The Martian.... A question
- Thread starter mjpwooo
- Start date
Good question...I cheated and looked it up:
A BIG BOX OF PLUTONIUM
Mark's solution, as he puts if, is to use a big box of plutonium. In this case, that big box is known as a radioisotope thermoelectric generator or RTG. The RTG generates electricity from the heat of a decaying radioactive substance, in this case, plutonium-238. This element is incredibly unstable. The nucleus breaks apart and emits radiation in the form of alpha particles or high-speed helium particles. As the alpha particles leave the plutonium nucleus, they slam into other nearby atoms and lose kinetic energy This lost energy is converted to heat. So much kinetic energy is lost that the plutonium gets red all by itself. As you guessed, Mark needs to be very careful. Any material that can fry an egg with radiation is kind of dangerous!
The Mars Science Laboratory’s radioisotope power system was assembled by putting nuclear heat sources within graphite impact shells into high-strength carbon-carbon modules at Idaho National Laboratory.
The RTG is not a nuclear reactor; it can not be controlled and its radiation output can not be increased or decreased. Everything happens naturally at the atomic level. Fortunately for Mark, it does not take much shielding to stop alpha-particles. Because of their large atomic mass, alpha particles are easily stopped by matter and can only travel a few centimeters in air. They can be absorbed by something as thin as tissue paper, or the outer layers of human skin -- which is approximately 40 micrometers thick, the equivalent of a few cells deep. Mark's RTG contains about 2.6 kilograms of plutonium and generates 1500 Watts of heat. Thermocouples positioned around the device convert 100 Watts of that heat into electricity.
This does not mean Mark should stop worrying. Pu-238 is still pretty dangerous. There is a reason why NASA does not want to put its astronauts next to glowing balls of death! While alpha particles cannot penetrate skin, ingesting or inhaling plutonium can travel deep into the body to irradiate internal organs. The element is accumulated in the liver and skeleton and becomes concentrated in those organs.
The unstable uranium-238 nucleus decays into a thorium nucleus and an alpha particle. The high-speed alpha particle loses kinetic energy and is converted to heat. Image credit: © Copyright CSIRO Australia 2004, via http://outreach.atnf.csiro.au/.
Fortunately for Mark, each plutonium pellet is sealed and insulated in graphite to prevent radiation leakage. Even if the seal is ruptured, Mark should be safe as long as he takes precautions to not breathe or ingest any radioactive particles
A BIG BOX OF PLUTONIUM
Mark's solution, as he puts if, is to use a big box of plutonium. In this case, that big box is known as a radioisotope thermoelectric generator or RTG. The RTG generates electricity from the heat of a decaying radioactive substance, in this case, plutonium-238. This element is incredibly unstable. The nucleus breaks apart and emits radiation in the form of alpha particles or high-speed helium particles. As the alpha particles leave the plutonium nucleus, they slam into other nearby atoms and lose kinetic energy This lost energy is converted to heat. So much kinetic energy is lost that the plutonium gets red all by itself. As you guessed, Mark needs to be very careful. Any material that can fry an egg with radiation is kind of dangerous!
The Mars Science Laboratory’s radioisotope power system was assembled by putting nuclear heat sources within graphite impact shells into high-strength carbon-carbon modules at Idaho National Laboratory.
The RTG is not a nuclear reactor; it can not be controlled and its radiation output can not be increased or decreased. Everything happens naturally at the atomic level. Fortunately for Mark, it does not take much shielding to stop alpha-particles. Because of their large atomic mass, alpha particles are easily stopped by matter and can only travel a few centimeters in air. They can be absorbed by something as thin as tissue paper, or the outer layers of human skin -- which is approximately 40 micrometers thick, the equivalent of a few cells deep. Mark's RTG contains about 2.6 kilograms of plutonium and generates 1500 Watts of heat. Thermocouples positioned around the device convert 100 Watts of that heat into electricity.
This does not mean Mark should stop worrying. Pu-238 is still pretty dangerous. There is a reason why NASA does not want to put its astronauts next to glowing balls of death! While alpha particles cannot penetrate skin, ingesting or inhaling plutonium can travel deep into the body to irradiate internal organs. The element is accumulated in the liver and skeleton and becomes concentrated in those organs.
The unstable uranium-238 nucleus decays into a thorium nucleus and an alpha particle. The high-speed alpha particle loses kinetic energy and is converted to heat. Image credit: © Copyright CSIRO Australia 2004, via http://outreach.atnf.csiro.au/.
Fortunately for Mark, each plutonium pellet is sealed and insulated in graphite to prevent radiation leakage. Even if the seal is ruptured, Mark should be safe as long as he takes precautions to not breathe or ingest any radioactive particles
