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One of the 10 cells of AA Injection Kicker K4
1979-08-01
The 3.5 GeV/c Antiproton Accumulator (AA) had 2 delay-line type injection kickers, K3 (12 cells) and K4 (10 cells). Here we see one of the K4 cells, with ferrite between stainless-steel plates. Pulse voltage: 61 kV; rise/fall-time 86 ns; flat-top 460 ns; top flatness +-2%. During injection, the open side of the C-shaped kickers was closed off with a fast shutter, so that their stray field would not perturb the stack of already accumulated antiprotons.
1980-02-01
The freshly injected antiprotons, while circulating on the injection orbit, were subjected to fast stochastic "precooling" for several seconds (in momentum and in the vertical plane). This precooling pickup is being readied by Gerard Laurent for installation in its tank. Precooling PUs and kickers were of identical construction (except for the kickers having cooling circuits), with C-shaped ferrites sandwiched between C-shaped metal plates and couplers at the back of the C. For reasons explained in 8002234, they were also equipped with shutters which closed the open side of the C when there was beam on the injection orbit. For more on precooling see 8020234, 8004064.
1985-01-01
The longitudinal and transverse complex impedances Z/sub l//n and Z/sub t/, respectively, have been calculated for both the SSC injection and abort kickers. The calculations assumed that no attempt was made to shield the beam from the kickers. We took the injection and abort kickers to be as specified. The injection kickers were ferrite with a single-turn design, and the abort kickers were of a ''window-frame design'' with tape wound cores.
Development of the kicker magnet for SPring-8 synchrotron
1994-12-31
Fast-pulsed kicker-magnets will be used for the SPring-8 synchrotron in the beam injection and extraction. A prototype kicker-magnet and the power supply were constructed and tested. The kicker magnet has been completed successfully, and the experimental result is reported. (author).
Design of kicker magnet and power supply unit for synchrotron beam injection
To inject beams from the positron accumulator ring (PAR) into the synchrotron, a pulsed kicker magnet is used. The specifications of this kicker magnet and the power supply unit are listed and discussed in this report.
Design of kicker magnet and power supply unit for synchrotron beam injection
1991-03-01
To inject beams from the positron accumulator ring (PAR) into the synchrotron, a pulsed kicker magnet is used. The specifications of this kicker magnet and the power supply unit are listed and discussed in this report.
1995-10-01
New injection schemes for the three kind of low emittance lattices of the photon factory was designed. A traveling wave type kicker magnet is applied to make a injection pulse bump. A model kicker magnet was also designed and constructed. The magnet is traveling wave kicker magnet and the impedance of the test magnet was designed to 6.25{Omega}. The experimental measurement of properties of the magnet will be mentioned. (author).
The kicker magnet system for TRISTAN Accumulation Ring injection
1994-12-01
The injection of electron beams to TRISTAN Accumulation Ring (AR) was started in November 1983 and the positron injection started in November 1985. For the injection of electron and positron beams to AR, the unique kicker system was developed. In the kicker power supply the charging to the main capacitor was done with the resonant charge system together with the auxiliary charging unit. The impedance matching circuit was added to the kicker magnet for getting the required current form with least reflecting oscillation. In this paper we report the performance of this kicker system. (author).
The kicker magnet system for TRISTAN Accumulation Ring injection
1994-01-01
The injection of electron beams to TRISTAN Accumulation Ring (AR) was started in November 1983 and the positron injection started in November 1985. For the injection of electron and positron beams to AR, the unique kicker system was developed. In the kicker power supply the charging to the main capacitor was done with the resonant charge system together with the auxiliary charging unit. The impedance matching circuit was added to the kicker magnet for getting the required current form with least reflecting oscillation. In this paper we report the performance of this kicker system. (author)
Development of a Fast High-Power Pulser and ILC DR Injection/Extraction Kicker
2007-10-16
Kicker is an efficient HOM power extractor. Peak HOM voltage and average power at the feeder may be sufficient to act on the kicker pulser. Feeder imperfections (real cable, feedthroughs, kicker electrodes, loads) is one source of residual energy between bunches. HOM spectrum is broad.
