There are a lot of force field guides out there at this point, and I don't feel that I have anything to add to that general base of knowledge, but there were some initial complaints about my first ff/rad guide that discussed FF from a /rad secondary perspective, rather than going into detail on the rad power set. I've decided that, while another general FF guide is unnecessary at this point, a more specific FF/rad guide+build may still be of benefit to someone.
The last guide was a bit long and detailed, so I'm going to keep this straightforward. First I will describe the build and playstyle, secondly I will briefly discuss each power and why I did or didn't select it, and third I will post the build itself. At the very end, I will present a couple of specific tactics to use with this build.
FF/rad - hybrid defender
Force Field
Force field is a power set that has swung back and forth on the effectiveness scale, but the "feel" of the set has undergone relatively few changes over the past 2 years. The easiest and most commonly appreciated aspect is its defense bonus. Through two fast recharging long duration clicks and one wide radius toggle, we can single-handedly cause the majority of attacks against our team to miss, and also protect them against most status effects (which generally miss anyway). The degree to which we succeed at this roll has changed from time to time, but basically it is a fairly passive role. Keep the bubbles up, try to keep people without mez protection in your big bubble, and basically do what you want besides that.
The second aspect of FF is its soft control through knockback, positioning, and phase shift. We have a single target kb, a target aoe kb, a pbaoe pulsing kb. We also have a large aoe repel, and a single target (enemy) phase shift. This requires a more active role in combat, positioning, luck, and frequently an experienced team. These powers also tend to draw agro from a very large number of attackers, against whom we are ill suited to protect ourself without depriving our team of a portion of their defense and taking away our ability to do very much.
As a player, I - 1. Enjoy solo play, 2. Don't have a regular team, and 3. Frequently join PUGs with people who may or may not be ignorant of how to support a soft control FFer. Because of these things, I found that I was able to get the most mileage and enjoyment out of my character by largely disregarding the soft control element of the set. I chose to focus on the powers that were both constantly useful and did not interfere with me blowing stuff up. Niche powers generally got the axe, with a couple exceptions (force bolt and detention field.)
Radiation Blast
As far as rad blast is concerned, I focused primarily on single target powers. The reason for this is two-fold. First, the endurance efficiency on the aoe attacks is very poor, and when coupled with defender level damage is a very tiring way to tackle solo spawns. Secondly, the recharge is somewhat prohibitive, especially since hasten is mostly unnecessary as a FFer. Keep in mind that this approach may not be applicable to all play styles. A character who does not solo may find neutron bomb to do more total damage than x-ray beam, or may not frequently use proton volley, but as someone who likes to do a bit of everything, I found that the extra damage I brought to a team with neutron bomb or electron haze wasn't not significant enough to compensate for the inconvenience of using them to do solo missions.
Bringing It Together
This build will not be fantastic at anything. It is sort of a jack of all trades, master of none approach. Force field enables this build by allowing us to protect a team quite well with very minimal time and endurance cost, but on the other hand, it also doesn't contribute very much offensively. There is a certain balance to this, however, as other defender power sets are not nearly as forgiving. A rad emission who loses track of his toggles by spending too much time blasting becomes much less able to defend the team. Storm, kinetics, TA all rely very heavily on click powers, requiring constant attention, and frequently interrupting attack chains and draining endurance. These are broad generalizations, of course, but the point is that while FF doesn't provide any offensive bonus, it lets you protect the team with less time and endurance expenditure than any other defender set.
Because of this freedom to attack, I feel it is a waste to play a FF who neglects their offensive set. This build is heavy on attacks. It is designed to offer the team as much benefit as possible while still firing off a constant stream of damage and defense debuffs (enabling your teammates to hit more often as well.) Solo, it plays like slow blaster with good defense, mez protection, high accuracy, and a near guaranteed get out of jail free card. On a team, you give everyone defense and reduce enemy defense (and later through leadership give more defense and accuracy.) You may not be fully appreciated, as players will still miss, and enemies will still hit them from time to time, but you are a solid group facilitator, and do not require any particular group tactics or intelligence to apply the majority of your bonuses.
Lastly, as a force fielder, I have this vague notion that I should be able to have fun in PvP. Unfortuantely, the powers that are notorious in pvp (primarily the last 3 in the set) are really not very useful to my playstyle outside pvp, so my compromise was taking force bubble at 49, for when the level 50 pvp zone comes out. This build is not really prepared for level 38 pvp, though it does have tactics, force bolt, and a decently slotted personal force field. If you want to spend the majority of your time in pvp, however, I would reccomend a build more suited to the task.
