Question: Cathode rays were first named by which German physicist?

full_context: Document 1: Eugen Goldstein: Eugen Goldstein (5 September 1850 – 25 December 1930) was a German physicist. He was an early investigator of discharge tubes, the discoverer of anode rays, and is sometimes credited with the discovery of the proton.
Document 2: Cathode ray: Cathode rays (also called an electron beam or e-beam) are streams of electrons observed in vacuum tubes. If an evacuated glass tube is equipped with two electrodes and a voltage is applied, the glass behind of the positive electrode is observed to glow, due to electrons emitted from and traveling away from the cathode (the electrode connected to the negative terminal of the voltage supply). They were first observed in 1869 by German physicist Johann Wilhelm Hittorf, and were named in 1876 by Eugen Goldstein "Kathodenstrahlen", or cathode rays.
Document 3: Crookes tube: A Crookes tube (also Crookes–Hittorf tube) is an early experimental electrical discharge tube, with partial vacuum, invented by English physicist William Crookes and others around 1869-1875, in which cathode rays, streams of electrons, were discovered.
Document 4: Arnold Sommerfeld: Arnold Johannes Wilhelm Sommerfeld, {'1': ", '2': ", '3': 'ForMemRS', '4': "} (] ; 5 December 1868 – 26 April 1951) was a German theoretical physicist who pioneered developments in atomic and quantum physics, and also educated and mentored a large number of students for the new era of theoretical physics. He served as PhD supervisor for many Nobel Prize winners in physics and chemistry (only J. J. Thomson's record of mentorship is comparable to his).
Document 5: Cherenkov radiation: Cherenkov radiation, also known as Vavilov–Cherenkov radiation (named after Sergey Vavilov and Pavel Cherenkov), is electromagnetic radiation emitted when a charged particle (such as an electron) passes through a dielectric medium at a speed greater than the phase velocity of light in that medium. The characteristic blue glow of an underwater nuclear reactor is due to Cherenkov radiation. It is named after Soviet scientist Pavel Alekseyevich Cherenkov, the 1958 Nobel Prize winner who was the first to detect it experimentally. A theory of this effect was later developed within the framework of Einstein's special relativity theory by Igor Tamm and Ilya Frank, who also shared the Nobel Prize. Cherenkov radiation had been theoretically predicted by the English polymath Oliver Heaviside in papers published in 1888–89.
Document 6: Julius Plücker: Julius Plücker (16 June 1801 – 22 May 1868) was a German mathematician and physicist. He made fundamental contributions to the field of analytical geometry and was a pioneer in the investigations of cathode rays that led eventually to the discovery of the electron. He also vastly extended the study of Lamé curves.
Document 7: Electron: Electrons play an essential role in numerous physical phenomena, such as electricity, magnetism, chemistry and thermal conductivity, and they also participate in gravitational, electromagnetic and weak interactions. Since an electron has charge, it has a surrounding electric field, and if that electron is moving relative to an observer it will generate a magnetic field. Electromagnetic fields produced from other sources (not those self-produced) will affect the motion of an electron according to the Lorentz force law. Electrons radiate or absorb energy in the form of photons when they are accelerated. Laboratory instruments are capable of trapping individual electrons as well as electron plasma by the use of electromagnetic fields. Special telescopes can detect electron plasma in outer space. Electrons are involved in many applications such as electronics, welding, cathode ray tubes, electron microscopes, radiation therapy, lasers, gaseous ionization detectors and particle accelerators.
Document 8: Emilio Segrè: Emilio Gino Segrè (1 February 1905 – 22 April 1989) was an Italian physicist and Nobel laureate who discovered the elements technetium and astatine, and the antiproton, a sub-atomic antiparticle, for which he was awarded the Nobel Prize in Physics in 1959.
Document 9: Max Planck: Max Karl Ernst Ludwig Planck, FRS ( ; 23 April 1858 – 4 October 1947) was a German theoretical physicist whose discovery of energy quanta won him the Nobel Prize in Physics in 1918.
Document 10: History of mass spectrometry: The history of mass spectrometry has its roots in physical and chemical studies regarding the nature of matter. The study of gas discharges in the mid 19th century led to the discovery of anode and cathode rays, which turned out to be positive ions and electrons. Improved capabilities in the separation of these positive ions enabled the discovery of stable isotopes of the elements. The first such discovery was with the element neon, which was shown by mass spectrometry to have at least two stable isotopes: Ne (neon with 10 protons and 10 neutrons) and Ne (neon with 10 protons and 12 neutrons). Mass spectrometers were used in the Manhattan Project for the separation of isotopes of uranium necessary to create the atomic bomb.
Document 11: Grenz rays: Grenz rays are part of the electromagnetic spectrum comprising low energy (ultrasoft) X-rays. These were first investigated by Gustav Bucky in 1923 using a cathode vacuum tube with a lithium borate glass window, which he labeled Grenz rays as he believed that the biological effects resembled those of UV light and traditional X-rays and hence were on the border between the two ("Grenz" = border in German). These rays are also known as Bucky rays.
Document 12: Cockcroft–Walton generator: The Cockcroft–Walton (CW) generator, or multiplier, is an electric circuit that generates a high DC voltage from a low-voltage AC or pulsing DC input. It was named after the British and Irish physicists John Douglas Cockcroft and Ernest Thomas Sinton Walton, who in 1932 used this circuit design to power their particle accelerator, performing the first artificial nuclear disintegration in history. They used this voltage multiplier cascade for most of their research, which in 1951 won them the Nobel Prize in Physics for "Transmutation of atomic nuclei by artificially accelerated atomic particles". Less well known is the fact that the circuit was discovered much earlier, in 1919, by Heinrich Greinacher, a Swiss physicist. For this reason, this doubler cascade is sometimes also referred to as the Greinacher multiplier. Cockcroft–Walton circuits are still used in particle accelerators. They also are used in everyday electronic devices that require high voltages, such as X-ray machines, television sets, microwave ovens and photocopiers.
Document 13: Georg Christoph Lichtenberg: Georg Christoph Lichtenberg (1 July 1742 – 24 February 1799) was a German scientist, satirist, and Anglophile. As a scientist, he was the first to hold a professorship explicitly dedicated to experimental physics in Germany. Today, he is remembered for his posthumously published notebooks, which he himself called "Sudelbücher", a description modelled on the English bookkeeping term "scrapbooks", and for his discovery of the strange tree-like electrical discharge patterns now called Lichtenberg figures.
Document 14: Philipp Lenard: Philipp Eduard Anton von Lenard (7 June 1862 – 20 May 1947) was a German physicist and the winner of the Nobel Prize for Physics in 1905 for his research on cathode rays and the discovery of many of their properties. He was a nationalist and anti-Semite; as an active proponent of the Nazi ideology, he had supported Adolf Hitler in the 1920s and was an important role model for the "Deutsche Physik" movement during the Nazi period. Notably, he had labeled Albert Einstein's contributions to science as constituting "Jewish physics".
Document 15: Wehnelt cylinder: A Wehnelt cylinder (also known as "Wehnelt cap", "grid cap" or simply "Wehnelt") is an electrode in the electron gun assembly of some thermionic devices, used for focusing and control of the electron beam. It is named after Arthur Rudolph Berthold Wehnelt, a German physicist, who invented it during the years 1902 and 1903. Wehnelt cylinders are found in the electron guns of cathode ray tubes and electron microscopes, and in other applications where a thin, well-focused electron beam is required.
ground_truth: Eugen Goldstein