 Τα στεγμή που εγγραφήσαμαι στις ασφαλήτων εξαιρίας με εξαστηριάτισμι. Τεχνί 20 λεπτά, είναι τώρα το κομμάτι της λαμπιστικής εξωτερίας που εξαστηρίζω στος λαμπιστικής λεγιάρου, Τώρα είναι πάνω από 5-6 χρόνια που είμαι ο Επιτουαστικής Κασμόνας για τη Κομμύτειο Φραδιές Προτεκτώνα, δημιουργίας της ετικουνίας της UCD. Από την κομμάτι που βλέπεις, η εμμάρια,1000 επόμενα εγγραφή μετά έλεγε, ή τις προβλήματα για να πω, που μπορώ να δώσω also ήißtη για την εερρήνη της σπίτις, ή δημιουργία της σπίτις, ή λασκότητας, ριθμό, κομπτήρετε μαςτα. Είναι δύσκολο να μξιωθεί, πώς είναι η δύσκολη, γιατί είναι δύσκολο. Είναι δύσκολο. Άρα, ήθελα να δώσουμε κάποιες πιστήρες για τη διεγραφία γιατί διεγραφία, γιατί διεγραφία, γιατί διεγραφία, κάτι σημαντικό κομμάτι. Γιατί διεγραφία, γιατί διεγραφία είναι part της αξιλίστας. Δεν μπορείς να βρεις ένα αξιλίστας, να το κάνεις γιατί θα το χρησιμοποιηθεί. explanation How you are going to manage. How you are going to face some problems. And it depends, of course, of the kind of accelerator, of the power of the accelerator, of the ions that we are going to accelerate. So the first thing is what's radiological protection and what is dealing with what? Radiological protection is a very complicated discipline και ο αδερφός που δημιουργείται για την προστασία, όμως για την οικονομική προστασία, για την προστασία, για την προστασία, για την προστασία, για να έχουμε κάποιο χαρμό για τη φυσική, την κεμιστοσύνη, η μυαλόγη, η λόγη και τα εταιρετικά κομμάτι. Όλα τα προστασία ιαλόγη είναι βέβαια από τρεις πρινσίπλες. Αυτό είναι ο καρδυναμός οικονομικής προστασίας. Η δυνατότητα της προστασίας δημιουργείτες, δημιουργείτες με μυαλόγη, με αδερφός αδερφός, αν πριν, προς την very beginning, δημιουργείτες, και δημιουργείτες ότι δεν μπορείτε να κάνετε αυτήν την προστασία, διδημιουργείτες, δημιουργείτες, δημιουργείτες. Δεν δημιουργείτες, να prac cage με πο galleries, να INTROκουλgangen οι θεωツές να τησίσει," Αυτό που λέμε μία θη 어�ού είναι για να επι nutrient to retain ...司 On, μ инструмент to consolidate after some years just to understand if there are changes in the knowledge. The second principle, δημιουργήσει τη δημιουργία. Πρέπει να κάνει κάτι, να παρακολουθεί οικονομικής και οικονομικής σχέσης. Πρέπει να δημιουργήσει να δημιουργήσει το σχέσης. Πρέπει να δημιουργήσει κάποιες σχέσεις, as they are considered, ότι they are far below the limits. Και η third one is individual dose limits that in any practice is someone, a person or a group of individuals cannot go over the dose, the limit of the dose that has been fixed. What is the main problem of radiation protection? The main problem of radiation protection is to define quantities that they have to quantify the exposure risk to the different type of ionizing radiation. What I have to know if I'm exposed to neutrons or gammas or a mixed field, what I want to know is what's the biological risk that I'm going to have. These quantities, therefore, serve as indicators of radiation risk and allow a satisfactory preventive structure to be given. That means that based on the quantities I have to think about what kind of a set I have to give. Which are these quantities? There are physical quantities, radiation protection quantities and operational quantities. The physical quantities are quantities that they are exactly measurable. You can measure them. The radiation protection quantities defined by ICRP are not directly measurable. It has to deal with average values and give you an idea about the biological effect and the operational quantities that they are defined by ICRU they are used for environmental and personal monitoring and on the basis of these quantities I can define the radiation protection quantities. The physical quantities, you know them, it's the fluence, number of particles per surface and the rate per second and this is perfectly measurable. The absorbed dose, that is the ratio between the average energy imparted or transferred by the radiation to the matter divided with the mass of the volume considered and the unit is grey, one joule per kilogram mostly used is the rate of the absorbed dose in grey per second or under multiple like milli grey per hour or micro grey per hour and so on. Then the Kerm of course that has to deal with non with indirectly ionizing particles like neutrons and gammas and it's the kinetic energy released in the matter defined by the quotient between the sum of the initial kinetic energies and all the charged particles produced by indirectly ionizing particles in a certain volume element of a specified material and mass dm and the unit is the same and passing to radiation protection quantities there is the average absorbed dose by an organ of the body or tissue and it's defined as you see as the average absorbed dose in an organ indicated by the DTR and this is the reason it's not a measurable quantity because you have to deal with an average absorbed dose in an organ that you cannot measure it. After this you have to deal with the equivalent dose that means that comes out from the question if I give an equal absorbed dose like for example one grey of neutrons or one grey of gammas what will be the biological response will it be the same or will it be different? The answer is that it will be different that means that the radiation have different quality for imparity of dose for biological effects and this is exactly saying by this quantity and by this product were if D is the same this one change according to the values of the waiting factor for radiation if you are in a mixed field of course you will have the sum the unit is severed or under multiples like micro severed per hour