Powers
Note: Due to the wide variety of character builders out there, and discrepancies between stated numbers for powers from different sources, I will not be including power numerical values. Check out some character builders and decide which one you prefer to use. Since I am providing a build, I will also not be "rating" the powers for this guide, or reccomending specific slottings for all powers.
Force Field Powers
Personal Force Field
Offers fantastic personal protection at the expense of being able to do anything else. Will not drop your toggles, but prevents you from using any powers on targets besides yourself, and prevents your toggles from affecting anyone but you. You can use aid self while in the bubble, but using the "rest" power will turn off pff. Useful for travelling safety, avoiding team wipes, absorbing an alpha strike, hiding out after you nuke, and generally staying alive when most defenders have to run. Activation time is a little slow, so it never hurts to fire it off a hair before you are actually in mortal danger. Doesn't ordinarily need more than 1 defense enhancement, unless you plan on using it in pvp.
Deflection Shield
A staple of team defense. Useless solo, but gives significant protection to the target against melee and smashing/lethal for 4 minutes. Recharges fast enough that you don't need any enhancements besides defense.
Force Bolt
Solid soloing power. Sufficient to knock over 1 enemy, including most bosses. I don't know if KB has a magnitude the same as other powers, but I find that there are some enemies that can be knocked over by other powers (like telekinetic blast) which seem to resist force bolt knockback. Aside from what appears to be a somewhat reduced "magnitude" of knockback, this thing is great. Needs at least 1 recharge to be able to keep a single enemy constantly on their butt. Accuracy is pretty good to start with, but this is a power you never want to miss, so another one never hurts, and if you use FB/snipe against bosses, the sheer quantity of FBs you use usually warrants an end rdx, in my experience. Can knock off toggles in pvp, which is nice.
Insulation Shield
Same as deflection shield, but for ranged and non smashing/lethal damage.
Detention Field
Not the most exciting power in the world, this puts one enemy into a detention field for about 30 seconds. Actual game effect: single target phase shift and immobilize. Immob resistant enemies will still be able to move, but not attack. The drawback here is that the target is immune to all other powers while phase shifted. Teams tend not to like this power a whole lot, but in groups of 1-3 players, it can be invaluable. Useful for tackling any spawn that has an undesirable enemy - sappers, nemesis LTs, an extra boss, a paragon protector who went MOG on you (jerks.) Solo, detention + force bolt can allow you to basically face only 1 enemy at a time out of a 3 mob spawn.
Dispersion Bubble
Area effect toggle centered on you with decent defense bonus and protection against hold, immobilize, and disorient. This is really a great power that you probably will run every minute you are in the game (save for when you've been put to sleep grrrr.) Probably you will want to slot it with 1 and maybe eventually 2 end rdx, and 3 defense.
Repulsion Field
Area knockback away from you. Not as expensive as it once was, but it still isn't very useful unless you're trying to pin enemies against a wall with it. Solo, it's not necessary if you have force bolt, and in a group it is difficult to get pick up groups to coordinate with this power. I tried it for awhile instead of force bolt, but when you're holding 1 enemy in the field constantly, you do lose endurance quickly. Decent in pvp as it can deter stalkers and drop toggles, but also will drain your end like no tomorrow if you're at melee with someone who's knockback resistant.
Repulsion Bomb
Area knockback targetted at an enemy. Despite targetting an enemy, the knockback is away from you, which means flying above enemies allows you to sort of knock enemies down, which is slightly less offensive to a team. This power has a small chance of a low magnitude disorient, which I used to reccomend you stack with cosmic burst to stun bosses. It's not really reliable for that purpose any more, thanks to the low chance, and the long recharge. I've also tried to use this power as a supplement to force bolt, or an area effect force bolt, but the long activation time and greatly increased recharge time basically means that this is an agro magnet. Great for dropping toggles in pvp, and occasionally useful for knocking down a few enemies every 30 or 40 seconds in a team, but I just can't reccomend it any more.
Force Bubble
Huge area repel away from you. Occasionally knocks down enemies in the radius of effect (like 5% chance, very small.) Similar to repulsion field in that it is unnecessary solo, and very difficult to effectively apply in a team setting. Occasionally you will be able to put it to use against large groups of enemies with poor ranged attacks, but generally you have better ways of defending a team. One option is to flick it on, then off, and go into personal force field, to take some heat off the rest of your team. You also can use it to zip around a room, agro everything, then hide behind a wall and go into pff. I mostly use this to pull a group together prior to nuking. Decent scrapper deterrant (anyone without repel deterrant really, in pvp.)
