M1 Colloquium High-pressure Generation by Gekko-Ⅻ/HIPER Laser towards the metallization of the diamond. SHIMIZU-group M1 Yasuhiro Asakura CONTENTS Introduction ・Our group Motivation ・Carbon Phase Diagram ・Laser Compression Compression of Diamond Experiment Result & Discussion Summary Future Work INTRODUCTION Shimizu-Group Multiple Extreme Conditions High Pressure (over 200 GPa) Low Temperature (～15 mK) Strong Magnetic Field (～14 T) (1GPa≒1万気圧) Our group investigate properties of various materials. ex) metallic , superconductivity ・・・ ・high-pressure generation device Diamond Anvil Cell (DAC) INTRODUCTION Carbon BC8:body centered cubic with eight atoms per primitive cell Diamond is the hardest material The property of compressed Diamond SC4:simple cubic Carbon Phase Diagram is very interesting. Aim to metalize for Diamond If this ultrahigh-pressure phase could be quenched to an ambient pressure, the metal with the characteristic of a super lightweight and super-hardness becomes feasible. Pressure (GPa) (1.2~1.3TPAa ,4000~7000K) 104 103 2 10 DAC limit Diamond Liquid 101 Graphite but DAC compression limit (~ 350 GPa) Simple cubic? BC8? 0 2000 6000 10000 Temperature (K) M.P.Grumbach and R.M.Martin,Phys.Rev.B54 15730(1996) Laser Compression INTRODUCTION Strong Shock Compression with Intense Laser The laser compression is generated in a very short time (about only a few nanoseconds), however this method easily can generate over 10TPa. High-intensity(over1kJ) Delay The GEKKO-HIPER facility has 12 One beams which direction irradiation The time :2.5 ns irradiates planar target from one direction. advantage of its irradiation configuration is excellent spatial uniformity of the drive laser , and it is possible to create shaped laser pulses with time delay between the individual beams . Gekko Ⅻ/HIPER system(激光Ⅻ号ハイパー） (High Intensity Physics Experimental Research) The Japan Society of High Pressure Science and Technology Vol.17,No.4(2007) INTRODUCTION Laser Compression Strong Shock Compression with Intense Laser Shock-Wave reaction from Laser ablation shock-wave generation Compression Pressure depend on Wavelength Intensity Pa(GPa)＝ 860 (Ⅰ/λ)2/3 The Japan Society of High Pressure Science and Technology Vol.17,No.4(2007) INTRODUCTION Entropy and Multiple Shock Compression problem This method can reach the pressure of over 1TPa. single shock compression ideal Increase possessively Multiple Shock Compression Laser intense intensity ・Need to keep low entropy Pressure (GPa) But in the dynamic pressing like this, all the same time, temperature rapidly increase. 104 103 Hugoniot Curve Simple cubic? BC8? DAC limit 2 10 Diamond Liquid 101 Graphite 0 2000 time this experiment Single and Double Shock Compression 6000 10000 Temperature (K) INTRODUCTION The Rankine-Hugoniot jump conditions 0 u s u p 0 1 u s u p1 P1 P0 0 u s u p 0 u p1 u p 0 E1 E0 1 P0 P1 1 1 2 0 1 E :internal energy ρ :density us :shock velocity up :particle velocity Rev.Mod.Phys.49,523(1977) ・Calculate the pressure(p1) by us and up1 ρ0：density (about 3.52 g/cm3 for Diamond) 0:before 1:after EXPERIMENT Target Diamond(Ⅰb＆NPD) Ⅰb 単結晶 ・2mm square ・about 50μm thick(35~60μm) Pt Diamond Laser Ⅰ:2 x 1013W/cm2 λ：0.35 μm NPD 多結晶 VISAR YAG prove beam (1～9 beams) Au 5 mm Ti Ti&Pt coat about 0.1 mm SSOP EXPERIMENT Pressure experimental method Hugoniot’s formula P1 P0 0 us u p 0 u p1 u p 0 Estimate the pressure(p1) by us and up1 Time position Streak + CCD target n1 Phase change⇒Fringe pattern shift Target come close Doppler shift n2 velocity Velocity Interferometer System for Any Reflector (VISAR) EXPERIMENT Temperature experimental method Self Emission Measurement 1000 approximation 8 6 black-body radiation E ( , T ) 2hc2 5 1 e hc kT 1 Intensity[a.u.] 4 2 100 8 6 4 2 10 12000K 10000K 8000K 6000K 8 6 4 200 Spectrum form ⇒ Temperature Spectrum Streaked Optical Pyrometer (SSOP) 300 400 500 600 Wavelength[nm] 700 800 RESULT & DISCUSSION Analysis 2 Single Compression BC8 Pressure[GPa] 1000 6 5 4 demonstration 3 2 Diamond Liquid 100 On Hugoniot Curve Carbon phase Hugoniot Curve Experiment 6 5 4 3 2 0 5 10 15 20x10 3 Temperature[K] Double Compression couldn’t determine the pressure, because appear the Doppler shift in VISAR. ・Only determined the temperature Expect from reflection ・・・・ RESULT & DISCUSSION Discussion In the past works, bright reflection was observed in VISAR by metal transition. Why didn’t observe the bright reflection? ・Didn’t reach the Phase of BC8. ・Could reach the Phase of BC8, but couldn’t observe the bright reflection because of the trouble of equipment. ・ Could acquire the enough pressure and temperature, however the theory curve was in fault. In any case, it is necessary to raise the precision of the measurement. (VISAR) . Summary Experiment under ultrahigh-pressure (never reach for DAC) by Laser Compression. Gekko Ⅻ/HIPER system Replicate ON Hugoniot of Single Compression (Single compression can’t reach metalized Diamond.) Can’t determine the pressure of Double Compression 4 →Keep low temperature 10 BC8? 3 ＆ 10 DAC limit 2 Reach ultrahigh-pressure ? 10 Liquid 1 (over 800GPa at 5800 K) 10 Pressure (GPa) Graphite 0 2000 6000 10000 Temperature (K) Future Work ・ Raise the precision of the measurement Enable to determine the pressure of Double Compression Metalize and more （ Multiple Compression・・・SC4?） ・Analyze the structure by the X-ray diffraction collaborative study Laser-group (Institute of Laser Engineering, Osaka University) Kondo-group (graduated school of science) Thank you for your attention.
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