Following the upgrade of the LNLS injector system with the addition of a 500 MeV booster synchrotron,the storage ring in-vacuum ferrite injection kicker magnets started to show overheating due the interaction with high frequency electromagnetic fields induced by the electron beam. In this paper, we describe the design of a new ceramic chamber for the kickers which minimize this effect by decreasing the coupling impedance of the kickers and their interaction with the electron beam.
RHIC injection kicker impedance
1995-05-01
The longitudinal impedance of the RHIC injection kicker is measured using the wire method up to a frequency of 3 GHz. The mismatch between the 50 ohm cable and the wire and pipe system is calibrated using the TRL calibration algorithm. Various methods of reducing the impedance, such as coated ceramic pipe and copper strips are investigated.
Slot-type kicker for the AA stochastic cooling
1979-06-01
A "slotted transmission line" structure was used for both pickups and the kicker of one of the stochastic cooling systems of the Antiproton Accumulator (AA). They served for the cooling of the high-density stack, in momentum and in both transverse planes. In the beginning in a single band, 1-2 GHz, later in 3 bands, 1-2, 2-4 and 4-8 GHz. The kicker of the first generation, shown here, was located where the dispersion was zero and the beam size small, and thus had a quadratic cross-section. The pickups were rectangular and wider in the horizontal plane. See also 7906193
Emittance Growth at LHC Injection from SPS and LHC Kicker Ripple
Fast pulsed kicker magnets are used to extract beams from the SPS and inject them into the LHC. The kickers exhibit time-varying structure in the pulse shape which translates into small offsets with respect to the closed orbit at LHC injection. The LHC damper systems will be used to damp out the resulting betatron oscillations, to keep the growth in the transverse emittance within specification. This paper describes the results of the measurements of the kicker ripple for the two systems, both in the laboratory and with beam, and presents the simulated performance of the transverse damper in terms of beam emittance growth. The implications for LHC operation are discussed.
Beam kicker control system for CSR project in Lanzhou
2008-01-01
The beam kicker system is a key part for beam extraction and injection in ring-like accelerator, which works under high voltage and huge current. This paper introduces the kicker control system based on ARM+DSP+FPGA for CSR project in Lanzhou, which has nanosecond timing precision. ARM mainly completes the control signals with the network communication, and the time control precision for the beam kicker system is performed mainly by FPGA and DSP. The sequence control signals through the optic fiber transmission, synchronous to kicker power supply the voltage to assign uses the signal isolators and ferrites to suppress the disturbance pulses. Scene test has proved that this system can meet beam kicker control's request and work safely and stably. The control system has extracted and injected the CSR beam successfully in October 2007. (authors)
THE COUPLING IMPEDANCE OF THE RHIC INJECTION KICKER SYSTEM.
1999-06-28
IN THIS PAPER, RESULTS FROM IMPEDANCE MEASUREMENTS ON THE RHIC INJECTION KICKERS ARE REPORTED. THE KICKER IS CONFIGURED AS A ''C'' CROSS SECTION MAGNET WITH INTERLEAVED FERRITE AND HIGH-PERMITTIVITY DIELECTRIC SECTIONS TO ACHIEVE A TRAVELLING WAVE STRUCTURE. THE IMPEDANCE WAS MEASURED USING THE WIRE METHOD, AND ACCURATE RESULTS ARE OBTAINED BY INTERPRETING THE FORWARD SCATTERING COEFFICIENT VIA THE LONG-FORMULA. THE FOUR KICKERS WITH THEIR CERAMIC BEAM TUBES CONTRIBUE AT Z/N-0.22 OMEGA/RING IN THE INTERESTING FREQUENCY RANGE FROM 0.1 TO 1 BHZ, AND LESS ABOVE.
