Development of quartz crystal microbalance deposition diagnostic system for HL-2A divertor

doi:10.16568/j.0254-6086.201701003

Abstract

Abstract:

In order to measure the deposition in the remote area behind the divertor of a tokamak due to plasma wall interactions (PWI) and get a better understanding of PWI process in this remote area in real time, the first quartz crystal microbalance (QCM) deposition diagnostic system for the HL-2A divertor was developed. After the preliminary test, it was found that the average sampling rate is about 13~14s^-1 and its frequency resolution is 0.01Hz. The resonant frequency shift of the crystal is proportional to the mass change deposited in the surface of the crystal, which coincides with conclusion from the famous Sauerbrey equation. The average deposition rate is about 2.0ng•s^-1, which means it is capable to measure nanogram quality. These results show that this QCM deposition system is reliable and effective.

Key words: Quartz crystal microbalance, Deposition, Plasma wall interaction, HL-2A divertor

摘要：

为了检测HL-2A偏滤器靶板的背后沉积层的沉积情况和深入了解其等离子体与第一壁的相互作用过程，国内首次研制了用于托卡马克装置的偏滤器沉积测量系统，其中包括石英晶体、测量探头、频率测量以及控制系统等。经过初步检测，该沉积系统平均采样速率为13~14s^-1；测量的石英晶体共振频率分辨率为0.01Hz；石英晶体共振频率的变化正比于沉积在石英晶体表面的质量的变化，这与Sauerbrey方程的线性关系吻合；实验室检测过程中该沉积系统的平均沉积率约为2.0ng•s^-1，显示该沉积系统具有纳克级质量检测能力，表明了该偏滤器沉积系统的测量性能和有效性。

关键词: 石英晶体微天平, 沉积, 等离子体与壁的相互作用(PWI), HL-2A偏滤器

CLC Number:

TL62+1

WU Ting, CAI Lai-zhong, ZENG Xiao-xiao. Development of quartz crystal microbalance deposition diagnostic system for HL-2A divertor[J]. NUCLEAR FUSION AND PLASMA PHYSICS, 2017, 37(1): 14-18.

吴婷，才来中，曾晓晓. HL-2A偏滤器沉积测量系统的研制[J]. 核聚变与等离子体物理, 2017, 37(1): 14-18.

References

[1] Bourgion, Ross G G, Savoie S, et al. Use of a quartz microbalance for plasma-wall interaction studies[J]. Nucl. Mater., 1997, 241-243: 765-770.

[2] 沈洪, 汪宪明, 沈力. 石英晶体微天平分析技术进展[J]. 四川化工与腐蚀控制, 2002, 5(4): 23-26.

[3] 聂利华, 姚守拙. 压电液相化学分析[J]. 分析化学, 1996: 234-241.

[4] Rohde V, Maier H, Krieger K, et al. Carbon layers in the divertor of ASDEX Upgrade[J]. Nucl. Mater., 2001, 290-293: 317-320.

[5] Rohde V, Mayer M, the ASDEX Upgrade Team. On the formation of a-C: D layers and parasitic plasmas underneath the roof baffle of the ASDEXUpgrade divertor[J]. Nucl. Mater., 2003, 313-316: 337-341.

[6] Von Seggern J, Wienhold P, Hirai T, et al. Long term behaviour of material erosion and depositionon the vessel wall and remote areas of TEXTOR[J]. Nucl. Mater., 2003, 313-316: 439-443.

[7] Esser G H, Neill G, Coad P, et al. Quartz microbalance: a time resolved diagnostic to measure material deposition in JET[J]. Fusion Engineering and Design, 2003, 66-68: 855-860.

[8] Coad J P, Esser G H, Likonen J, et al. Diagnostics for studying deposition and erosion processes in JET[J]. Fusion Engineering and Design, 2005, 74: 745-749.

[9] Esser G H, Philipps V, Freisinger M, et al. Carbon deposition in the inner JET divertor measured by means of quartz microbalance[J]. Physica Scripta, 2004, T111: 129-132.

[10] Kreter A, Brezinsek S, Coad J P, et al. Dynamics of erosion and deposition in tokamaks[J]. Nucl. Mater., 2009, 390-391: 38-43.

[11] Esser G H, Kreter A, Philipps V, et al. Erosion and deposition behaviour of a-C: H layers in the private flux regionof the JET MKII-HD divertor[J]. Nucl. Mater., 2009, 390-391: 148-151.

[12] Esser G H, Philipps V, Freisinger M, et al. Effect of plasma configuration on carbon migrationmeasured in the inner divertor of JET using quartz microbalance[J]. Nucl. Mater., 2005, 337-339: 84-88.

[13] Kreter A, Esser G H, Brezinsek S, et al. Nonlinear Impact of Edge Localized Modes on Carbon Erosion in the divertor of the JET tokamak[J]. Phys. Rev. Lett., 2009, 102: 045007.

[14] Krieger K, Brezinsek S, Jachmich S, et al. Be wall sources and migration in L-mode discharges after Be evaporation in the JET tokamak[J]. Nucl. Mater., 2009, 390-391: 110-114.

[15] Skinner H C, Kugel H, Roquemore A H, et al. Time resolved deposition measurements in NSTX[J]. Nucl. Mater., 2005, 337-339: 129-133.

[16] Skinner H C, Kugel H W, Roquemore A H, et al. Pulse-by-pulse measurements of dynamic retentionand deposition in NSTX[J]. Nucl. Mater., 2007, 363-365: 247-251.

[17] Skinner H C, Kugel H W, Roquemore A H, et al. Mass changes in NSTX surface layers with Li conditioning as measured by quartz microbalances[J]. Nucl. Mater., 2009, 390-391: 1005-1008.

[18] Skinner H C, Rais B, Roquemore A H, et al. First real-time detection of surface dust in a tokamak[J]. Review of Scientific Instruments, 2010, 81: 102.

[19] Ochoukov R, Whyte D, Lipschultz B, et al. Study and optimization of boronization in Alcator C-Mod using the surface science station[J]. Fusion Engineering and Design, 2012, 87: 1700-1707.

[20] Sauerbrey G Z. Use of quartz crystal units for weighing thin films and microweighing[J]. Magzine for Physics , 1959, 155(2): 206-222.

[21] 林珩, 林燕美, 郭艺容, 等. 影响石英晶体微天平频率变化因素的分析[J]. 漳州师范学院学报(自然科学版), 2008, 4: 85-89.

[22] 吕广宏, 罗广南, 李建刚. 磁约束核聚变托卡马克等离子体与壁相互作用研究进展[J]. 中国材料进展, 2010, 29(7): 42-48.

[23] 朱士尧. 核聚变原理[M]. 合肥: 中国科学技术大学出版社, 1992. 280-320.

[24] Federici G, Skinner H C, Brooks J N, et al. Plasma material interactions in current tokamak sand their implications for next step fusion reactors[J]. Nucl. Fusion, 2001, 41: 1967-2137.