Radiation Blast Powers
Neutrino Bolt
Low damage, fast activation, fast recharge power. Decent dps alone, "ok" contribution to attack chain. Occasionally proclaimed to be good enough that you don't really need other attack powers to make a good attack chain, but some number crunching will show that that's not really the case. It is true that you can survive without other attack powers, but as a soloist, I like to have more than JUST this in my single target arsenal. Anyway, you have no choice to take it or not, so slot it up and it's not bad.
X-ray Beam
Not a bad power. Single target with slightly better damage and slightly longer recharge than neutrino bolt. Comparable to power bolt, charged bolts, and most other moderate damage low level blasts. Works well to fill the gap between neutrino bolt for a decent increase in damage output early on, plus it shoots green lasers out of your eyes, which is pretty cool.
Irradiate
Area effect damage over time attack centered on yourself. Total damage equals that of x-ray beam, approximately, and endurance cost is slightly less than 4x as much. That means this starts to be an efficient attack with 4 targets, and it also applies a very hefty defense debuff for about 30 seconds! Overall a good power, but it can be draining to use solo. Super fast activation time though, so a decent precursor to a nuke, and easily able to be used to zoom in, debuff a group of enemies your team is fighting, and zoom out.
Electron Haze
Highest damage power so far in the set, basically made a pain thanks to its narrow cone, inconsistent knockback, high cost, and lame activation time. In the right hands, this power can still do some good damage, and starts to be efficient around 2-3 targets, but as far as dps goes, it isn't really that great. Against a single target, you can fire off nb and xray for the same activation time of 1 EH, doing almost 20% more damage and spending half the endurance. If you are consistently fighting larger groups, it becomes worthwhile, but I always seemed to have better powers to use.
Proton Volley
Our snipe. Not bad as far as snipes go. Doesn't usually hit the enemy until the animation is done, so you can usually duck out of sight by moving right before the firing animation begins and avoid getting more than 1 enemy. Looks kind of amusing. The defense debuff works well with a snipe, because it makes following up after the snipe pretty easy. It has a very long activation, but recharges faster than electron haze. I kind of think of it applying a little more than 2x electron haze damage for approximately 2x the activation time, but costing the same and recharging faster. So I picked proton volley over EH, since I prefer finishing off single targets quickly as opposed to having to face the full amount of enemy damage until eventually killing them all at once. Dispersion bubble, force bolt, and cosmic burst regularly allow me to use PV in normal combat settings without being interrupted.
Aim
Really a must have for an offensive defender. Useful in two ways. First, it's up pretty often, and is a solid improvement to overall damage and accuracy. Secondly, it gives us a "must hit" guarantee on certain powers. Don't bother slotting accuracies in your nuke, because aim will always come first. When you need to apply that defence debuff with irradiate on critical enemies, aim will be up. Needs a couple recharges usually, but hit buff is not necessary.
Cosmic Burst
Finally a real combat power. Better damage than anything so far, plus a nice mag3 disorient. Range is short, but that's not usually a problem. This is simultaneously the third prong of your defense, and the lynchpin of your attack chain. More details in the tactics section.
Neutron Bomb
Area effect damage targetted on the enemy. Kind of a disappointment. It's like m30 grenade, minus knockback, with higher end cost, 29 circle later than an AR blaster would get it (and I never found m30 to be that useful to begin with.) Pros: looks cool, can hit a group of enemies from far away, cheaper than irradiate. Cons: Sad damage (less than irradiate or x-ray), harder to position where you want than irradiate, slow activation. I would only reccomend this for a "group only" character.
Atomic Blast
Arguably one of the better nukes in the game, and the one to truly deserve the name "nuke" heh. Atomic blast is very solid damage with a nice mag 3 hold on top. It does no knockback, which means even if you don't kill everyone, you haven't moved anyone out of place for futher aoe follow up from your teammates, and the hold helps keep you from getting pilllaged by survivors.
Power Mastery Powers
I chose Power Mastery because it seems to best complement my playstyle, so I have included the powers from that ancillary set only.
Conserve Power
Reduces your endurance cost by half for a little while. Long recharge. Unless you go all out AoE, this is pretty unnecessary. FF drains very little end, and single target rad blast is pretty managable as well.
Power Build Up
Look Ma! I'm a real blaster! Gives you a boost similar to build up, and also double the duration of your secondary effects for about 10 seconds. Works well prior to aim (since it buffs aim) and then before either irradiate (for the defense debuff) or atomic blast (for damage and the hold duration). PBU + aim + atomic blast can drop yellows and oranges pretty frequently. Also works well before cosmic burst if you're fighting a boss. You can usually get off 2 bursts before PBU wears off, which should keep the boss disoriented for a nice duration.
