| Paper |
Title |
Page |
| CT05 |
Beam Loss Detection at Radiation Source ELBE
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65 |
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- P. Michel, J. Teichert, R. Schurig, H. Langenhagen
FZR, Forschungszentrum Rossendorf, Dresden, Germany
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The Rossendorf superconducting Electron Linac of high Brilliance and low
Emittance (ELBE) delivers an 40 MeV, 1 mA cw-beam for different
applications such as bremsstrahlung production, electron channelling,
free-electron lasers or secondary particle beam generation. In this
energy region in case of collisions of the electron beam with the pipe
nearly all beam power will be deposited into the pipe material. Therefore
a reliable beam loss monitoring is essential for machine protection
at ELBE. Different systems basing on photo multipliers, compton diodes
and long ionization chambers were studied. The pros and cons of the
different systems will be discussed. Ionization chambers based on
air-isolated RF cables installed some cm away parallel to the beam line
turned out to be the optimal solution. The beam shut-off threshold was
adjusted to 1 μC integral charge loss during a 100 ms time interval. Due
to the favourable geometry the monitor sensitivity varies less than ±50%
along the beam line (different shielding conditions).
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| PT15 |
Performance of the ELBE BPM Electronics
|
202 |
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- P. Evtushenko, R. Schurig
FZR, Forschungszentrum Rossendorf, Dresden, Germany
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The ELBE radiation source is based on a superconducting linac. Initially
it was designed to be used in CW mode with repetition rates either 13 MHz
either 260 MHz. Later it was decided to operate the accelerator with
reduced repetition rates for diagnostic reasons and for certain users.
Now it is possible to operate at repetition rate 13/n MHz, where n can be
2, 4, 8, 16, 32, 64, and 128. It is required that the BPM system supports
any of these operation modes. A core element of the BPM electronics is a
logarithmic amplifier AD8313 made by Analog Devices Inc. The logarithmic
amplifier is a direct RF to DC converter rated up to 2.5 GHz. Initial
design of the BPM electronic was sophisticated only for CW operation with
repetition rate more than 10 MHz, since bandwidth of the AD8313 is
about of 10 MHz. Additionally a sample and hold amplifier is built in to
provide enough time for an ADC to make measurements. The sample and hold
amplifier is synchronized with a micropulse frequency. In the paper we
present results of the modified BPM electronics test.
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