Company: DRTSW
Filing Date: 2025-03-12
Form Type: 20-F
Source: 0001213900-25-023187
Chunk: 116

Company: Alpha Tau Medical Ltd.
Filing Date: 2025-03-12
Form: 20-F
Item: Item 4
Chunk 116
---
 the excess energy stripped, will spin off into a new element, or a daughter atom.
If this daughter atom is itself unstable, it, too, will shed its excess energy and generate its own daughter atom, setting into motion
a decay chain until full stability is ultimately reached. While it remains unknown how long it will take an individual atom to fully stabilize,
we can quantify how long it will take, on average, for half of a given quantity of an element to decay: known as a half-life, which
can range among different radioisotopes from as little as infinitesimal fractions of a second, to billions of years.

Alpha, beta, and gamma radiation

Specific radioactive elements
will consistently undergo one or more types of radioactive decay with their own, fixed characteristics, and can result in the release
of particles or photons. For example, the element Radium-224 will undergo decay by shedding two protons and two neutrons (an alpha particle),
generating the element Radon-220, and in so doing, emit energy during the release of the alpha particle. This process is known as alpha
radiationor alpha decay, and the alpha particle, bearing the mass-heavy, sloughed-off protons and neutrons, will itself be
heavy (with an atomic mass of 4). By comparison, one form of beta decayoccurs when an element emits an electron, with a negative
charge and a relatively low mass. Alpha particles are far bulkier and slower than beta particle electrons: over 7,000 times heavier with
approximately 200 times the linear energy transfer rate.

Alpha and beta particles,
being charged, interact with the charges of every atom they encounter and continually slow down as they travel. Because alpha particles
have such a high mass and linear energy transfer rate, they dissipate their energy quickly and are unable to penetrate most surfaces,
even as thin as a piece of paper. Alpha particles therefore have no clinical impact when delivered externally, since they cannot penetrate
the skin. On the other hand, beta particles are more nimble than their alpha counterparts and can penetrate further into matter; however,
because they have equally low mass as the electrons they encounter, beta particles transfer their energy and also fade quickly when encountering
a surface of some thickness, such as being stopped by a sheet of aluminum.

Gamma decay, by contrast,
does not involve any transfer of charge but rather a reconfiguration of the existing subatomic particles, triggering the emission of high-energy
photons in the form of gamma rays