Temporary Invulnerability
Reduces smashing and lethal while the toggle is up. Worthwhile, but not exceptional. Helps to take the edge off, but hardly a license to tank. I chose it so I can get total focus.
Total Focus
Well, you may only have 3 circles left to 50, but you finally got another good single target power. Works great with cosmic burst to disorient multiple opponents in a row. Long activation and recharge, but a solid choice all around.
Explanation of some slotting decisions:
Most attacks were slotted acc/3dam/end/rech. This can be adjusted as needed, depend on how you use your attack chains, and how much end you find that you use. Cosmic burst got 2rech and no end, since the damage output is so good, and stacking disorients is very useful. A daring player could drop accs from all powers, put more tohit into tactics, and rely on the def debuff from rad to improve their accuracy, but I slot 1 accuracy.
Force bolt, and both individual shields got an end rdx to compensate for running leadership toggles and TI all the time, but depending on what toggles you use, they may be unnecessary.
I didn't slot more tohit in tactics because radiation blast is usually not missing after my first hit anyway. I have aim for when I NEED to hit, and 1acc in all powers anyway, so I decided I didn't need more in tactics. YMMV
Detention field needs 2 recharges to have ready by the time it wears off, and forcebolt takes 2 to comfortably have ready whenever I want it. I put an accuracy in both because they both are powers that can cause a lot of pain if you need them and miss.
Lastly, these are endgame slottings. Your slotting with TOs or DOs should not be the same as this, and some powers may be slotted in a slightly different order than presented.
Tactics
I'll keep this brief.
Defense tactics:
Keep your team bubbled all the time. It's really the best you have to offer, and if you let it slip, you risk things falling apart with no way to "recover." Try to keep the dispersion bubble around controllers, defenders, and blasters, and generally run leadership toggles most of the time. In a team, reserve force bolt and detention field for emergencies, or enemies that are not part of the melee fray. Solo I like to use detention field on bosses while I clean up the minions around them, though generally I don't use it on EVERY group. Generally I use cosmic burst as my primary defense, force bolt as secondary, and detention field as last ditch. Dispersion bubble is my constant passive defense, of course.
Offense tactics:
Solo - I like to lead off with proton volley, hit them with xray as they close in, then pop them with cosmic burst when they get to melee. At this point they are disoriented and prime target for another proton volley. If either proton volley or cosmic burst are not up, I alternate neutrino bolt/ xray beam for solid sustained damage. Against multiple targets, I use force bolt and cosmic burst to keep myself free to use proton volley, and when fighting 2 or more enemies in range, I will fire off irradiate as a very fast attack when it's up to help whittle away at the other enemies.
Group - You have to stay in pretty close range to maximize dispersion bubble coverage and keep everyone under leadership effects, so cosmic burst and irradiate are usually solid attack choices. Proton volley usually is too slow, so if cosmic burst and irradiate aren't up, I'll use the nb/xray combo to pick off damaged targets. If the group we're fighting is very difficult, I will focus my attacks on enemies with high defense, or that other teammates are attacking, so I can give the def debuff where it's most useful.
Conclusion
With the wealth of good information out there already, there probably is some duplication in this guide of other posts, but I tried to make this a more specific post with more references to my personal preferences and experiences as a FF/rad defender. Please feel free to make constructive comments or suggestions.
There are a lot of force field guides out there at this point, and I don't feel that I have anything to add to that general base of knowledge, but there were some initial complaints about my first ff/rad guide that discussed FF from a /rad secondary perspective, rather than going into detail on the rad power set. I've decided that, while another general FF guide is unnecessary at this point, a more specific FF/rad guide+build may still be of benefit to someone.
The last guide was a bit long and detailed, so I'm going to keep this straightforward. First I will describe the build and playstyle, secondly I will briefly discuss each power and why I did or didn't select it, and third I will post the build itself. At the very end, I will present a couple of specific tactics to use with this build.
FF/rad - hybrid defender
Force Field
Force field is a power set that has swung back and forth on the effectiveness scale, but the "feel" of the set has undergone relatively few changes over the past 2 years. The easiest and most commonly appreciated aspect is its defense bonus. Through two fast recharging long duration clicks and one wide radius toggle, we can single-handedly cause the majority of attacks against our team to miss, and also protect them against most status effects (which generally miss anyway). The degree to which we succeed at this roll has changed from time to time, but basically it is a fairly passive role. Keep the bubbles up, try to keep people without mez protection in your big bubble, and basically do what you want besides that.