KISS conditioning of the LHC injection kickers
During routine operation the LHC injection kickers (MKI) will only be used during a short interval of time at the beginning of each LHC cycle, which will then last for several hours. During the LHC ramping and coasting the kickers cannot be pulsed: some high voltage de-conditioning may occur during this time, which could affect the high voltage performance of the kicker magnets at the next injection. Hence restarting the MKI pulsing immediately at its nominal voltage, after several hours of inactivity, may constitute a significant risk of sparking in the magnets and thus deterioration of the magnets and could hence cause major downtime for the LHC machine. To reduce this risk considerably a "KISS" (Kicker Injection Soft Start) process has been implemented into the system and will be executed before each injection run, thus being carried out in parallel with all the other LHC setting-up procedures prior to beam injection. During the "KISS" process, the kickers will automatically be pre-conditioned, under software control via the CCC, and the MKI magnets operated up to a voltage slightly beyond their nominal high voltage operating point. The "KISS" process is based around the known and proven "Automatic Magnet Conditioning" process specifically designed for the MKI kicker magnets.
ALL-FERRITE RHIC INJECTION KICKER
Ion beams are transferred from the AGS into RHIC in boxcar fashion as single bunches. The nominal design assumes 60 bunches per ring but increasing the number of bunches to gain luminosity is possible, thereby requiring injection kickers with a shorter rise time. The original injection system consists of traveling-wave dielectric loaded kicker magnets and a Blumlein pulser with a rise time adequate for the present operation. Voltage breakdown in the dielectric kickers suggested the use of all-ferrite magnets. In order to minimize the conversion cost, the design of the all-ferrite kicker uses the same components as the dielectric loaded units. The all-ferrite kickers showed in bench measured good breakdown properties and a current rise time of < 50 ns. A prototype kicker has been installed in the blue ring and was tested with beam. Beam measurements indicate suitability of all-ferrite kicker magnets for upgraded operation.
ALL-FERRITE RHIC INJECTION KICKER
2001-06-18
Ion beams are transferred from the AGS into RHIC in boxcar fashion as single bunches. The nominal design assumes 60 bunches per ring but increasing the number of bunches to gain luminosity is possible, thereby requiring injection kickers with a shorter rise time. The original injection system consists of traveling-wave dielectric loaded kicker magnets and a Blumlein pulser with a rise time adequate for the present operation. Voltage breakdown in the dielectric kickers suggested the use of all-ferrite magnets. In order to minimize the conversion cost, the design of the all-ferrite kicker uses the same components as the dielectric loaded units. The all-ferrite kickers showed in bench measured good breakdown properties and a current rise time of < 50 ns. A prototype kicker has been installed in the blue ring and was tested with beam. Beam measurements indicate suitability of all-ferrite kicker magnets for upgraded operation.
A New Slotted-Pipe Kicker Magnet for BEPCII Storage Ring
The requirements of BEPCII injecting kicker magnets are so severe. In the range of ?x=±20mm, the field uniformity is required to be better than ±1% in the central plane, ±2% in the y=5mm plane and ±5% in y=10mm plane, while the effective beam impedance of each kicker magnet must be lower than 0.025O. For the large aperture of vacuum chamber and the fast risetime of kicker magnetic field, the two schemes of low impedance kicker magnets used in other accelerator labs in the world are not adaptive to the BEPCII storage ring. A new slotted-pipe kicker magnet, which uses the ceramic bars with metal coating films as the image current conducting paths, proposed in this article solves the difficult problems of BEPCII kicker magnet design. And the successful construction of a prototype has demonstrated that the new scheme of kicker magnets is viable and the structure design of the kicker magnet is reasonable.
Test of very fast kicker for TESLA damping ring
We describe a very fast kicker with unique combination of high repetition rate and short pulse width. Constructionally, the device is a symmetrical counter traveling wave stripline kicker fed by semiconductor high-voltage pulse generator. Experimentally tested kicker has a full pulse width of about 7 ns, 1.4 MHz repetition rate and maximum kick strength of the order of 3 G{center_dot}m. Recent achievements in high-voltage semiconductor field-effect transistors (FET) technology and goal-specific optimization of the kicker parameters allow many-fold increase of the strength, and the kicker can be very useful tool for bunch-by-bunch injection/extraction and other accelerator applications. 4 refs., 3 figs.
