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Questions related from Donggyu Jang
Hello. I've read some article that the inverse bremsstrahlung is the process that a free electron absorbs a photon while it collides with an ion, so it is 3-body process. But I don't know how it...
30 May 2017 8,821 2 View
Hello. This notation really makes me crazy. It is even very hard for me to find out which material is good to explain this notation. According to NIST Atomic Spectra Database Levels Form...
08 January 2017 1,395 4 View
Hello. I'm looking for a way to get a supersonic gas jet with a small nozzle for the laser-plasma experiment such as laser-plasma acceleration. I think the nozzle diameter should be less than 500...
05 December 2016 5,784 1 View
Hello. I would like to find out a dispersion relation of a hydrogen gas at 0 Celsius. Room temperature is even okay. I'd tried to find this on the internet, however, it appeared that many papers...
19 October 2016 8,069 4 View
Hello. For example, In NIST ASD, it is said that configuration of 1st excited state of neutral Argon is 3s23p5[2P3/2]4s and Term symbol is 2[3/2]2. It looks there are two term symbols here. One is...
11 July 2016 6,028 6 View
Hello. I'm now trying to make Argon plasma discharge simulation. In order to do this, I need to know cross section of Argon for various reaction (ionization, excitaiton and etc) with incident...
08 July 2016 9,311 5 View
Hello. I'm reading plasma-related paper telling that ion neutralization at the surface is due to Auger neutralization. What is the Auger neutralization? And most of the paper only mentions...
24 June 2016 4,710 3 View
Hello. I'm studying ICP (Inductively Coupled Plasma) and reading famous paper, "Plasma Sources Sci. Techno.l. 1 (1992) 179-186, "A simple analysis of an inductive RF discharge", R B Piejak, V A...
25 April 2016 8,858 6 View
Hello. I'd done some research activity with display panel manufacturer and was involved with laser-based silicon crystallization in which amorphous silicon is converted to poly-silicon...
23 April 2016 1,893 2 View
Hello. Our lab has significant portion of job associated with the single-shot HV (High Voltage) gas discharge. Peak current is several hundreds amperes and rising time to peak is about ~ 100...
26 November 2015 8,388 2 View
Hello. Please see the attached images which shows our capacitively gas discharge circuit. HV box has single output of 30 kV. Before thyratron (fast electrical switch) is on, everything looks clear...
20 July 2015 285 5 View
Hello. Let's say we have narrow sapphire tube (~300 um width and few cm length) which is filled with gas and discharged capacitively with high voltage of ~ 30 kV. With sub atm pressure, we can get...
08 July 2015 4,133 4 View
Hello. I have a plan to make new version of Faraday cage for gas discharge circuit. Unlikely to current cage in which radiation sources such as Thyratron and capacitor are just proximate to some...
01 July 2015 7,377 5 View
Hello. I'm now trying to calculate the inductance of a single wire as a ground wire. We're in High voltage lab thus inductance of ground wire seems really important to stabilize the system since I...
24 June 2015 1,708 27 View
Hello. Currently in our gas discharge plasma lab, the discharge unit is connected to discharge system via single wires, the wires to run and return current. It has been clear that rising time of...
15 June 2015 1,515 5 View
Hello. I'm thinking about making system to generate several Tesla magnetic field. We will have typical coil-type ICP (Inductively Coupled Plasma) and external B field is imposed on plasma. As...
27 May 2015 2,872 3 View
Hello. I've read paper concerning ICP (Inductive Coupled Plasma) in which argon gas is flowing through 1 atm environment (Just normal air). The paper assumed argon gas pressure is 1 atm. Is it...
15 May 2015 3,582 2 View
Hello. Let's say plasma is discharged inside the vacuum chamber which is completely shielded and properly grounded to earth. Then radiation comes out from plasma. Let's say RF frequency radiation...
29 April 2015 2,681 6 View
Hello. Maybe this is essentially the same question to previous question what I made, but I would like to clarify this. My questions are like this: What is the role of BNC terminator? (The...
17 April 2015 6,173 4 View
Hello. The mechanism of the gas discharge is quite well-known when the gas is filled between two plane electrodes. In this case electron emission from cathode have significant role to get into...
14 April 2015 2,231 7 View
Hello. I'm now considering to generate plasma which electron density ranges from 10^13 to 10^14 cm^(-3). The choice of this density range is from the fact that this plasma would be actually test...
13 April 2015 1,848 8 View
I know this should be complicated issue thus seems no clear answers. I just want to get some basic rule for grounding. Our lab is to discharge sub-atm pressure hydrogen gas with several tens of kV...
02 April 2015 1,643 7 View
Hello. We're dealing with the HV (High Voltage) gas discharge thus electrical grounding is crucial issue for devices personal safety. I've done many effort to make good grounding but still have...
02 April 2015 2,810 3 View
Hello. We have Ti:sapphire ultrafast laser. In oscillator, the bandwidth of the Kerr-lensed mode-locked (phase-locked) laser is exceeding 60 or 70 nm. After passing through two amplification...
24 February 2015 1,579 3 View
Hello. There is an instument with HighZ load and this is connected via 50 Ohm BNC cable to Oscilloscope(OSC) with several impedance selections (HighZ, 75 and 50 Ohm). People say I can choose 50...
21 February 2015 8,723 10 View
Hello. For typical spherical lens, calculation of the focused intensity for the laser is simple: numerical number gives diffraction limited focused radius of the laser thus everything is...
16 February 2015 1,191 5 View
Hello. The standard way of expressing collisional freq is n*sigma*v where n, sigma and v represents target species density, collisional scattering cross section and mean incident particle...
07 October 2014 3,487 2 View
Hello. I originally try to obtain the hydrogen scattering cross section with incident proton. However, over the range of incident particle energy what I interested in (about 2 eV) there are not...
02 September 2014 702 1 View
Hello. I'm now calculating charge of the e-bunch generated from the photocathode which is hit by the laser pulse. The following is my condition. 1. Laser energy: 600 mJ. 2. Laser diameter: 7...
31 July 2014 314 5 View
I'm studying discharge mechanism of the gas when high voltage applies. Longitudinally two ring-type electrodes are present while gas is transversely surrounded by a dielectric material. I've...
20 June 2014 8,845 3 View
I'm looking for the way of measuring emittance of the electron beam. The beam is generated by the laser incident on the copper and it is accelerated up to 20 keV or little higher in D.C...
19 June 2014 9,177 5 View
I'm working in the plasma physics and trying to calculate the thermal conduction time or speed. The plasma treated has cylindrical symmetry surrounded by the dielectric material. Right now I need...
03 June 2014 3,407 10 View
The usual expression of the electrical conductivity is e^2*n_e/(m_e*v_ei) where e is the electrical charge, n_e the electron density, m_e electron mass, v_ei is collision frequency between...
30 May 2014 6,824 3 View
