![[H]ard|Forum](/styles/hardforum/xenforo/logo_dark.png){kind=logo}
- Joined
- Mar 3, 2018
- Messages
- 1,713
CERN is shutting down the Large Hadron Collider for some significant upgrades later this year. Before it goes offline, researchers are trying to squeeze in experiments to answer an important question: does antimatter fall? Antimatter is the opposite of regular matter in many ways, but physicists don't actually know it behaves the same as regular matter in a gravitational field. There are several independent experiments underway to tackle the question, but they all involve generating neutral antihydrogen, letting it go, and watching to see if it falls down or up.
Check out a video on the Alpha-g experiment here.
ALPHA-g is very similar to the ALPHA experiment, which makes neutral antihydrogen atoms by taking antiprotons from the Antiproton Decelerator (AD) and binding them with positrons from a sodium-22 source. ALPHA then confines the resulting neutral antihydrogen atoms in a magnetic trap and shines laser light or microwaves onto them to measure their internal structure. The ALPHA-g experiment has the same type of apparatus for making and trapping antiatoms, except that it is oriented vertically. With this vertical set-up, researchers can precisely measure the vertical positions at which the antihydrogen atoms annihilate with normal matter once they switch off the trap’s magnetic field and the atoms are under the sole influence of gravity. The values of these positions will allow them to measure the effect of gravity on the antiatoms. The GBAR experiment, also located in the AD hall, takes a different tack. It plans to use antiprotons supplied by the ELENA deceleration ring and positrons produced by a small linear accelerator to make antihydrogen ions, consisting of one antiproton and two positrons. Next, after trapping the antihydrogen ions and chilling them to an ultralow temperature (about 10 microkelvin), it will use laser light to strip them of one positron, turning them into neutral antiatoms. At this point, the neutral antiatoms will be released from the trap and allowed to fall from a height of 20 centimetres, during which the researchers will monitor their behaviour.
Check out a video on the Alpha-g experiment here.
ALPHA-g is very similar to the ALPHA experiment, which makes neutral antihydrogen atoms by taking antiprotons from the Antiproton Decelerator (AD) and binding them with positrons from a sodium-22 source. ALPHA then confines the resulting neutral antihydrogen atoms in a magnetic trap and shines laser light or microwaves onto them to measure their internal structure. The ALPHA-g experiment has the same type of apparatus for making and trapping antiatoms, except that it is oriented vertically. With this vertical set-up, researchers can precisely measure the vertical positions at which the antihydrogen atoms annihilate with normal matter once they switch off the trap’s magnetic field and the atoms are under the sole influence of gravity. The values of these positions will allow them to measure the effect of gravity on the antiatoms. The GBAR experiment, also located in the AD hall, takes a different tack. It plans to use antiprotons supplied by the ELENA deceleration ring and positrons produced by a small linear accelerator to make antihydrogen ions, consisting of one antiproton and two positrons. Next, after trapping the antihydrogen ions and chilling them to an ultralow temperature (about 10 microkelvin), it will use laser light to strip them of one positron, turning them into neutral antiatoms. At this point, the neutral antiatoms will be released from the trap and allowed to fall from a height of 20 centimetres, during which the researchers will monitor their behaviour.
![Zarathustra[H]](https://cdn.hardforum.com/data/avatars/m/9/9298.jpg?1707758471){kind=avatar}
