Possible Participation of UNIST at Korea in AWAKE Experiment Moses Chung, Ulsan National Institute of Science and Technology AWAKE CERN Dec. 11~12, /12/20141Moses Chung | UNIST for AWAKE CERN UNIST 12/12/2014Moses Chung | UNIST for AWAKE2 ? Accelerator Projects in Korea 12/12/2014Moses Chung | UNIST for AWAKE3 RISP (Korea Heavy-Ion Medical Accelerator)(Proton Engineering Frontier Project) (Rare Isotope Science Project) (Pohang Light Source)(Pohang Accelerator Lab. X-Ray Free Electron Laser) KOMAC UNIST OperationalCommissioning in late 2015 OperationalUnder construction ~500 km A New Ambitious University in Korea 12/12/2014Moses Chung | UNIST for AWAKE4 [http://] Focused Research Areas 12/12/2014Moses Chung | UNIST for AWAKE5 [http://physics.unist.ac.kr] 6 faculty members: Best Plasma and Beam physics program in Korea Possible Collaborators 12/12/2014Moses Chung | UNIST for AWAKE6 Beam/Plasma Diagnostics Beam Experiments PIC Simulations Laser-Plasma PIC Simulations + Low temp. discharge Fusion Plasma Diagnostics + (Hae-June Lee) My Short Resume 12/12/2014Moses Chung | UNIST for AWAKE7 - Ph. D. in Plasma Physics (Princeton University) - Postdoc/Peoples Fellow (Accelerator Physics Center, Fermilab) - Selected Publications: S. G. Arutunian, A. E. Avetisyan, M. A. Davtyan, G. S. Harutyunyan, I. E. Vasiniuk, M. Chung, and V. Scarpine, Large Aperture Vibrating Wire Monitor with Two Mechanically Coupled Wires for Beam Halo Measurements, Physical Review Special Topics on Accelerators and Beams 17, (2014). M. Chung et al., Pressurized H2 RF Cavities in Ionizing Beams and Magnetic Fields, Physical Review Letters 111, (2013). H. Qin, R. C. Davidson, M. Chung, and J. W. Burby, Generalized Courant-Snyder Theory for Charged Particle Dynamics in General Focusing Lattices, Physical Review Letters 111, (2013). M. Chung, E. P. Gilson, R. C. Davidson, P. C. Efthimion, and R. Majeski, Use of a Linear Paul Trap to Study Random- Noise Induced Beam Degradation in High-Intensity Accelerators, Physical Review Letters 102, (2009). H. Qin, M. Chung, and R. C. Davidson, Generalized Kapchinskij-Vladimirskij Distribution and Envelope Equation for High- Intensity Beams in a Coupled Transverse Focusing Lattice, Physical Review Letters 103, (2009). M. Chung, E. P. Gilson, M. Dorf, R. C. Davidson, P. C. Efthimion, and R. Majeski, Experiments on Transverse Compression of a Long Charge Bunch in a Linear Paul Trap, Physical Review Special Topics on Accelerators and Beams 10, (2007). 12/12/2014Moses Chung | UNIST for AWAKE8 Beam Physics with Linear Paul Trap of Metal Ion Plasmas Paul Trap Analogy Moses Chung | UNIST for AWAKE9 Intense Beam Propagating through Periodic Focusing Quadrupole Magnetic Field Self-field potential Nonneutral Plasma Trapped in Time Varying Quadrupole Electric Field Focusing coeff. Self-field potential Focusing coeff. 12/12/2014 Paul Trap Simulator Experiment 12/12/2014Moses Chung | UNIST for AWAKE10 Pressure ~10 -8 Torr Trap Time 1~100 ms Density 10 5 ~10 6 cm -3 Axial beam energy 3 ~ 9 eV End Electrodes (DC) 36 ~ 150 V Central Electrodes (AC) f 0 < 100 kHz, V 0 < 400 V rwrw Dry roughing pump TMP Baking jacket Ion source Charge collector Electrode Driver Side view End view DC 40 cm 2L = 2 m r w = 10 cm z DC Electrode, Ion Source, & Charge Collector 0.8 cm Flexibility in applying voltage waveform Voltage amplitude: magnet strength Frequency: magnet spacing Increasing extraction voltage (Ve) creates ions with space-charge effects Sensitive electrometer with LabVIEW interface (~ 1 fC) Measures average Q(r) or n(r) Aluminosilicate Cs emitter Gold-plated stainless steel electrode 10 cm Pierce, Accel, Decel grids 12/12/2014Moses Chung | UNIST for AWAKE11 Compact Barium Ion Source 12/12/2014Moses Chung | UNIST for AWAKE12 Successful Initial test Laser Induced Fluorescence 12/12/2014Moses Chung | UNIST for AWAKE13 Low initial target metastable population Strong background light from glowing barium ion source Studies of Random Noise Effect 12/12/2014Moses Chung | UNIST for AWAKE14 Experiment with 1% uniform white noise Experimental verification of noise effects in high-intensity accelerator has been made in the PTSX device, by adding small random ripple on the voltage waveform [M. Chung et al, Phys. Rev. Lett. 102, (2009)] Emittance Growth 12/12/2014Moses Chung | UNIST for AWAKE focusing periods ExperimentSimulation Linear increase with the amplitude and duration of the noise [M. Chung et al, Phys. Rev. Lett. 102, (2009)] 12/12/2014Moses Chung | UNIST for AWAKE16 Proton Beam Interactions with Gas-Filled Cavity Ionization Cooling Moses Chung | UNIST for AWAKE17 Ionization cooling works within lifetime of muon (2.2 s) Beam passes though absorbing material, losing energy RF cavities replace lost longitudinal momentum Repeated