the rate, micro severed per hour or milli severed per hour and so on to pass to the next quantity the question is ok but if I gave the same dose to an organ, to different organs I will have the same response or not that means there is any different sensitivity, sensibility of the organs or are all the same to take into account excuse me before just take a look about what's the value of WR for photons and gammas by definition is 1 electrons 1, alphas 20, protons 5 and then on neutrons it depends on the energy having from 100 kV to 2 MAV a maximum of 20 and then goes down and then goes down the value of the waiting factor why because the energy of the neutrons is so high that did not see your body pass through without interacting so if the absorbed dose is equal to one grey and you have different waiting factors the equivalent dose is different and you have to multiply one grey with one of these numbers so you see that for photons one grey is one severed but for alphas is 20 and for neutrons depends on the energy you will have a greater number anyway going to the difference sensibility of the organs also here we have a waiting factor of the tissue of the organ according to his sensibility that means like before you remember this waiting factor for radiation now we have a waiting factor for organ for tissue or organ whatever and this value is different according to different organs of the body you can see it here according to ECRP 60 it's 0.20 then from bone marrow colon lung and so on and of course the total body is one these are the reminders that means different organs or tissue and every one of these is 0.5 on this column you see something interesting that have to be understood in the sense that if I have an exposed worker and we take 100 persons and they give him during their life one severed that is a very big quantity only 6 of them will have a fatal cancer due to the radiation taking into account that in a work dangerous like constructing buildings and go up in hate you have one death every 10.000 people working yes but these factors were measured experimentally or not they are WT you mean? WT coming out from calculation but also from the experience from radiation therapy during many years and also from workers that they are exposed in different miners and so on the ECRP quantities and GCRU quantities are non-measurable not measurable these data was collected over the many years no we will see how they do it I will tell you after ECRP 60 there is ECRP 103 some importance of the weight factor for tissue you see one of the most important is that the gonad goes down from 0.20 to 005 these are experimental results coming I mean you know that also from the survivors of Nagasaki in Hiroshima there are a lot of commissions that during years they review all the data and they give different values on a lot of things like weighting factor for neutrons weighting factor for tissues and so on I am coming to you to your question what they do really one is thinking about when someone tells me what's my dose the quantity is the effective dose and the effective dose is by definition non-measurable and the question is if it's not measurable what are you giving me ok but now we will see what is given to you in effective dose is something coming from here from the monitoring in the sense that your dose is related to ambient dosimetry that means I put near you a monitor so what I am going to take from the monitoring let's suppose what you got or I give you a personal individual monitoring so the read if I read it what I get is very close to what you got but not only what they are doing is if you ever read ICRP you will see that the job is done by Monte Carlo calculations they have the phantoms or ICRU sphere or other anthropomorphic phantoms like Adam Medeva where according to the type of irradiation that they have if it's direct irradiation or from the back to the front or lateral and so on they use these kind of phantoms and they make calculation about the dose they get factors that can they have to be multiply with the fluence to get the dose and what they know and this is according also to experimental data coming from a lot of facilities is that in all cases of gamma radiation except the part of the X-rays that they are near 30, 40, 50 kV in a mixed field you are always you are always underestimated the dose when you talk about effective dose only in the case of more energetic photons of 30, 40 or 50 kV you can have an underestimation of the dose and the same for neutrons because for you it's extremely difficult to find a place where you have more energetic neutrons generally out of the reactors, out of the accelerators you have continuous spectrum of neutrons and there they have except again some cases of low energy, more energetic neutrons you always underestimated the dose with effective dose so when you measure the operational quantities the protection quantities is always underestimated so in the process of radiation the source what you have personal dosimetry and you have ambient dosimetry in the environment what you measure with the monitors what are the quantities in these two cases it's the ambient dose equivalent what it said H star D and personal dose equivalent HPD this D it's not other than you measure the dose because when D is equal to 10mm you are considering penetrating radiation so gammas and neutrons in the case of D equal to 0.07mm you are talking about a skin radiation on the tissue because for example of soft x-rays and so on just understand what is ambient dosimetry you have to have in mind some definitions what is a real field, an expanded field an