Risks of explosion mixing O2 and H2 in Ar magnetron plasma?

In summary, the conversation discusses the potential risks of adding both O2 and H2 in a magnetron sputtering discharge ignited in Ar at a pressure of 3*10-2 mbar. The discharge is driven by a RF generator (13.56 MHz, 60 - 120W) and the target is W. The contributors suggest calculating the reaction enthalpy to determine the potential for explosion, as well as considering the potential and flow rate of the gases to prevent recombination and avoid explosions.
  • #1
atomica68
2
0
I am interested in adding simultaneously O2 and H2 in a magnetron sputtering discharge ignited in Ar at a pressure of 3*10-2 mbar. The discharge is driven by a RF generator (13.56 MHz, 60 - 120W). The target is W. Can anyone told me if I can expect at any explsion to apear due to simultanoously presence of O2 and H2 in the discharge?
Thank you in advance for responses.
 
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  • #2
I think you can figure this out yourself. How much energy would be released if all of the H2 and O2 in your experiment reacted? How does this compare with the amount of energy going into the experiment from the RF generator?
 
  • #3
Exactly my thought - simple calculation of reaction enthalpy given number of moles of the substance should tell you if there is any risk involved. Especially taking into account you work in vacuum, so the chamber must be quite sturdy.
 
  • #4
What is the potential applied across the tungsten and the plasma? Also, what is the flow rate of the two gasses? I work with ICPMS and have experience dealing with argon plasma ionization, but ours is at 1500W (~10,000 K) and potentials of 5 - 10V. The hydrogen and oxygen should ionize instantly going into the plasma. They will want to recombine afterwards as one would expect, but if the potential is high enough, you may accelerate the ions fast enough to hit the target before then. The concept is the same with ICPMS where the ions are accelerated and focused with lenses to prevent recombination. Typically, when tuning a plasma to produce less recombination, a lower flow rate is used. Explosion is not typically seen unless too much gas is being pumped in.
 

1. What is the main risk of mixing O2 and H2 in Ar magnetron plasma?

The main risk of mixing O2 and H2 in Ar magnetron plasma is the potential for explosion due to the highly reactive nature of these gases. When exposed to high energy plasma, O2 and H2 can react and rapidly release large amounts of energy, leading to an explosion.

2. How does the concentration of O2 and H2 affect the risk of explosion in Ar magnetron plasma?

The concentration of O2 and H2 is a crucial factor in determining the risk of explosion in Ar magnetron plasma. Higher concentrations of these gases increase the likelihood of a reaction and subsequent explosion, while lower concentrations may not pose as much of a risk.

3. Are there any safety measures that can be taken to minimize the risk of explosion when using O2 and H2 in Ar magnetron plasma?

Yes, there are several safety measures that can be taken to minimize the risk of explosion when using O2 and H2 in Ar magnetron plasma. These include proper ventilation and gas monitoring, using appropriate protective equipment, and following established protocols for handling and mixing these gases.

4. Can the risk of explosion be completely eliminated when mixing O2 and H2 in Ar magnetron plasma?

While there are safety measures that can greatly reduce the risk of explosion, it is nearly impossible to completely eliminate the risk when mixing O2 and H2 in Ar magnetron plasma. These gases are highly reactive and any small mistake or equipment malfunction can still lead to an explosion.

5. Are there any alternative gases that can be used in place of O2 and H2 in Ar magnetron plasma to avoid the risk of explosion?

Yes, there are alternative gases that can be used in place of O2 and H2 in Ar magnetron plasma to avoid the risk of explosion. These include less reactive gases such as nitrogen or helium. However, these gases may not have the same effects on the plasma and may require adjustments to the process.

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