How to Measure the Speed of Synchrotron Radiation

The dependence or independence of the speed of light on the source velocity is of fundamental importance for fundamental physics. The independence of the speed of light lies at the heart of the special theory of relativity and modern electrodynamics. Maxwell’s equations of electrodynamics, which are invariant under the Lorentz transformations in any inertial system, show that the speed of light does not vary with the light source velocity. This conclusion affects many sections of physics -rom optics to astrophysics.

At the same time, Maxwell's theory seems to anchor the ideological approach of the ether in the form of electromagnetic fields, the perturbation of which generates the propagation of electromagnetic waves. But the ether theory was refuted by the experiments of Michelson and Morley. Therefore, in our opinion, an electrodynamics should be developed sooner or later that is adequate to the realm surrounding us and explains all optical phenomena and, in particular, the nature of a photon, over which many prominent scientists (including academician O.N. Krokhin) still rack their brains.
In the light of what has been said, it is extremely important for us to carry out a control experiment that will unequivocally testify whether the synchrotron radiation velocity V SR obtained using the Sibiria-1 storage ring or its counterpart is equal to 2c or c. The schematic of the experiment is shown in Fig. 1. The distances are given in meters.
The red arrow indicates the path of the electrons, which produce synchrotron radiation (SR) in each curved section. At point of emission (14), the SR is launched into the rectilinear SR output channel and measured with an optical detector (12). The information about the experiment and the source of synchrotron radiation --the Sibira-1 electron storage ring can be found in detail elsewhere [1,2].
To determine the speed of synchrotron radiation in the rectilinear segment of the output channel (7), use is made of the following measurement scheme (Fig. 2).

Figure2. Proposed schematic of the measurements: (1) radiation output channel;
(2) output window; (3) radiation detector of the measuring channel; (4) detector of the reference channel; (5) reference radiation output channel; (6) mirror of the reference channel output; (7) point of emission of an electron from a stationary orbit; (8) twobeam oscilloscope; (9) reference channel cable; (10) measuring channel cable. (3) and (4) must be pre-synchronized by changing the length of cables (9) and (10). To this end, the detectors are placed side by side and irradiated with a repetitively pulsed laser light, which makes it possible to synchronize signals in the measuring and reference channels of the oscilloscope. The measuring base L must satisfy the condition L = (2n + 1) × T × 30 cm, where n = 0, 1, 2, 3, ...; and T is the period of rotation of electrons along a circular orbit in the synchrotron (in ns).

Radiation detectors
When this condition is met, one of the following oscillograms will be observed on the oscilloscope screen (Fig. 3).

Figure3. Oscillograms observed on the oscilloscope screen at a synchrotron radiation speed of light equal to (a) c and (b) 2c.
On the given oscillograms channel No. 1 registers a signal from the synchrotron radiation that has passed through the segment L. Channel No. 2 serves as a reference channel recording the moments of light emission at point (7). For a qualitative picture, i.e. the answer to the question whether the speed of light is equal to c or 2c, the segment from point (7) through mirror (6) to detector window (4) can be neglected as compared to the distance L (as shown in Fig. 3). If it is necessary to accurately measure the speed of light of synchrotron radiation, then this segment should be taken into account.
For the Sibiria-1 electron storage ring, the minimum value of the segment, calculated from the above formula, is L = 869 cm. Therefore, for a real length L ~ 720 cm, the shape of the oscillograms in Fig. 3 for the two cases will slightly change. But all the same, one can immediately say that the speed is either c or 2c.
If for technical reasons it is difficult to make use of the reference channel near point (14) in Fig. 1, then it is possible to use a glass plate input/output system and measure the distance L from this place.