their interactions • Applications using Neutrons • PART 2 How to generate intense neutron beams • High power proton linear accelerator • PART 3 Examples of world-wide neutron sources • CD – Neutrons Sources ASP2012 – July 31 th , 2012 - 2 -

High time average and peak flux Evolution of the performance of neutron sources ESS 10 20 Effective thermal neutron flux n/cm 2 -s SNS ISIS ILL HFIR J-PARC NRU MTR 10 15 IPNS NRX HFBR ZINP-P / FRM-II WNR KENS SINQ X-10 ZINP-P 10 10 CP-2 CP-1 Berkeley 37-inch cyclotron 10 5 350 mCi Steady State Sources Ra-Be source Pulsed Sources 1 Chadwick 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020 (Updated from Neutron Scattering , K. Skold and D. L. Price, eds., Academic Press, 1986) CD – Neutrons Sources ASP2012 – July 31 th , 2012

Examp mple of the ESS acce ccelerator Nomin minal Upgr grade de Average beam power 5.0 MW 7.5 MW Macropulse length 2.86 ms 2.86 ms Repetition rate 14 Hz 14 Hz Proton energy 2.5 GeV 2.5 GeV Beam current 50 mA 75 mA Duty factor 4% 4% Beam loss rate < 1 W/m < 1 W/m Functional Requirements: • Capacity to transfer energy from RF system to the beam, • Capacity to confine the protons longitudinally, • Capacity to steer the protons longitudinally, CD – Neutrons Sources ASP2012 – July 31 th , 2012

The ESS accelerator • Single pass linear accelerator • Normal conducting - Electron cyclotron resonance source - Radio-frequency quadruple (RFQ) - Drift tube linac • Superconducting - Double spoke resonator - Elliptical cavities (medium beta and high beta) CD – Neutrons Sources ASP2012 – July 31 th , 2012

Proton source ce CD – Neutrons Sources ASP2012 – July 31 th , 2012

Proton source ce & LEBT 7 CD – Neutrons Sources ASP2012 – July 31 th , 2012

T ank machining at Cinel (Vigonza-Italy) CD – Neutrons Sources ASP2012 – July 31 th , 2012

SC. Spoke Resonator and d Ellip iptica ical Cavit itie ies Spoke Resonator Elliptical Cavities Cavity RF parameters R/Q 426 W G 130 W Q o at 4K 2.6 10 9 Q o at 2K 1.2 10 10 E pk / E acc 4.43 B pk / E acc 7.08 T uning system Power coupler 9 CD – Neutrons Sources ASP2012 – July 31 th , 2012

CD – Neutrons Sources ASP2012 – July 31 th , 2012 10

Cryo yomo modu dules CD – Neutrons Sources ASP2012 – July 31 th , 2012 11

CD – Neutrons Sources ASP2012 – July 31 th , 2012 12

HEBT, ma magn gnets and d power supplie ies • Several optical designs of the High Energy Beam Transport system have been developed during the evolvement of the ADU project. • The present design fulfill the requirements including layout geometry and the 6 × 16cm 2 beam footprint on target with a sufficiently low maximum current density to ensure a long target lifetime. • The technologies to be used for building the magnets and power supplies have been studied including aspects of handling and optimization of power consumption. • The issues in 2012 consist of completing the many details to go into the TDR coherently with the other work packages, including costing CD – Neutrons Sources ASP2012 – July 31 th , 2012

RF sys ystems ms • Main in Features – One RF power source per resonator – RF Sources • Main in Challenge ges • Pulsed cathode klystrons for – Large number or resonators (>200) elliptical, DTL, and RFQ – Large beam loading (Q L < 7x10 5 ) • Gridded tube for spokes (IOTs) – Large Lorentz de-tuning (>50 – Two klystrons per modulator for degrees) elliptical – Long Pulse length (3 mS ~3 Lorentz – 30% overhead for RF regulation detuning time constants) • Adaptive low level feed-forward – Large dynamic range in power algorithms and Low gain feedback (elliptical cavities range from 50kW – • High bandwidth piezo tuners on to 900kW) superconducting cavities – Large average power (15 MW of AC – Bundled waveguide stub layout power) CD – Neutrons Sources ASP2012 – July 31 th , 2012

Integr grated d Control Sys ystem m for ESS • Decis cisio ion to have a sin ingl gle in integr grated d co control sys ystem m for ESS – EPICS based – ITER control box concept • Ach chie ieveme ments: – Control Box prototype running at ESS – Naming Convention with tools implemented – Working Development Environment and prototype ESS CODAC – Well defined Safety / Protection system architecture – Parameter List tools developed – Interfaces with the Instrument Controls defined – BLED database for parameters • Issues: Issues: – Target Safety System and Infrastructure Controls requirements immature – Fast data acquisition for Accelerator AND Instruments? – ICS scope not resourced CD – Neutrons Sources ASP2012 – July 31 th , 2012

ESS Instrume ment CD – Neutrons Sources SLHIPP 2 – Catania – May 3 and 4, 2012 ASP2012 – July 31 th , 2012 ESS/AD/CV/Christine Darve 16

Beam m Dia iagn gnostics ics Main topics addressed: modeling codes, radiation issues, longitudinal and transverse measuring techniques Main message: more diagnostic equipment than envisaged ü The primary linac diagnostic needs include be beam m posit itio ion, be beam m arriv ival time ime (or phase), be beam m bu bunch ch lengt gth, be beam m transverse profil iles, and be beam m loss. ü Especially important for high power operation are sensit itiv ive be beam m loss me measureme ment and profil ile resolutio ion over a wide dynamic range. ü T echniques for halo me measureme ment in a superconducting environment need to be developed. 17 17 CD – Neutrons Sources ASP2012 – July 31 th , 2012

Long g Pulse and d co cold d neutrons • Many y research ch react ctors in in Europe are agin ging g and d wil ill be be cl closed d be before 2020 2020 – Up to 90% of the use is with cold neutrons • There is is a urge gent need d for a new high igh flux co cold neutron source ce in in Europe Europe – The vast majority of users will profit from a pulsed structure – A large fraction of the users are fully satisfied by a long pulse source (approx 2 ms, 20 Hz) – Existing short pulse sources (ISIS, JPARC and SNS) can supply the present and imminent future need of short pulse users F. Mezei, NIM A, 2006 14 1,6x10 “Pulsed cold neutrons will always 14 1,4x10 14 1,2x10 300 kj/pulse be long pulsed as a result of the /s/str/Å] 14 1,0x10 2 13 moderation process” Instantaneous brightness [n/cm 8,0x10 13 6,0x10 13 4,0x10 13 2,0x10 0,0 0 500 1000 1500 2000 2500 3000 Time [ µ s] CD – Neutrons Sources ASP2012 – July 31 th , 2012

T arget Station W/He/H 2 TRAM Optimization yielding gains T arget monolith during target change T arget wheel Moderator-reflector plug Accelerator proton beam window CD – Neutrons Sources ASP2012 – July 31 th , 2012

Spallatio ion : ch choice ice of target ma materia ials Y(E,A)=0.1 [A+20] [E (GeV) -0.12)] n/p CD – Neutrons Sources ASP2012 – July 31 th , 2012 - 20 -

CD – Neutrons Sources ASP2012 – July 31 th , 2012 - 21 -