12
R. Rüffer and A. I. Chumakov
1.2 Historical Development
In this chapter we want—on the example of NRS with SR—to point out how research
may evolve from first ideas and discussions to the hopefully successful finish. What
are the scientific dreams, at the beginning and at the end of such an endeavour?
What are the technical challenges? Are there other aspects, which were crucial for
the development and the science of such a project? Eventually, we can report on
the successful achievement of this endeavour: Nuclear Resonance Scattering with
Synchrotron Radiation.
Even when there were already some discussions going on, the “kick-off” moment
for nuclear resonance with synchrotron radiation was certainly the Mössbauer conference 1974 in Bendor (France). In his contribution Stan Ruby discussed synchrotron radiation as a new source for Mössbauer spectroscopy instead of radioactive
sources [26]. It was at a time when SR was mainly a nuisance for the researchers
doing high-energy physics with the new colliders using highly energetic electrons
and positrons. This unavoidable SR prevented them to increase the particle energy
to higher and higher values. Anyway, first attempts had already started to use that
radiation in a parasitic manner e.g. for atomic and solid state physics. Now, also the
Mössbauer community started with several groups all over the world trying to excite
Mössbauer isotopes with SR.
1.2.1 Scientific Dreams
Of course the idea itself—creating a resonant Mössbauer beam out of the SR—is
highly appealing and warrants to be tackled. That was for sure one of the important
reasons to start the endeavour. On the other hand the discussions at that time show that
the combination of the outstanding features of both, the SR and the MB effect, would
make new experiments feasible either out of reach or deemed extremely difficult.
Diffraction experiments were named very early with emphasis on the “phase
problem” [27]. The temporal coherence of the new source and superradiance has
been mentioned as well [28]. In the course of the preparation for a dedicated SR
source in Europe, a first set of experiments has been proposed [29]:
• Analysis of the magnetic structure of complicated compounds which would
benefit from the defined polarization of the SR.
• Time experiments such as the observation of relaxation processes between hyperfine levels, the time dependence of the Debye-Waller factor, and the interference
between the Mössbauer effect and the conversion or other competing processes.
Even laser activation of the environment of the MB nuclei synchronous to the SR
flash, nowadays known as pump-and-probe, has been proposed.
• Nuclear γ -optics which includes dichroism, magnetooptic effects such as double
refraction and Faraday rotation. Further, the interference of the nuclear and the
R. Rüffer and A. I. Chumakov
1.2 Historical Development
In this chapter we want—on the example of NRS with SR—to point out how research
may evolve from first ideas and discussions to the hopefully successful finish. What
are the scientific dreams, at the beginning and at the end of such an endeavour?
What are the technical challenges? Are there other aspects, which were crucial for
the development and the science of such a project? Eventually, we can report on
the successful achievement of this endeavour: Nuclear Resonance Scattering with
Synchrotron Radiation.
Even when there were already some discussions going on, the “kick-off” moment
for nuclear resonance with synchrotron radiation was certainly the Mössbauer conference 1974 in Bendor (France). In his contribution Stan Ruby discussed synchrotron radiation as a new source for Mössbauer spectroscopy instead of radioactive
sources [26]. It was at a time when SR was mainly a nuisance for the researchers
doing high-energy physics with the new colliders using highly energetic electrons
and positrons. This unavoidable SR prevented them to increase the particle energy
to higher and higher values. Anyway, first attempts had already started to use that
radiation in a parasitic manner e.g. for atomic and solid state physics. Now, also the
Mössbauer community started with several groups all over the world trying to excite
Mössbauer isotopes with SR.
1.2.1 Scientific Dreams
Of course the idea itself—creating a resonant Mössbauer beam out of the SR—is
highly appealing and warrants to be tackled. That was for sure one of the important
reasons to start the endeavour. On the other hand the discussions at that time show that
the combination of the outstanding features of both, the SR and the MB effect, would
make new experiments feasible either out of reach or deemed extremely difficult.
Diffraction experiments were named very early with emphasis on the “phase
problem” [27]. The temporal coherence of the new source and superradiance has
been mentioned as well [28]. In the course of the preparation for a dedicated SR
source in Europe, a first set of experiments has been proposed [29]:
• Analysis of the magnetic structure of complicated compounds which would
benefit from the defined polarization of the SR.
• Time experiments such as the observation of relaxation processes between hyperfine levels, the time dependence of the Debye-Waller factor, and the interference
between the Mössbauer effect and the conversion or other competing processes.
Even laser activation of the environment of the MB nuclei synchronous to the SR
flash, nowadays known as pump-and-probe, has been proposed.
• Nuclear γ -optics which includes dichroism, magnetooptic effects such as double
refraction and Faraday rotation. Further, the interference of the nuclear and the