摘要:

It has been reported that plasma confinement in the cold region of a Uramoto‐type sheet plasma ion source is very important for negative hydrogen ion production [Rev. Sci. Instrum.66, 1035 (1995)]. In the present experiments, the stainless chamber was biased as low as 100 V relative to the anode potential in a 150 V–15 A discharge. The negative hydrogen ion current density (5 mA/cm2) was found to be larger than the positive hydrogen ion current density under the same experimental conditions. These experimental results suggest that the negative hydrogen ions are formed directly from atomic hydrogen. ©1995 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146031

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

In this paper we describe the design of a simple Bridgman opposed anvil cell to measure the thermoelectric power of solids as a function of pressure up to 100 kbar. The anvils are made of EN‐24 alloy steel hardened to RC55. ©1995 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146032

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The key to obtaining good spatial resolution for neutral‐beam‐based optical diagnostics in tokamak plasmas is that the narrow optical sightline must cross the wide neutral beam path at a point where the sightline is tangent to the toroidal direction. For a single one‐dimensional pinhole camera arrangement, this condition can be met at two points of interest in the plasma, such as the magnetic axis and the plasma edge. The camera location required to provide optimized spatial resolution is calculated. We find that the camera must be placed closer to the plasma edge as the neutral beam is aimed more tangentially. ©1995 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146033

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A new type of pulse compression circuit is proposed to generate low impedance pulse power. By using the circuit, high efficiency, low load of switching device, and reduction of reflected pulse are expected and it is suitable to produce a low impedance pulse. Performance of the system is evaluated by a computer simulation and compared with a conventional circuit using a pulse forming line. Energy transfer efficiency of 94% is obtained which is 15% higher than the conventional one. TheV&tgr; value of the switching device is reduced to 56% of that for a conventional circuit. ©1995 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146034

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A Nd:YAG laser device for perforating materials was developed. The device generates a modified temporal pulse structure of both free‐running andQ‐switched laser irradiation. This modified structure enhances drilling efficiency by a factor of 2 compared to free‐running irradiation and is achieved by mechanical blow‐off of preheated material. Such a device is well suited for compact portable field applications. ©1995 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1146035

出版商:AIP    

年代:1995

数据来源: AIP