The second aspect of FF is its soft control through knockback, positioning, and phase shift. We have a single target kb, a target aoe kb, a pbaoe pulsing kb. We also have a large aoe repel, and a single target (enemy) phase shift. This requires a more active role in combat, positioning, luck, and frequently an experienced team. These powers also tend to draw agro from a very large number of attackers, against whom we are ill suited to protect ourself without depriving our team of a portion of their defense and taking away our ability to do very much.
As a player, I - 1. Enjoy solo play, 2. Don't have a regular team, and 3. Frequently join PUGs with people who may or may not be ignorant of how to support a soft control FFer. Because of these things, I found that I was able to get the most mileage and enjoyment out of my character by largely disregarding the soft control element of the set. I chose to focus on the powers that were both constantly useful and did not interfere with me blowing stuff up. Niche powers generally got the axe, with a couple exceptions (force bolt and detention field.)
Radiation Blast
As far as rad blast is concerned, I focused primarily on single target powers. The reason for this is two-fold. First, the endurance efficiency on the aoe attacks is very poor, and when coupled with defender level damage is a very tiring way to tackle solo spawns. Secondly, the recharge is somewhat prohibitive, especially since hasten is mostly unnecessary as a FFer. Keep in mind that this approach may not be applicable to all play styles. A character who does not solo may find neutron bomb to do more total damage than x-ray beam, or may not frequently use proton volley, but as someone who likes to do a bit of everything, I found that the extra damage I brought to a team with neutron bomb or electron haze wasn't not significant enough to compensate for the inconvenience of using them to do solo missions.
Bringing It Together
This build will not be fantastic at anything. It is sort of a jack of all trades, master of none approach. Force field enables this build by allowing us to protect a team quite well with very minimal time and endurance cost, but on the other hand, it also doesn't contribute very much offensively. There is a certain balance to this, however, as other defender power sets are not nearly as forgiving. A rad emission who loses track of his toggles by spending too much time blasting becomes much less able to defend the team. Storm, kinetics, TA all rely very heavily on click powers, requiring constant attention, and frequently interrupting attack chains and draining endurance. These are broad generalizations, of course, but the point is that while FF doesn't provide any offensive bonus, it lets you protect the team with less time and endurance expenditure than any other defender set.
Because of this freedom to attack, I feel it is a waste to play a FF who neglects their offensive set. This build is heavy on attacks. It is designed to offer the team as much benefit as possible while still firing off a constant stream of damage and defense debuffs (enabling your teammates to hit more often as well.) Solo, it plays like slow blaster with good defense, mez protection, high accuracy, and a near guaranteed get out of jail free card. On a team, you give everyone defense and reduce enemy defense (and later through leadership give more defense and accuracy.) You may not be fully appreciated, as players will still miss, and enemies will still hit them from time to time, but you are a solid group facilitator, and do not require any particular group tactics or intelligence to apply the majority of your bonuses.
Lastly, as a force fielder, I have this vague notion that I should be able to have fun in PvP. Unfortuantely, the powers that are notorious in pvp (primarily the last 3 in the set) are really not very useful to my playstyle outside pvp, so my compromise was taking force bubble at 49, for when the level 50 pvp zone comes out. This build is not really prepared for level 38 pvp, though it does have tactics, force bolt, and a decently slotted personal force field. If you want to spend the majority of your time in pvp, however, I would reccomend a build more suited to the task.
Powers
Note: Due to the wide variety of character builders out there, and discrepancies between stated numbers for powers from different sources, I will not be including power numerical values. Check out some character builders and decide which one you prefer to use. Since I am providing a build, I will also not be "rating" the powers for this guide, or reccomending specific slottings for all powers.
Force Field Powers
Personal Force Field
Offers fantastic personal protection at the expense of being able to do anything else. Will not drop your toggles, but prevents you from using any powers on targets besides yourself, and prevents your toggles from affecting anyone but you. You can use aid self while in the bubble, but using the "rest" power will turn off pff. Useful for travelling safety, avoiding team wipes, absorbing an alpha strike, hiding out after you nuke, and generally staying alive when most defenders have to run. Activation time is a little slow, so it never hurts to fire it off a hair before you are actually in mortal danger. Doesn't ordinarily need more than 1 defense enhancement, unless you plan on using it in pvp.
Deflection Shield
A staple of team defense. Useless solo, but gives significant protection to the target against melee and smashing/lethal for 4 minutes. Recharges fast enough that you don't need any enhancements besides defense.