unidirectional and expanded field otherwise you cannot understand what is dealing about the ambient dose equivalent because the ambient dose equivalent by definition is the dose equivalent in a point and when you are in a point and not in the medium of a tissue you can measure in a point of radiation field that would be produced but the corresponding expanded unidirectional field of this urus sphere at a depth D on the radius opposite to the direction of this unidirectional field the recommended as I told you before distance is 10mm and this defined penetrating radiation in the case of directional equivalent dose Aka HD omega like solid angle you are talking about surface radiation and also radiation of the lens of the eye and you have recommended depth 0.07mm and you are dealing not anymore with expanded and unidirectional field but you are dealing only with the corresponding field in the ICRU sphere about personal dosimetry personal dose equivalent also here you have D with 10mm recommended as 0.7 for skin and eyes lens of the eye and the last one is what is going on when you introduce in your body your body radioactive material so when you introduce your body you are dealing with internal irradiation and so with effective dose that takes into account also not only external global or partial radiation but also the contamination in this case the quantity is the committed equivalent dose and this is with respect to time it's defined in a tissue or organ T that will be received by an individual and this kind of time from introduction up to the calculation of the dose is taking into account that it's 50 years so if someone introduce in the body let's say 1 bacharel of americium and one is saying for this introduction you got 10 microsieverts means that you got taking microsieverts from now up to when it will be 2069 ok if more than one organ is involved of course you have the sum of the committee of effective dose and of course this committed effective dose goes inside the total effective dose that is composed from external radiation and internal radiation if the internal radiation is zero because you don't have for example not shield material you will only have external radiation but if you have also introduction of radioactive material in your body you will have the sum external plus internal and the question is let's suppose that for example someone in a lab has no external radiation something is happening and introducing his body only radioactive material someone is making the calculation and saying you got 10 microsieverts ok another one is exposed to gammas or to neutrons only like external radiation and somebody is saying your effective dose is 10 microsieverts these two people that they get effective dose one from internal and the other from the external the same effective dose they have the same risk to get a biological effect or different risk because one is internal and the other is external must be must be why because if it's internal you have a very high probability of that particle interacting with your body what do you think you agree it has nothing to do it's the same from the definition of effective dose the effective dose like a definition if I go back the effective dose take into account whatever happens in your exposure internal external whatever it's the sum of all of your exposures it's a number that is related with risk so it doesn't matter how it comes out if it's because of internal or external exposure of course it's not taking into account the toxicity of the element because there is also the chemical toxicity of the element but it's not taking into account in this case once you have defined the effective dose you have defined everything that is related with your exposure internal external it is or the sum doesn't matter ok so this is important let's go down to see something that I don't know if you know about what are the limits there are the workers and there are the people the population, the public the exposed workers they have an effective dose limit of 20 millisievert per year at least in Italy that means that the exposed workers they have the same limit it doesn't matter if they are catalogized in A or B it's a question of other type of things let's say one can be visited by a doctor every one year the other one 6 months every year and so on but the limit of those that they have it's the same 20 millisievert per year non exposed workers it's not a very good definition that someone is not exposed to radiation is someone that because of his job he can take one millisievert per year and this is the same of the public then there are some partial limits on lens of the eye this is also changed with the new directive that considers the lens of the eye more stochastic effect and not any more deterministic effect and this value is from 150 becomes 20 then arm legs they have as you can see a very high value why they have a very high value because they have a weight factor for tissue 0.01 and then there is equivalent dose due to contamination due to exposure excuse me on the surface of the tissue and it's considered in one centimeter square where you can get 500 millisievert per year very often this is related if you have an accident with X-ray tube or something very focused like a beam on your skin and so on so these are the main limits that at least in Europe according to ECRP 60 are now in we working with them let's go one saying this part general part and we are going to see radiation protection at low energy from the proton accelerators because going to accelerators you have heavy ions it's another part but depends of course of the type of the ion