# Is there something missing in this sentence?

In John Gribbin's Ten Tantalizing Truths, the author discusses the cyclotron:-

for a particular mass as the particles spiral outward, the rotation frequency stays constant, because the particles are traveling faster over a longer distance, round a bigger circle. So the frequency of the kick provided by the electric field stays the same and the beam continues to accelerate. But this sets a limit on how fast the particles can go. Once they are going at a sizeable fraction of the speed of light, the extra energy they receive from each kick by the electric field doesn’t simply go into making them move faster; it makes them more massive. But the cyclotron frequency depends on the mass, so they get out of step with the varying electric field. This is unfortunate because the extra mass is a measure of how much more energy they are carrying, so even if the speed doesn’t increase by much, they pack a more powerful punch when they hit the target, which is what the experimenters want.

How can it be "unfortunate" while this is what the experimenters want? Is there something missing in this sentence, like "however" for example? Or can "unfortunate" have another meaning here?

• This question also appears on Physics SE. Commented Jul 17, 2023 at 13:22