D O C U M E N T 1 9 3 J U L Y 1 9 2 1 1 3 3

rays deflected at certain s have a uniform velocity and how the energy loss is

dependent on the original velocity, the deflection angle, and the ordinal number.

Besides Geiger, Wagner in Munich could probably also be considered for such

experiments.[5]

Now perhaps I may say something else about the problem, or more correctly, ask

something. If the generated X-rays are defined by the equation

, ought then to be larger, the larger is ; i.e.,

the larger the loss in velocity. Shouldn’t one then expect that be larger, the larger

the deflection s are? That is, that the energy distribution curve of “brems” X-rays

at larger azimuths would have their maxima shifted toward smaller wavelengths?

But Wagner has found precisely the opposite in his

experiments,[6]

namely, that at

150° the maximum of the bremsstrahlung lies at higher wavelengths than at 90°. Or

else, does this have nothing to do with it because, if one doesn’t calculate classi-

cally, one cannot say anything about the correlation between the orientations of the

deflected cathode rays and the generated X-rays? Additionally, in these cases we

have thick layers again, of course, and therefore summation effects.

Now I beg your forgiveness again for my tardy reply.

I hope you are having a very relaxing time in the countryside and

am,[7]

with best

regards, yours very sincerely,

Lise Meitner.

193. To Lise Meitner

Wustrow, 27 July

[1921][1]

Dear Miss Meitner,

Cordial thanks for your kind

information.[2]

I think one should use cathode rays

at high tension, which one generates electrostatically by perhaps using an auto-

matic tension regulator. I have an idea for one. One can certainly obtain

105

volts,

perhaps even more. It must be difficult to get a sufficiently thin diaphragm. If this

is impossible, gas between two diaphragms would have to be used and constantly

H L

1

L

2

– = L

1

L

2

–