What stunned me, and many other, are the new weapon systems Putin has announced.
A more detailed discussion of fission weapon design is aided by introducing more carefully defined means of quantifying the dimensions and time scales involved in fission explosions. These scale factors make it easier to analyze time-dependent neutron multiplication in systems of varying composition and geometry.
These scale factors are based on an elaboration of the continuous chain reaction model. It uses the concept of the "average neutron collision" which combines the scattering, fission, and absorption cross sections, with the total number of neutrons emitted per fission, to create a single figure of merit which can be used for comparing different assemblies.
The basic idea is this, when a neutron interacts with an atom we can think of it as consisting of two steps: If the interaction is ordinary neutron capture, then no neutron is emitted from the collision. If the interaction is a scattering event, then one neutron is emitted.
If the interaction is a fission event, then the average number of neutrons produced per fission is emitted this average number is often designated by nu. By combining these we get the average number of neutrons produced per collision also called the number of secondariesdesignated by c: In computing the effective reactivity of a system we must also take into account the rate Questions on weapon systems which neutrons are lost by escape from the system.
This rate is measured by the number of neutrons lost per collision. For a given geometry, the rate is determined by the size of the system in Questions on weapon systems. Put another way, for a given geometry and degree of reactivity, the size of the system as measured in MFPs, is determined only by the parameter c.
The higher the value of c, the smaller the assembly can be. An indication of the effect of c on the size of a critical assembly can be gained by the following table of critical radii in MFPs for bare unreflected spheres: C is the degree of compression density ratio.
This scaling law applies to bare cores, it also applies cores with a surrounding reflector, if the reflector is density has an identical degree of compression. This is usually not the case in real weapon designs, a higher degree of compression generally being achieved in the core than in the reflector.
An approximate relationship for this is: Fission explosives depend on a very rapid release of energy. We are thus very interested in measuring the rate of the fission reaction.
This is done using a quantity called the effective multiplication rate or "alpha". The neutron population at time t is given by: The more familiar concept of "doubling time" is related to alpha and the time constant simply by: The time constant goes to infinity at criticality.
Alpha is determined by the reactivity c and the probability of escapeand the length of time it takes an average neutron for a suitably defined average to traverse an MFP.
If we assume no losses from the system then alpha can be calculated by: The "no losses" assumption is an idealization. It provides an upper bound for reaction rates, and provides a good indication of the relative reaction rates in different materials.
For very large assemblies, consisting of many critical masses, neutron losses may actually become negligible and approach the alphas given below. The factor c - 1 used above is the "neutron number", it represents the average neutron excess per collision.
In real systems there is always some leakage, when this leakage is taken in account we get the "effective neutron number" which is always less than c - 1. When the effective neutron number is zero the system is exactly critical. Ideally the value of alpha should be determined by "integral experiments", that is, measured directly in the fissile material where all of these effects will occur naturally.
Calculating tau and alpha from differential cross section measurements, adjusted neutron spectrums, etc.
In the table below I give some illustrative values of c, total cross section, total mean free path lengths for the principal fissionable materials at 1 MeVand the alphas at maximum uncompressed densities. Compression to above normal density achievable factors range up to 3 or so in weapons reduce the MFPs, alphas and the physical dimensions of the system proportionately.
In real fission weapons unboosted effective values for alpha are typically in the range doubling times of 2. All nations interested in nuclear weapons technology have performed integral experiments to measure alpha, but published data is sparse and in general is limited to the immediate region of criticality.
Collecting data for systems at high densities requires extremely difficult high explosive experiments, and data for high alpha systems can only be done in actual nuclear weapon tests.It is precisely anxiety about the loss of human control over weapon systems and the use of force that goes beyond questions of the compatibility of autonomous weapon systems with our laws to encompass fundamental questions of acceptability to our values.
A prominent aspect of the ethical debate has been a focus on autonomous weapon .
Frequently Asked Questions. Non-Lethal Weapons FAQs Active Denial System FAQs The Active Denial System will provide military personnel with a non-lethal weapon that has the same effect on all human targets.
Have there ever been any injuries associated with the Active Denial Systems? A Yes. Ponerology, the science of evil, rooted in secret investigations, objectively studies how evil deceptively spreads destruction, waste, neglect & suffering, taking over systems & how to oppose abuse, heal victims & develop healthy, sustainable systems immune to evil.
The concealed weapon application process: All applicants must complete an application in the Probate Court which is located in Room of the Chatham County Courthouse at Montgomery Street, Savannah, Georgia [Hyperlink: Map & Directions]. As many questions remain unanswered, the ICRC is calling on States to ensure that autonomous weapon systems are not employed if compliance with international humanitarian law cannot be guaranteed.
Share on Twitter Share on Facebook Share on Google+ Share on LinkedIn Share on WhatsApp. Questions on Weapon Systems. Topics: Weapon, Out of the many crimes that use IT systems, the one that cost us the most would have to be identity theft.
Biegelman states, “Simply put, identity theft is the stealing of your good name and reputation for financial gain.
Yet not everyone can agree on a suitable meaning of the term.