many times, reduces emittance in transverse dimension (4D cooling) 12/12/2014 Absorbers RF Cavities SC magnets Unusual Channel Configuration 12/12/2014Moses Chung | UNIST for AWAKE18 Transverse momentum before cooling absorber Transverse momentum after cooling absorber becomes smaller due to ionization energy loss process beam Absorber RF cavity Magnet After decay & collection Longitudinal momentum is regained by RF cavity RF cavity is embedded in strong B field (> 2 T) Excluding SCRF Beam envelop Achievable smallest transverse beam phase space is determined by focus strength ( ) and Z & A of cooling absorber Windows A Problem Moses Chung | UNIST for AWAKE19 Experimental the 805-MHz Pillbox cavity 25 MV/m at 3 T 12/12/2014 High-Pressure Gas-Filled RF Cavity 12/12/2014Moses Chung | UNIST for AWAKE20 Metallic breakdown Gas breakdown Operation range for Ionization Cooling (10 to 30 MV/m) Combine absorber and RF cavity We identify gas and electrode breakdown regions We confirm RF cavity works in the magnetic field What happens when there is an ionizing beam? 805 MHz cavity RF in Pickup Paschens Law HPRF cavity: What happens with beam? Moses Chung | UNIST for AWAKE21 E RF Evacuated cavity + + ________ _ E RF Gas-filled cavity H 2 H e - (Ionization) + + ________ 12/12/2014 HPRF cavity: Beam test setup 12/12/2014Moses Chung | UNIST for AWAKE22 1: Beam pipe, 2: multi-wire detector, 3: Titanium window, 4: Chromox-6 scintillation screen, 5: First beam collimator, 6: Superconducting solenoid Long C-magnet 1 pulse/min HPRF cavity: Primary results 12/12/2014Moses Chung | UNIST for AWAKE23 DA: Dry Air Beam induced plasma will be shaken by RF electric field and transfer energy from cavity to gas (electrons are main contributors) Electrons may recombine with positive ions, however this process is not fast enough and there is too much energy loss (plasma loading) Addition of an electronegative dopant gas sucks up electrons quickly, greatly decreasing energy loss Remaining positive ions continue to load cavity, but do neutralize, albeit slowly [M. Chung et al, Phys. Rev. Lett. 111, (2013)] HPRF cavity: Theory vs Experiment 12/12/2014Moses Chung | UNIST for AWAKE24 [M. Chung et al, Phys. Rev. Lett. 111, (2013)] HPRF cavity: Outlook 12/12/2014Moses Chung | UNIST for AWAKE25 Plasma loading can be less than beam loading with the addition of electronegative gas for muon cooling channel parameters For intense muon beams, many additional effects should be taken into account ~10 12 /bunch ~10 21 /cm 3 ~10 16 /cm 3 Beam-Plasma Interactions in HPRF Cavity 12/12/2014Moses Chung | UNIST for AWAKE26 Ionizing beam creates plasma column along the beam path - how the plasma counteracts to the beam ? Good or Bad ? Dynamics is totally different from plasma wakefield accelerators X (m) Plasma electrons Beam (mu-) Plasma density ~ Beam density Plasma freq. >> Collision freq. X (m) Beam (mu-) Plasma electrons Plasma density >> Beam density Plasma freq. 0.1) With Profs. H.K. Park, W.C. Lee 12/12/2014Moses Chung | UNIST for AWAKE33 Only parallel components are focused ~ 4 cm diameter port Scattering system 12/12/2014Moses Chung | UNIST for AWAKE34 Scattering system with 400 mm source is also being considered For detector We can make array or single coner-cube detector. Possible UNIST Contribution 3 12/12/2014Moses Chung | UNIST for AWAKE35 We have developed a parallelized particle-in-cell (PIC) code using Graphics Processing Units (GPUs) which achieved the calculation performance of around 1 ns per particle for 100 million particles in hundreds of thousand cells with a single GPU. In this case, the calculation time of 100 million particles for 1 million time steps is within 1.5~2 days for a single GPU machine which costs less than 6k USD. Therefore, parameter optimization becomes easier by running lots of test cases in a fast and economic computer system rather than a expensive super computer or clusters. With Prof. H. J. Lee + Lots of Experience in low temp discharge simulation Laser ionization of gas ? Nonlinear Blowout wakefields r n e = 3 x cm -3 I = 3.46 x (W/cm 2 ) a 0 = 4.0 waist = 4 ( m) Laser duration = 30 (fs), = 800 (nm) Trajectory of the trapped electrons (0.78 pC / m) Betatron Oscillation of Electron With Prof. H. J. Lee 12/12/2014Moses Chung | UNIST for AWAKE36 Currently Available Resources Full support for two UNIST graduate students. Startup (0.1M USD): Could be used for constructing corrugated structure development and test. Korean industry made world- first prototype in ~ 0.2M USD with all controllers. Once formal MOU is formed, I will apply for additional funding Injector Test Facility (ITF) beam time at Pohang Accelerator Laboratory (PAL) Travel money Supercomputing center CPU time 12/12/2014Moses Chung | UNIST for AWAKE37