Test of very fast kicker for TESLA damping ring
1997-04-01
We describe a very fast kicker with unique combination of high repetition rate and short pulse width. Constructionally, the device is a symmetrical counter traveling wave stripline kicker fed by semiconductor high-voltage pulse generator. Experimentally tested kicker has a full pulse width of about 7 ns, 1.4 MHz repetition rate and maximum kick strength of the order of 3 G{center_dot}m. Recent achievements in high-voltage semiconductor field-effect transistors (FET) technology and goal-specific optimization of the kicker parameters allow many-fold increase of the strength, and the kicker can be very useful tool for bunch-by-bunch injection/extraction and other accelerator applications. 4 refs., 3 figs.
LHC Kicker Beam-Impedance Calculation
1998-10-01
Longitudinal and transverse beam impedances are calculated for the injection kickers designed for use in the CERN large hadron col- Iider. These combine the contributions of a ceramic beam tube with conducting stripes and a traveling-wave kicker magnet. The results show peak impedances of 1300 ohm longitudinal and 8 Mfl/m trans- verse for four units per ring.
Magnetic Field Measurement on a Refined Kicker
To prepare for the operation of top-up mode and increase the efficiency of injection at storage ring, National Synchrotron Radiation Research Center (NSRRC) has upgraded the kicker magnets and power supply. We have built up a new magnetic field measurement system to test the kicker. This system, including a search coil and a coil loop, can map the field and take the first integral of field automatically. We also simulate the trajectory of electron beam by pulsed wire method of field measurement. We analyze the performance of the kicker system in this paper.
Considerations on a new fast extraction kicker concept for SPS
An alternative extraction kicker concept is investigated for the SPS, based on open C-type kickers and a fast-bumper system. The beam is moved into the kicker gap some tens of ms before extraction. The concept is illustrated in detail with the LSS4 extraction from the SPS very similar parameters and considerations apply to LSS6. A similar concept could also be conceived for injection but is more difficult due to the larger beam size. The technical issues are presented and the potential impact on the machine impedance outlined.
LHC injection and dump protection
The machine protection against fast failures including injection or dump kickers relies on fixed and movable devices. Results will be shown from the low-intensity beam commissioning of the moveable injection protection devices in the SPS to LHC transfer lines and downstream of the LHC injection kickers, and of the LHC dump protection elements in IR6. This paper is almost exclusively focussing on the issues arising during the 2009 commissioning. The implications of these results and a commissioning status report with the planning for 2010 will be addressed.
The inner surfaces of the 248 m SNS accumulator ring vacuum chambers are coated with ~100 nm of titanium nitride (TiN) to reduce the secondary electron yield (SEY) of the chamber walls. All the ring inner surfaces are made of stainless or inconel, except those of the injection and extraction kickers. Ceramic vacuum chambers are used for the 8 injection kickers to avoid shielding of a fast-changing kicker field and to reduce eddy current heating. The internal diameter was coated with Cu to reduce the beam coupling impedance and provide passage for beam image current, and a TiN overlayer to reduce SEY. The ferrite surfaces of the 14 extraction kicker modules were coated with TiN to reduce SEY. Customized masks were used to produce coating strips of 1 cm x 5 cm with 1 to 1.5 mm separation among the strips. The masks maximized the coated area to more than 80%, while minimizing the eddy current effect to the kicker rise time. The coating method, as well as the physical and electromagnetic properties of the coatings for both types of kickers will be summarized, with emphasis on the effect to the beam and the electron cloud buildup.
1997-07-01
During the RHIC sextant test in January 1997 beam was injected into a sixth of one of the rings for the first time. The authors describe the injection zone and its bottlenecks. They report on the commissioning of the injection system, on beam based measurements of the kickers and the application program to steer the beam.