Force Bolt
Solid soloing power. Sufficient to knock over 1 enemy, including most bosses. I don't know if KB has a magnitude the same as other powers, but I find that there are some enemies that can be knocked over by other powers (like telekinetic blast) which seem to resist force bolt knockback. Aside from what appears to be a somewhat reduced "magnitude" of knockback, this thing is great. Needs at least 1 recharge to be able to keep a single enemy constantly on their butt. Accuracy is pretty good to start with, but this is a power you never want to miss, so another one never hurts, and if you use FB/snipe against bosses, the sheer quantity of FBs you use usually warrants an end rdx, in my experience. Can knock off toggles in pvp, which is nice.
Insulation Shield
Same as deflection shield, but for ranged and non smashing/lethal damage.
Detention Field
Not the most exciting power in the world, this puts one enemy into a detention field for about 30 seconds. Actual game effect: single target phase shift and immobilize. Immob resistant enemies will still be able to move, but not attack. The drawback here is that the target is immune to all other powers while phase shifted. Teams tend not to like this power a whole lot, but in groups of 1-3 players, it can be invaluable. Useful for tackling any spawn that has an undesirable enemy - sappers, nemesis LTs, an extra boss, a paragon protector who went MOG on you (jerks.) Solo, detention + force bolt can allow you to basically face only 1 enemy at a time out of a 3 mob spawn.
Dispersion Bubble
Area effect toggle centered on you with decent defense bonus and protection against hold, immobilize, and disorient. This is really a great power that you probably will run every minute you are in the game (save for when you've been put to sleep grrrr.) Probably you will want to slot it with 1 and maybe eventually 2 end rdx, and 3 defense.
Repulsion Field
Area knockback away from you. Not as expensive as it once was, but it still isn't very useful unless you're trying to pin enemies against a wall with it. Solo, it's not necessary if you have force bolt, and in a group it is difficult to get pick up groups to coordinate with this power. I tried it for awhile instead of force bolt, but when you're holding 1 enemy in the field constantly, you do lose endurance quickly. Decent in pvp as it can deter stalkers and drop toggles, but also will drain your end like no tomorrow if you're at melee with someone who's knockback resistant.
Repulsion Bomb
Area knockback targetted at an enemy. Despite targetting an enemy, the knockback is away from you, which means flying above enemies allows you to sort of knock enemies down, which is slightly less offensive to a team. This power has a small chance of a low magnitude disorient, which I used to reccomend you stack with cosmic burst to stun bosses. It's not really reliable for that purpose any more, thanks to the low chance, and the long recharge. I've also tried to use this power as a supplement to force bolt, or an area effect force bolt, but the long activation time and greatly increased recharge time basically means that this is an agro magnet. Great for dropping toggles in pvp, and occasionally useful for knocking down a few enemies every 30 or 40 seconds in a team, but I just can't reccomend it any more.
Force Bubble
Huge area repel away from you. Occasionally knocks down enemies in the radius of effect (like 5% chance, very small.) Similar to repulsion field in that it is unnecessary solo, and very difficult to effectively apply in a team setting. Occasionally you will be able to put it to use against large groups of enemies with poor ranged attacks, but generally you have better ways of defending a team. One option is to flick it on, then off, and go into personal force field, to take some heat off the rest of your team. You also can use it to zip around a room, agro everything, then hide behind a wall and go into pff. I mostly use this to pull a group together prior to nuking. Decent scrapper deterrant (anyone without repel deterrant really, in pvp.)
Radiation Blast Powers
Neutrino Bolt
Low damage, fast activation, fast recharge power. Decent dps alone, "ok" contribution to attack chain. Occasionally proclaimed to be good enough that you don't really need other attack powers to make a good attack chain, but some number crunching will show that that's not really the case. It is true that you can survive without other attack powers, but as a soloist, I like to have more than JUST this in my single target arsenal. Anyway, you have no choice to take it or not, so slot it up and it's not bad.
X-ray Beam
Not a bad power. Single target with slightly better damage and slightly longer recharge than neutrino bolt. Comparable to power bolt, charged bolts, and most other moderate damage low level blasts. Works well to fill the gap between neutrino bolt for a decent increase in damage output early on, plus it shoots green lasers out of your eyes, which is pretty cool.
Irradiate
Area effect damage over time attack centered on yourself. Total damage equals that of x-ray beam, approximately, and endurance cost is slightly less than 4x as much. That means this starts to be an efficient attack with 4 targets, and it also applies a very hefty defense debuff for about 30 seconds! Overall a good power, but it can be draining to use solo. Super fast activation time though, so a decent precursor to a nuke, and easily able to be used to zoom in, debuff a group of enemies your team is fighting, and zoom out.
