[Edwina Lee (OP)]

To tackle the problem of space debris above earth, does it look practical to use ion gun satellites to shoot ions into orbits  so as to electrify small sized space debris, so that they would be slowed down by the earth's magnetic field and eventually burn up above earth?

[Bored chemist]

No.
Because there's already ionised gas etc up there from the Sun.
A charged bit of space junk would attract those ions and be neutralised.
Pity, it's an interesting idea.

[rhinegold]

Their are currently two competing methods for the clearing of space debris:

a) Physical orbital mitigation  see Clearspace and ESA and other companies.

b) Laser vaporizing of Space debris see Roscosmos. Patents have been filed by this organization with the European Patent Office. 

Professional translators warning:
========================
Great care should be exercised with Russian patents, as they are often poorly translated and claims made are without peer to peer approval.

[Bored chemist]

Great care should be exercised with Russian patents, as they are often poorly translated and claims made are without peer to peer approval.

A claim doesn't have to be true to get patented.

[rhinegold]

Thank you. This in my opinion  the problem with the current Patent System. But if you contact a university ( no names mentioned here ) to license their patent to you, just to find out that they have cheated, it can be a very expensive and demoralizing exercise.

[alancalverd]

Whilst a provisional specification can be published uninspected, a full patent will be refused if it contradicts the known laws of physics.

This is generally regarded as preventing patents for perpetual motion machines, but it might be considered unnecessarily restrictive if the inventor wanted to exploit a discovered but unpublished anomaly such as hole conduction or relativistic time dilation. In such a case the obsolete US requirement of a working model would lead to a patent even if the examiner couldn't understand how it worked, but the modern test of "sufficient detail for a person skilled in the art to replicate the invention" might fail it on the "known physics" grounds simply because the examiner thought he understood why it wouldn't work!   

A digression, but fun to debate.

[Petrochemicals]

Whilst a provisional specification can be published uninspected, a full patent will be refused if it contradicts the known laws of physics.

This is generally regarded as preventing patents for perpetual motion machines, but it might be considered unnecessarily restrictive if the inventor wanted to exploit a discovered but unpublished anomaly such as hole conduction or relativistic time dilation. In such a case the obsolete US requirement of a working model would lead to a patent even if the examiner couldn't understand how it worked, but the modern test of "sufficient detail for a person skilled in the art to replicate the invention" might fail it on the "known physics" grounds simply because the examiner thought he understood why it wouldn't work!   

A digression, but fun to debate.

You can get a patent granted, with resonable scrutiny from the office but it may not sand up in court, the patents may be augmented to achieve status and thus render themselves useless. Have you ever wondered how a patented product is so readily copied ?I always wondered about dysons patents, he himself liked to brag how he saw centrifugal seperators on vacuum extractors at saw mills