Laboratory
manual
Plasmaline 415
plasma
chamber
For questions e-mail Poulomi Sanyal: poulomisanyal@yahoo.co.in
Components AND ACCESSORIES
The various components of the plasma chamber are shown and labeled below
The set up
Inside of the chamber
vacuum pump
chamber
Rear-side view of chamber
plasma gas inlet
compressed gas
(N2) actuated
auxiliary valve
venting gas inlet
Figure 1 Components
Compressed gas
compressed N2 to
actuate auxiliary valve
OPERATION
Turning on the vacuum pump and chamber power supply
The first step in starting the plasma chamber is turning on the vacuum pump by plugging
it in to the electric supply.
The second step is to turn the knob on top of the compressed Nitrogen cylinder o turn on
the Nitrogen supply and the third step is to switch on the AC supply of the plasma
chamber by pressing the big red switch shown below:
Figure 2 On/Off switches
Choosing mode of operation
There are two modes of operation for the plasma chamber, namely manual and auto and
the mode we wish to operate in can be selected by turning the knob shown below.
RF Power meter
RF power button
knob to control
chamber pressure
control by controlling
gas flow
Heater switch
RF power control
Figure 3 Parameter Control Switches
The chamber must be kept under vacuum when it is turned off and the knob should then
be in the manual position. So while turning it back on, the knob should be left in the
manual position and the orange start/stop button shown in Figure 2 must be pressed to let
the chamber start venting. When venting is complete the chamber will be released from
vacuum and the door can then be opened.
Turning on the gas and plasma
The next step is to place the samples inside the chamber and close the door tightly. The
mode of operation should be changed from manual to automatic.
After that the auxiliary pump must be manually turned on by pressing the orange
start/stop button shown in Figure 2.
How the device will operate once you press the start/stop switch, and also how you will
proceed to control your chamber parameters such as temperature, pressure, flow-rate and
RF-power will depend on the mode of operation you have selected
Here is what will happen for each of the two modes.
 Auto mode
For the automatic mode, which is the preferable mode of operation, activating the
start button immediately initiates the operation of the N2 activated auxiliary pump.
Thus the chamber pressure drops rapidly. Once the chamber pressure drops
considerably the gas input valve opens and gas entry begins. This causes a sudden
initial rise of chamber pressure after which the pressure starts dropping again and
when the pressure becomes steady the RF power switches on automatically. Once the
RF power (plasma) is on you must activate your sample for the desired amount of
time (depending on your protocol) and keep track of time manually using a stopwatch
(since the timer on the plasma chamber doesn’t work). Once your activation is
complete you must press the orange button again to stop the plasma, then wait for the
chamber to vent and when the chamber has vented and the door can be opened again,
open the door and remove your samples.
 Manual mode
In the manual mode the difference is that the plasma does not turn on automatically.
So once the chamber has reached an appropriate pressure (depending on your
protocol) you must manually turn on the plasma by turning the same knob that you
use to select the mode of operation.
Controlling the plasma characteristics
During operation you can regulate the following parameters of your plasma using knobs
provided on the chamber:
Pressure: The gas pressure (currently the gas is just air so we essentially get an air
plasma) inside the chamber can be regulated at any point during the experiment using
the knob shown in Figure 3.
RF Power: Once the plasma is on, the reflected RF power can be seen by pressing the
black RF power button next to the power meter shown in Figure 3. You can adjust the
RF power to amount you require (depending on your protocol) by turning a knob that
is on the right hand side of the chamber when you’re facing the chamber door.
Time: As mentioned earlier the time has to be controlled manually using a stop watch
because the chamber timer does not work.
Heating: If you would like to have extra heat in the chamber then you can turn on the
heater using the knob shown in Figure 3.
Turning off the chamber
Once the plasma activation is complete and the samples are removed, the chamber door
should be closed again and the manual mode should be selected then the orange start stop
button should be pressed. Once that is done the chamber will start falling again and after
a while you will no longer be able to open the door. When that happens the red “AC ON”
button shown in Figure 2 should be pressed to switch off the chamber while it’s still
under vacuum. Then you must unplug the vacuum pump and close the nitrogen bottle
before leaving.
CLEANING, MAINTENANCE and Safety
Cleaning
The recommended solvent for cleaning both the inside and the outside of the plasma
chamber is isopropyl alcohol or isopropanol.
It is not advisable to clean the inside of the chamber with water. Even solvents like
ethanol and methanol are not good options.
Also, the plasma may be made to run for a few minutes without any samples for autocleansing of the chamber. Running the plasma for a while will burn away any oil or fat
that may have rubbed on from people’s fingers.
Maintenance and safety
As soon as the plasma chamber is switched on, a burst of oil vapor issues from the
vacuum pump exhaust. This vapor is not good to inhale and should be exhausted through
a proper exhaust system. It is not advisable to exhaust these vapors through a fume hood
because they are flammable and may cause a fire if oxidizing agents are used inside the
fume hood later.
Metal pieces should not be placed inside the plasma chamber while it is in operation in
such a way that the plasma circuit gets shorted out.