Electron Haze
Highest damage power so far in the set, basically made a pain thanks to its narrow cone, inconsistent knockback, high cost, and lame activation time. In the right hands, this power can still do some good damage, and starts to be efficient around 2-3 targets, but as far as dps goes, it isn't really that great. Against a single target, you can fire off nb and xray for the same activation time of 1 EH, doing almost 20% more damage and spending half the endurance. If you are consistently fighting larger groups, it becomes worthwhile, but I always seemed to have better powers to use.
Proton Volley
Our snipe. Not bad as far as snipes go. Doesn't usually hit the enemy until the animation is done, so you can usually duck out of sight by moving right before the firing animation begins and avoid getting more than 1 enemy. Looks kind of amusing. The defense debuff works well with a snipe, because it makes following up after the snipe pretty easy. It has a very long activation, but recharges faster than electron haze. I kind of think of it applying a little more than 2x electron haze damage for approximately 2x the activation time, but costing the same and recharging faster. So I picked proton volley over EH, since I prefer finishing off single targets quickly as opposed to having to face the full amount of enemy damage until eventually killing them all at once. Dispersion bubble, force bolt, and cosmic burst regularly allow me to use PV in normal combat settings without being interrupted.
Aim
Really a must have for an offensive defender. Useful in two ways. First, it's up pretty often, and is a solid improvement to overall damage and accuracy. Secondly, it gives us a "must hit" guarantee on certain powers. Don't bother slotting accuracies in your nuke, because aim will always come first. When you need to apply that defence debuff with irradiate on critical enemies, aim will be up. Needs a couple recharges usually, but hit buff is not necessary.
Cosmic Burst
Finally a real combat power. Better damage than anything so far, plus a nice mag3 disorient. Range is short, but that's not usually a problem. This is simultaneously the third prong of your defense, and the lynchpin of your attack chain. More details in the tactics section.
Neutron Bomb
Area effect damage targetted on the enemy. Kind of a disappointment. It's like m30 grenade, minus knockback, with higher end cost, 29 circle later than an AR blaster would get it (and I never found m30 to be that useful to begin with.) Pros: looks cool, can hit a group of enemies from far away, cheaper than irradiate. Cons: Sad damage (less than irradiate or x-ray), harder to position where you want than irradiate, slow activation. I would only reccomend this for a "group only" character.
Atomic Blast
Arguably one of the better nukes in the game, and the one to truly deserve the name "nuke" heh. Atomic blast is very solid damage with a nice mag 3 hold on top. It does no knockback, which means even if you don't kill everyone, you haven't moved anyone out of place for futher aoe follow up from your teammates, and the hold helps keep you from getting pilllaged by survivors.
Power Mastery Powers
I chose Power Mastery because it seems to best complement my playstyle, so I have included the powers from that ancillary set only.
Conserve Power
Reduces your endurance cost by half for a little while. Long recharge. Unless you go all out AoE, this is pretty unnecessary. FF drains very little end, and single target rad blast is pretty managable as well.
Power Build Up
Look Ma! I'm a real blaster! Gives you a boost similar to build up, and also double the duration of your secondary effects for about 10 seconds. Works well prior to aim (since it buffs aim) and then before either irradiate (for the defense debuff) or atomic blast (for damage and the hold duration). PBU + aim + atomic blast can drop yellows and oranges pretty frequently. Also works well before cosmic burst if you're fighting a boss. You can usually get off 2 bursts before PBU wears off, which should keep the boss disoriented for a nice duration.
Temporary Invulnerability
Reduces smashing and lethal while the toggle is up. Worthwhile, but not exceptional. Helps to take the edge off, but hardly a license to tank. I chose it so I can get total focus.
Total Focus
Well, you may only have 3 circles left to 50, but you finally got another good single target power. Works great with cosmic burst to disorient multiple opponents in a row. Long activation and recharge, but a solid choice all around.