energy and current but it's less dangerous in some way from the proton accelerators the overview of the presentation then what's prompt radiation the interaction of protons with matter nuclear interactions, characteristics of problem radiation field attenuation, this is extremely important for example to design your shielding induced radiative activity once your machine is working the activity when the beam is off remains induced radiative activity magnitude and prediction it's extremely important but you have to plan how to make maintenance on your machine then environmentally packed when you work like the phenomenon of neutron sky shining and that means the shielding of the roof of the accelerators, some aspects of emission of radioactive effluence and the summary what we call in radiation protection low energy and intermediate energy we are here up to 100 up to 1 JV maybe less to 1 JV of protons in energy then it's considered high proton accelerators the schemes of the accelerators that are very extremely different from earth use to first cyclotrons and very big cyclotrons like this one vancouver, then vantagraphs that you have already seen and DTLs and so on there are many applications of the accelerators from research to radiotherapy, industrial and medical radioisotoproduction waste augmentation like ADS and also detection of contraband you see a typical scheme here where from the reaction P on carbon 13 you have a gamma of high energy if I don't mind more than 8 MeV and so you can with this reaction you can you can search for contraband explosives and so on difficult to do it outside because all the farmers use a nitrogen for fertilizers so you can try to find bombs but you can find other things so I don't know what is the meaning excuse me the interaction of proton with matter the interaction of proton with matter low energy energy loss by ionization in higher energy you have energy loss by nuclear interactions in nuclear interactions you have diode interactions per equilibrium and equilibrium evaporation characteristics of the prompt radiation field there are, I'll give you some also equation or rules of thumb that can be interest to solve some quickly some to some problems that you can face interaction of protons with matter in low energy protons we define a range that in very high energy the range is not meaningful anymore the range is in iron you can see it here and for other materials you can calculate it from this equation the probability of interaction of nuclear interaction as you see here it's in the function of proton energy from let's say low energy sub 1 JV the probability is growing up and you see here the different materials where the proton is impinging on and you can arrive almost to 1 where at high energy every proton undergoes nuclear interaction if the target is thick enough so to stop the beam inside the target of course in the case of the protons that stop the beam inside the target we are referring also to black peak that is extremely interesting in application of proton therapy because you know exactly you know let's say exactly where you lose the maximum of the energy of the beam and let's go to characteristics of from the radiation field because when the proton interact with the target you have secondary particles that they are produced that they are going from neutrons up to gamma gamma rays passing from protons depending on the energy more than quite 500, 450 MAV pions, muons, electrons, neutrinos that they don't have charge and muscle they didn't give particularly problems in radiation protection and going to nuclear interaction you can see that the first part is the evaporation here with the direct directions up in energy this schematic spectrum of emitted particles and the energy spectrum of evaporate particles especially neutrons you see it's focused up to the first 8 MAV energy I mean when evaporation of neutrons coming out in a two step process first you have the particles that they are directly emitting from the interaction and then you have also neutrons coming from evaporation the neutrons coming out only from nuclear reactions then in these cases because they have charge you have energy loss by ionization the same electrons here you have no charge so you lose energy between the three processes that they are known and neutrinos practically you have no interaction and the interaction of proper radiation coming from an accelerator with the matter the most important thing are the neutrons in the shielding that goes they can penetrate very efficiently they have no charge and all the other charge particles they are stopped inside the thickness of concrete for example like in shielding so that's why often we say that when you have you have shielded the accelerator for neutrons you have also shielded the accelerator also from other radiation like gammas or charge particles because anyway they are arranged out like if you use adam meters of shielding against the neutrons for instance maybe you are using low weight material to shield the neutrons would you be shielding the protons and the rest as well yes yes yes but in an accelerator proton accelerator when you shield neutrons you have shielded also gammas if someone is going to ask me but why even if 3 or 4 meters of concrete I can find some gammas outside how it's possible or some neutrons if you have neutrons of high energy you have a probability that the neutron will undergo inside different interaction and some of them they can arrive just in the surface of the concrete with a thermal energy that can be absorbed for example from the material and when you create a nuclide that