AZING: 3e11 GeV Protons Discovered in Utah Sky

[Andrew Mason]

http://www.symmetrymag.org/cms/?pid=1000063&printable=1 describes detection of cosmic rays with unbelievable energies:

At 3x1020 electron volts (a 3 followed by 20 zeroes), the particle that hit the Utah sky in 1991 was 300 million times more energetic than those made by Fermilab’s Tevatron, the world’s most powerful particle accelerator.

This is a proton with 20 joules of energy - about the same energy as a well driven golf ball in mid-flight.

The thought occurred to me that (if we can figure out where these particles are coming from, which appears to be a goal of the project) perhaps we should be building some big particle detectors for SkyLab rather than building bigger terrestrial particle accelerators.

AM

 

[Davorak]

I had heard of those experiments before but not of the 3x10^20 GeV particle.
From:
http://www.cosmic-ray.org/reading/uhecr.html
Cosmic rays with around a joule or more energy are call Ultra-High Energy Cosmic Rays or UHECR.
Also:
http://auger.cnrs.fr/presse/ScAm_jan97.html

 

[ZapperZ]

http://www.symmetrymag.org/cms/?pid=1000063&printable=1 describes detection of cosmic rays with unbelievable energies:

This is a proton with 20 joules of energy - about the same energy as a well driven golf ball in mid-flight.

The thought occurred to me that (if we can figure out where these particles are coming from, which appears to be a goal of the project) perhaps we should be building some big particle detectors for SkyLab rather than building bigger terrestrial particle accelerators.

AM

People have wanted to build a high energy physics experiment using cosmic particles for at least a decade now. The problem that most of them seem to overlook is the complexity and the SIZE of the particle detectors! Have you seen CDF at Fermilab? It's the size of a HOUSE! And not only that, it is built with such precision and such utterly ridiculous tolerence, I cannot imagine it being built in space, or being rattled off upon liftoff to be put in position.

The other issue being the fact that you cannot control where these particles are coming from, and so the ability to control the trajectory is almost non-existent. Couple that with the uncertainty in the luminosity of the particle you want to collide, and we have way too many unknowns to convince the taxpayers to fork over the gazillion dollars to pay for such thing (after all, they've already been suckered into paying for the ISS with practically no science value whatsoever in return).

So yes, you do get the energy for almost nothing, but you also lose a lot of other control and capabilities in return.

Zz.

 

[Andrew Mason]

.So yes, you do get the energy for almost nothing, but you also lose a lot of other control and capabilities in return.

All very good points, of course. But my comment was driven more by the fact that these kinds of energies are unattainable on anything that can be built on Earth (or likely in the next few hundreds of years), rather than the cost of running an accelerator. Does a detector have to be that large to measure anything useful from a 3e20 eV proton?

AM

 

[ZapperZ]

All very good points, of course. But my comment was driven more by the fact that these kinds of energies are unattainable on anything that can be built on Earth (or likely in the next few hundreds of years), rather than the cost of running an accelerator. Does a detector have to be that large to measure anything useful from a 3e20 eV proton?

AM

Considering the amount of garbage... er... shower of particles that will come out of something with THAT high of an energy, I predict the detector has to be the size of several houses.

And just to prove the point, the ATLAS detector being built for the LHC at CERN is the size of a 5-story building!

http://atlas.ch/etours_exper/etours_exper01.html

Zz.

 

[joshuaw]

Is it even feasible to attempt due to the radiation length of some of these excited particles. Besides the hadronic showers as ZapperZ mentioned(which is a problem at FermiLab I believe), I would believe that the acceptance in such a detector would be too "small" to justify this.
If you look into the CLAS detector at JLab, size is not the problem. It is whether we can track and ID particles in these detectors. Electronics seems to be the limiting factor at this time
Josh