Design Considerations of Fast Kicker Systems for High Intensity Proton Accelerators
2001-01-01
In this paper, we discuss the specific issues related to the design of the Fast Kicker Systems for high intensity proton accelerators. To address these issues in the preliminary design stage can be critical since the fast kicker systems affect the machine lattice structure and overall design parameters. Main topics include system architecture, design strategy, beam current coupling, grounding, end user cost vs. system cost, reliability, redundancy and flexibility. Operating experience with the Alternating Gradient Synchrotron injection and extraction kicker systems at Brookhaven National Laboratory and their future upgrade is presented. Additionally, new conceptual designs of the extraction kicker for the Spallation Neutron Source at Oak Ridge and the Advanced Hydrotest Facility at Los Alamos are discussed
Design Considerations of Fast Kicker Systems for High Intensity Proton Accelerators
In this paper, we discuss the specific issues related to the design of the Fast Kicker Systems for high intensity proton accelerators. To address these issues in the preliminary design stage can be critical since the fast kicker systems affect the machine lattice structure and overall design parameters. Main topics include system architecture, design strategy, beam current coupling, grounding, end user cost vs. system cost, reliability, redundancy and flexibility. Operating experience with the Alternating Gradient Synchrotron injection and extraction kicker systems at Brookhaven National Laboratory and their future upgrade is presented. Additionally, new conceptual designs of the extraction kicker for the Spallation Neutron Source at Oak Ridge and the Advanced Hydrotest Facility at Los Alamos are discussed.
The coupling impedance of the RHIC injection kicker system
1997-07-01
In this paper, results from impedance measurements on the RHIC injection kickers are reported. The kicker is configured as a {open_quotes}C{close_quotes} cross section magnet with interleaved ferrite and high-permittivity dielectric sections to achieve a travelling wave structure. The impedance was measured using the wire method in which a resistive match provides a smooth transition from the network analyzer to the reference line in the set-up. Accurate results are obtained by interpreting the forward scattering coefficient via the log-formula. The four kickers with their ceramic beam tubes contribute a Z/n = 0.22 {Omega}/ring in the interesting frequency range from 0.1 to 1 GHz, and less above. At frequencies above {approximately}100 MHZ, the impedance is ferrite dominated and not affected by the kicker terminations. Below 100 MHz, the Blumlein pulser with the {approximately}75 m feeding cables is visible in the impedance but makes no significant contribution to the results. The measurements show that the kicker coupling impedance is tolerable without the need for impedance reducing measures.
Very fast kicker for accelerator applications
We describe a very fast counter traveling wave kicker with a full pulse width of about 7 ns. Successful test experiment has been done with hi-tech semiconductor technology FET pulse generator with a MHz- range repetition rates and maximum kick strength of the order of 3 G{center_dot}m. Further. increase of the strength seems to be quite possible with the FET pursers, that makes the kicker to be very useful tool for bunch-by-bunch injection/extraction and other accelerator applications.
In order to help the operation of constant current, the optics of booster to storage ring transport line (BTS) design is reinvestigated. The initial twiss parameters are derived by measurement. The optics of the transport line is readjusted according to the measured initial beam parameters. The design of pulse width of the injection kicker is also changed from 1.2μsecond to 2.0μsecond. The injection scheme is reviewed and the effects of the kicker error on both injected beam and stored beam are investigated and shown in this report.
Fast kicker magnets are used to inject beam into and eject beam out of the CERN SPS accelerator ring. These kickers are generally ferrite loaded transmission line type magnets with a rectangular shaped aperture through which the beam passes. Unless special precautions are taken the impedance of the ferrite yoke can provoke significant beam induced heating, even above the Curie temperature of ferrite. In addition the impedance can contribute to beam instabilities. In this paper different variants of the coaxial wire method, both for measuring longitudinal and transverse impedance, are briefly discussed in a tutorial manner and do's and don'ts are shown on practical examples. In addition we present the results of several impedance measurements for SPS kickers using the wire method and compare those results with theoretical models.