is excited then the gamma that's coming out will did not find a sufficient layer to to be shielded and so you have gammas in the same way even if you have 3 or 4 meters of concrete you can find neutrons outside because it's a statistical process some neutrons of high energy even if they go interaction they will have sufficient energy to go outside of the shield in a complicated situation for the shielding of accelerators you cannot use any more ncrp51 even if it's a very good book of reference book but in the scheme complicated of shielding you have to use Monte Carlo codes without Monte Carlo codes it's not anymore possible to work most of them like mcmp or mcmpx or higher energy than 20maV or light or fluca or mars they are doing different jobs or they use different nuclear models but they are they are the tools that they have to be used anyway here you see an example for example a 30maV radioisotoproduction from a cyclotron and in the different colors done in a geometry that you create inside the Monte Carlo you can have an idea let's say in the point of interaction of the beam what is going all around your shielding once you have defined the thickness of the shielding and you can have an idea what's the rate that you can expect when you are dealing with shielding calculations and remember always that the pen of the paper and by your hand I mean it's always valuable in some situations the main equation for shielding is this one where this is the dose rate that I need but the ambient the ambient equivalent dose rate for neutros for example that I need, the energy of the proton the angle between the target here is the proton beam and I want to know what's going on here this is the angle and this is the reference value of the dose that means what's the dose that I have and then you have the lambda that is the mean free path and and this is the distance between the proton beam and the target the point of the source and the point of my detector, the point of interest and always and as we'll see these numbers lambda is already calculated for most of the cases and so you can find it in the literature in the case in which you have a shield and you want to know something in this 90 degrees this name test is a famous German radiation protection man that you can search in internet and you can find his publications so at 90 degrees from the source what you have is this expression to calculate the dose and this cascade it's not other than this value that you can calculate it expressed in pico-sever in the fraction of proton energy also this value density multiplies lambda in concrete here and as you see many people have made calculations and they are very near to this curve so they are dose attenuation length in the fraction x-axis you have the proton energy in MAV here you have also a value of density multiplying lambda 10 but lambda 10 is not other than 10th value later that means that means the thickness from 1 to go to 1 tenth of the dose and you see for various reactions that are type PN or DN or helium 3 N reactions where they are in function of the particle energy here we are here you have some equivalent formulations of dose attenuation that means reference at one meter and what I have what I need or what I want to have so that I can calculate my thickness of the shielding and you see attenuation length half value layer and 10th value layer and these are the relationships between them this is the dose attenuation length in concrete given by NCRP 51 and also by other researchers that they have made the calculations dose attenuation length versus proton energy and this is a famous coming from also NCRP more recent about accelerators that give you the neutral attenuation length up to the higher energy limit where you arrived at a certain value where you don't have any more and increase and let's pass now to radioactivity induced in target and structures just two rule of thumb just to have an idea in accelerator the saturation activity coming from 0.1 to 1 megawatt that means multiply energy with current of the accelerator you are near to 110.000 tbk that means 6 tbk per kW when in efficient reactor the at saturation you have 50 tbk per kW of power residual fields of components in total radioactivity produced in thin targets you have here some some ideas what you are going to expect per proton current in bkg per square centimetre and in the range of current from 1 to 10 when you go up from 1 to 10 micro amp of current when you are in some tens or hundreds of maybe remote handling of the piece that is activated is needed and of course this goes up with the cost of the facility how I can determine induced radiation field I don't know if you know this guy of 1950 50, 50, 54, 55 barbie you can find the book in internet there is an extremely detailed procedure how you can go to calculate the total dose rate starting from the input target element or compound activity from cross sections look up gamma ray library flaxes and so on and so you have an idea what kind of activation can you expect in different cases in different materials how can you determine induced radiation fields in experimental way if you have a monitor and a chamber you can measure the total dose rate from the piece from the block of whatever it is then if you have a high pure germanium and you shield it just to take only the part that is coming from the activated part you have the gamma spectrum and going all around this procedure you can have the possibility to calculate the induced radiation fields for arbitrary radiation history and this is useful for what for shutdown and maintenance planning and for