The Build
Exported from version 1.5C of CoH Planner
http://joechott.com/coh
Archetype: Defender
Primary Powers - Ranged : Force Field
Secondary Powers - Support : Radiation Blast
01 : Neutrino Bolt acc(01) dam(5) dam(5) dam(11) recred(15) endred(34)
01 : Deflection Shield defbuf(01) defbuf(3) defbuf(3) endred(43)
02 : X-Ray Beam acc(02) dam(9) dam(9) dam(11) recred(21) endred(34)
04 : Personal Force Field defbuf(04) recred(40) defbuf(42)
06 : Insulation Shield defbuf(06) defbuf(7) defbuf(7) endred(46)
08 : Force Bolt recred(08) acc(34) recred(37) endred(42)
10 : Hover endred(10)
12 : Dispersion Bubble endred(12) defbuf(13) defbuf(13) defbuf(15) endred(33)
14 : Fly fltspd(14) fltspd(36) fltspd(37) endred(46)
16 : Proton Volley acc(16) dam(17) dam(17) dam(19) recred(19) endred(21)
18 : Swift runspd(18)
20 : Health hel(20) hel(46)
22 : Stamina endrec(22) endrec(23) endrec(23)
24 : Irradiate acc(24) dam(25) dam(25) dam(27) endred(27) recred(33)
26 : Aim recred(26) recred(40)
28 : Cosmic Burst acc(28) dam(29) dam(29) dam(31) recred(31) recred(31)
30 : Detention Field recred(30) acc(36) recred(37)
32 : Maneuvers defbuf(32) endred(33) defbuf(43) defbuf(43)
35 : Tactics thtbuf(35) endred(36)
38 : Atomic Blast dam(38) dam(39) dam(39) recred(39) recred(40)
41 : Power Buildup recred(41) recred(42)
44 : Temp Invulnerability damres(44) damres(45) damres(45) endred(45)
47 : Total Focus acc(47) dam(48) dam(48) dam(48) recred(50) recred(50)
49 : Force Bubble endred(49) endred(50)
-------------------------------------------
01 : Brawl Empty(01)
01 : Sprint Empty(01)
02 : Rest Empty(02)
Explanation of some slotting decisions:
Most attacks were slotted acc/3dam/end/rech. This can be adjusted as needed, depend on how you use your attack chains, and how much end you find that you use. Cosmic burst got 2rech and no end, since the damage output is so good, and stacking disorients is very useful. A daring player could drop accs from all powers, put more tohit into tactics, and rely on the def debuff from rad to improve their accuracy, but I slot 1 accuracy.
Force bolt, and both individual shields got an end rdx to compensate for running leadership toggles and TI all the time, but depending on what toggles you use, they may be unnecessary.
I didn't slot more tohit in tactics because radiation blast is usually not missing after my first hit anyway. I have aim for when I NEED to hit, and 1acc in all powers anyway, so I decided I didn't need more in tactics. YMMV
Detention field needs 2 recharges to have ready by the time it wears off, and forcebolt takes 2 to comfortably have ready whenever I want it. I put an accuracy in both because they both are powers that can cause a lot of pain if you need them and miss.
Lastly, these are endgame slottings. Your slotting with TOs or DOs should not be the same as this, and some powers may be slotted in a slightly different order than presented.
Tactics
I'll keep this brief.
Defense tactics:
Keep your team bubbled all the time. It's really the best you have to offer, and if you let it slip, you risk things falling apart with no way to "recover." Try to keep the dispersion bubble around controllers, defenders, and blasters, and generally run leadership toggles most of the time. In a team, reserve force bolt and detention field for emergencies, or enemies that are not part of the melee fray. Solo I like to use detention field on bosses while I clean up the minions around them, though generally I don't use it on EVERY group. Generally I use cosmic burst as my primary defense, force bolt as secondary, and detention field as last ditch. Dispersion bubble is my constant passive defense, of course.
Offense tactics:
Solo - I like to lead off with proton volley, hit them with xray as they close in, then pop them with cosmic burst when they get to melee. At this point they are disoriented and prime target for another proton volley. If either proton volley or cosmic burst are not up, I alternate neutrino bolt/ xray beam for solid sustained damage. Against multiple targets, I use force bolt and cosmic burst to keep myself free to use proton volley, and when fighting 2 or more enemies in range, I will fire off irradiate as a very fast attack when it's up to help whittle away at the other enemies.
Group - You have to stay in pretty close range to maximize dispersion bubble coverage and keep everyone under leadership effects, so cosmic burst and irradiate are usually solid attack choices. Proton volley usually is too slow, so if cosmic burst and irradiate aren't up, I'll use the nb/xray combo to pick off damaged targets. If the group we're fighting is very difficult, I will focus my attacks on enemies with high defense, or that other teammates are attacking, so I can give the def debuff where it's most useful.
Conclusion
With the wealth of good information out there already, there probably is some duplication in this guide of other posts, but I tried to make this a more specific post with more references to my personal preferences and experiences as a FF/rad defender. Please feel free to make constructive comments or suggestions.