How Does Air Pressure Affect the Range of Alpha-Particles?

[wulmazboy]

Alpha-particles (helium nuclei) from a particular radioactive source have range of about 6 or 7 cm in air. This is because the kinetic energy of the alpha-particles is continually being transferred to air molecules due to collisions between the alpha-particles and the air molecules.

Design a laboratory experiment to investigate how the range of alpha-particles in air is affected by the air pressure. In your account it is expected that you will

(a) draw a diagram showing how the apparatus would be used in your investigation,
(b) explain clearly the procedure to be followed,
(c) name the alpha-particle detector which you would use,
(d) state any safety precautions which may need to be taken when performing the experiment.

-----------------------------------------------------------------------------------------
Perform experiment in closed container

Use vacuum pump to reduce pressure
(Do not allow 'climb mountains', 'use a helicopter' etc..
A laboratory method must be employed)

('pressure gauge' shown) to measure air pressure

Geiger-Müller tube stated as detector

Diagram of apparatus
Source/detector/rule/pressure gauge/closed container

Any mention of compensating for background radiation
No details required.

Procedure to be followed
Must be workable (e.g. move GM tube to point = background;
reduce air pressure and move GM tube to position which gives
the same count rate as before and measure distance)


THE INFORMATION ABOVE THE DOTTED LINES WAS THE QUESTION GIVEN , THE INFORMATION BELOW IS WHAT I HAVE OBTAINED FROM MY UNDERSTANDING BUT STILL IM UNSURE OF MY CHOICES, ANY HELP WILL BE DEEPLY APPRECIATED


<< extraneous comment deleted by Moderators >>

 

[berkeman]

Alpha-particles (helium nuclei) from a particular radioactive source have range of about 6 or 7 cm in air. This is because the kinetic energy of the alpha-particles is continually being transferred to air molecules due to collisions between the alpha-particles and the air molecules.

Design a laboratory experiment to investigate how the range of alpha-particles in air is affected by the air pressure. In your account it is expected that you will

(a) draw a diagram showing how the apparatus would be used in your investigation,
(b) explain clearly the procedure to be followed,
(c) name the alpha-particle detector which you would use,
(d) state any safety precautions which may need to be taken when performing the experiment.

-----------------------------------------------------------------------------------------
Perform experiment in closed container

Use vacuum pump to reduce pressure
(Do not allow 'climb mountains', 'use a helicopter' etc..
A laboratory method must be employed)

('pressure gauge' shown) to measure air pressure

Geiger-Müller tube stated as detector

Diagram of apparatus
Source/detector/rule/pressure gauge/closed container

Any mention of compensating for background radiation
No details required.

Procedure to be followed
Must be workable (e.g. move GM tube to point = background;
reduce air pressure and move GM tube to position which gives
the same count rate as before and measure distance)


THE INFORMATION ABOVE THE DOTTED LINES WAS THE QUESTION GIVEN , THE INFORMATION BELOW IS WHAT I HAVE OBTAINED FROM MY UNDERSTANDING BUT STILL IM UNSURE OF MY CHOICES, ANY HELP WILL BE DEEPLY APPRECIATED


<< extraneous comment deleted by Moderators >>

What are your thoughts so far? We will not design this experiment for you, but we should be able to answer specific questions once you post your thoughts on how to set up the experiment.

I'm especially interested in how you plan to move things inside the vacuum chamber...

 

[stonecoldgen]

cant you just use a syringe?

 

[berkeman]

cant you just use a syringe?

Use a syringe for what?

 

[rwisz]

I would recommend the following experiment to investigate how the range of alpha-particles in air is affected by air pressure:

(a) The experiment would involve a closed container with a vacuum pump attached to reduce air pressure. The container would also have a pressure gauge attached to measure the air pressure inside. A Geiger-Müller (GM) tube would be placed inside the container to detect the alpha-particles. A ruler would also be placed inside the container to measure the distance traveled by the alpha-particles. A diagram of the apparatus is shown below:

(Source/detector/ruler/pressure gauge/closed container)

(b) The procedure would be as follows:
1. Set up the closed container with the vacuum pump and pressure gauge attached.
2. Place the GM tube and ruler inside the container.
3. Record the distance between the source and the GM tube.
4. Turn on the vacuum pump to reduce the air pressure inside the container.
5. Record the new air pressure on the pressure gauge.
6. Move the GM tube to a position where it receives the same count rate as before (this would compensate for background radiation).
7. Measure the new distance between the source and the GM tube.
8. Repeat steps 4-7 for different air pressure levels.

(c) The alpha-particle detector used in this experiment would be a Geiger-Müller tube. This type of detector is commonly used to detect ionizing radiation, including alpha-particles.

(d) Safety precautions that should be taken when performing this experiment include wearing appropriate protective gear, such as gloves and goggles, when handling the source and working with the vacuum pump. Care should also be taken when handling the closed container to avoid any accidental breakage or damage. It is also important to follow proper handling and disposal procedures for the radioactive source.