decommissioning planning of your facility for example here is a 500 mebsyclotron exam coming from triumph where they have they have here the rate in milli grays and the time in days and here you have the beam current in micro amps and the last part is the two an extremely interesting part on environmental impact including sky shine of radiation and release of effluence in air and water what's the sky shine you know that if you don't have a shield up your facility and you have a high production of neutrons the neutrons from the source coming out interact with the air and you can find your neutrons your detector in a certain distance from your facility that can be also hundreds of meters away this is because you have the interaction of the neutrons in the air with nitrogen oxygen and so on and this as you see these cross sections are not so low especially when you have high energy neutrons you can have distances that goes up and up meanwhile low energy neutrons can stay inside this sphere in first approximation the dose that you are going to have in a certain distance is this is the source term in neutrons at the point of emission and in a certain distance you will have a dose rate coming from this equation the spectrum of course hardens with the distance if you have high energy neutrons as we said we will find them very far away so be careful we need all ways to have to calculate the shielding at the roof of our accelerator otherwise you will find problems and if you are in a situation that you cannot shield with blocks your target inside the room you will have a lot of problems because you could not anymore put a roof at the roof but you will have to keep the distance of your building emission of radioactive effluents near water since this thing this is dealing with a typical active cooling water system where you have a high active circuit cooling circuit coming from a target collimator and here you have resins that exchange this is a double system closed exchange the water with the resins of course tritium is not is not absorbed with the resins because hydrogen in the water and you can keep only this kind of radioactive elements to create inside the water and then there is another active of low conductivity water another system that gives cooling to beam line magnets, vacuum pumps cavities and so on that is made in such a way that you can also evaporate the water and leave the radioactive the radioactive elements inside this containment because the water evaporates of course and the radioactive parts remains inside in the case of some kind of losses of the material it has to be you have to think about a containment where the water can finish because will be activated and show a closed sample and all these things to create them is not, you have to foreseen before because otherwise it's not so simple to create after in the facility a typical design of drain system is this one where there are different as you see some from a local to a central so on with level alarms when you arrived at a certain height there is a level alarm you can measure here if you don't have if you don't have so much of the activity is decay you can set it to the central active somewhere it can remain stills with level alarm in case you can take some of him you can take it out and if you don't have you are under the concentration of the activity that the law of the country where you are permits you can also throw it away this operation in Italy is extremely strict you cannot send anything that it's overrun bacharel per gram so it's quite nothing and the last last transparency is with with a vacuum exhaust system complicated especially in facilities where there are objective beams where there is a two barrier vacuum a primary one and the secondary one and then storage tanks where the pumps along the beam or from the source or from the secondary vacuum takes the gases and they put it in these tanks where you can calculate the time of decay and then to put some of the gases to another and to another one waiting long term period so the radioactivity high level can decay and so in a certain way you can throw it away or by using HEPA filters for particulates or if you are in the presence of iodine or of halogens that they are radioactive or you can use charcoal filter to trap them and then if it's permitted the measurement that you do before the chimney permitted you can send it to the environment where exactly here well here the primary vacuum is the vacuum of the target but what's the radioactivity for example in the rib facility you have fission you have everything you have everything means all the iodine if you make fission from neutrons on uranium for example it's the same as you do it by protons the same means you can have some difference in the fission curve it could be more and ten way more going down or more flat but you will have all the krypton the xenon the iodine the halogens but in terms of radioactivity normally when you make a nuclear reaction the amount of particles that you are generating is let's say in the order of 10 to 8 in this case I can tell you that with 35 grams of uranium carbide you can have a thousand and irradiated 14 days with protons of 14 maV and 200 micrograms you have 10 to 13 fissions and you have 1000 queries after 14 days of irradiation the number for example of of noble radioactive gaseous that you produce is 10 to 13 so it seems but it's enough this is important generally speaking when you have the possibility to have release of radioactive material you must be under pressure or better you have to create at least two barriers of under pressure for example in our case in our lab in our facility for what we are doing we have main in the bunker of irradiation minus 80 Pascal in the room before minus 40 and then atmospheric pressure so if you are going to lose a barrier there is another one otherwise the activity is going around and this is what is what is sketching here radioactive air you are in low pressure to create low pressure you have to have a fan that takes out the air to create the under pressure so the question is this one how many number of air changes I have to do a lot in an hour for example or not the answer is here from these two graphics where this one you arrive to one because as fast as you take it out it is creating and you see that high refrigeration rates reduce the reactivity level in the room where you produce it but you go up increase with the amount of reactivity that you are bringing outside of the facility so you have to find the gold number where you are creating the pressure that you want with a minor number of air changes this is a mathematical approach that if someone of you is interested we can change it you can send it to you so you will see exactly which are the equations and how you face it so in summary we have described some specific application proton therapy direct interactions of operations shielded and mediate energies semi-empirical types measurements sky-side emission effluents remember that when you have when you have a reaction with a proton beam impinging on a target most of the time it is in the direction of the beam that you will have concentrated the major number of neutrons in the case of the evaporation of neutrons because of the excited state of the system the evaporation is going of the neutrons with maximum manager of FATMEV it's going to be distributed in an isotropic way and not pick up in the zero degree direction compare it with a beam ha! I go out at least 15 minutes please I'm wondering my first question is what is the timeline of a timeline of a central nuclear reactor central when you have a facility but how long how long it lasts first and do you include into the system of radiological protection the commission the commission this is a very interesting question I don't know if you heard what he said he said if you have a facility a radiation facility of a certain importance radiological importance how long this facility is designed to operate and of course if you have to think before about the commissioning of the facility this is an extremely important issue not only how to manage it after but also from the radiological point of view when you create a facility at least you are thinking to make it work at least for 30 years especially if it costs millions of euros taking into account that a nuclear reactor is thought to to work about 30 years but then nobody stop it so they go they take periods of 10 years 10 years to go to go on so this is the first part the second part that is not second but it's also first of the first is when you construct a facility you must to think immediately about the commissioning of the facility and this is asked for example from the Italian law to make a plan or how you think to the commissioning of the facility why in our case for example when you have 40 MAV of neutrons 40 MAV of protons with 200 micrograms 10 to the 14th neutrons impinging on the walls of a bunker first then you have uranium carbide inside there so you have fission you are able and you are so um let's say technically good to confine all the material but it's not the case because some of the material we are going to lose it all around the bunker so you have to think how can there are any actions that I can do from the very beginning in the phase of building the facility so to make the costs less and the answer is yes for example in Italy you cannot throw away concrete that it's activated and if you go to search in the literature you will see what you imagine that concrete produce because concrete is made carbon hydrogen and some element trace element materials one of the strength element material most important is europium europium change in europium 152 that has half life of 12 years or so on so when you create europium inside the concrete and you have so low concentrations of one becquerel per gram otherwise you cannot throw it away you have to keep it so you have to think that if I make a wall all together of 5 meters of 4 meters or 3 meters then what I'm going to make this kind of wall but if I can calculate with Monte Carlo after a certain period of time like say 20 years with 5 or 20 thousand hours a year of operation I can calculate up to what thickness I will have this kind of products so I can build my shielding in slices so if I know that up to one meter and a half I will have this kind of problems after that if I make a slice of 1.5 meters and then another one it remains and the other throw it away I make something else not only but in our case of radioactive beams when you will have contamination and you have also alpha contamination because there is a fission inside there you have also neptunium you have also other things that they are alpha emitters if you lose it in the concrete downstairs it is going to go inside inside and you cannot take it out in the contamination anymore but if you think to paint the whole bunker with appropriate material that it is easy to decontaminate it then you will take it out when you finish your facility and the other thing will be clean otherwise you are going to spend so much money that you cannot imagine that the commissioning is one part extremely important from the money point of view can cost more than the bill thank you