Measurement and analysis of SPS kicker magnet heating and outgassing with Different Bunch Spacing
Fast kicker magnets are used to inject beam into and eject beam out of the CERN SPS accelerator ring. These kickers are generally ferrite loaded transmission line type magnets with a rectangular shaped aperture through which the beam passes. Unless special precautions are taken the impedance of the ferrite yoke can provoke significant beam induced heating, over several hours, even above the Curie temperature of the ferrite. At present the nominal bunch spacing in the SPS is 25 ns, however for an early stage of LHC operation it is preferable to have 50 ns bunch spacing. Machine Development (MD) studies have been carried out with an inter-bunch spacing of 25 ns, 50 ns or 75 ns. For some of the SPS kicker magnets the 75 ns bunch spacing resulted in considerable beam induced heating. In addition the MDs showed that 50 ns bunch spacing could result in a very rapid pressure rise in the kicker magnet and thus cause an interlock. This paper discusses the MD observations of the SPS kickers and analyses the available data to provide explanations for the phenomena: possible remedies are also discussed.
Commissioning of the Control System for the LHC Beam Dump Kicker System
The beam dumping system of the Large Hadron Collider (LHC) provides a loss-free fast extraction of the circulating beams. It consists per ring of 15 extraction kickers, followed by 15 septum magnets, 10 dilution kickers and an external absorber. A dump request can occur at any moment during the operation of the collider, from injection energy up to collision energy. All kickers must fire synchronously with the beam abort gap to properly extract the whole beam in one single turn into the extraction channel. Incorrect operation of the extraction kickers can lead to beam losses and severe damage to the machine. The control system of the LHC beam dump kickers is based on a modular architecture composed of 4 different sub-systems, each with a specific function, in order to detect internal failures, to ensure a correct extraction trajectory over the whole LHC operational range, to synchronise and distribute dumps requests, and to analyse the transient signals recorded during the beam dumping process. The control architecture is presented and the different steps performed for its validation, from the individual sub-systems tests to the final commissioning with beam, are described
Automatic conditioning of the LHC injection kickers
The LHC injection systems, located near the interaction regions 2 and 8, comprise 4 fast pulsed kicker magnets (MKI) per ring to bring the beam onto the orbit. Each magnet is housed in a separate vacuum tank. Their nominal operating voltage is 54 kV, and the nominal pulse length 7.86 s. To prepare these magnets for operation they are once assembled and baked out, gradually subjected to higher and higher voltages and greater pulse lengths, until their voltage holding capability is sufficiently beyond the nominal operating conditions. In the past this "conditioning" was carried out manually, and thus a manpower-intensive, and also technically not optimal procedure. To overcome these drawbacks a program has been developed, running in a Programmable Logic Controller (PLC), which has been used to condition the full suite of LHC injection kickers automatically.
Design of the injection kicker magnet system for CERN's 14 TeV proton collider LHC
Two counter-rotating proton beams will be injected into the LHC at an energy of 450 GeV by two kicker magnet systems, producing magnetic field pulses of approximately 750 ns rise time and 6.6 s flat top duration. To avoid dilution of the beam emittance during injection, a stringent design requirement of the system is a flat top ripple of the magnetic field of less than 0.5%. Both injection systems are composed of 4 travelling wave kicker magnets of 2.17 m length each, powered by pulse forming networks (PFN's) and matched to their characteristic impedance. To achieve the high required kick strength of 1.2 Tm, for a compact and cost efficient design, a comparably low characteristic impedance of 5 has been chosen. The electrical circuit of the system is being designed with the help of PSpice computer modelling. Most known parasitic elements are included in the model to obtain a realistic pulse response prediction. The present paper reports on design and modeling results of the LHC injection kicker magnet system that has several novel and demanding design requirements.
A fast injection kicker system for the Tevatron
2001-07-25
A new proton injection kicker system is required for the Tevatron in the Run II era. The new system was designed to supply 1.25 kG-m into a magnetic aperture of 48 mm vertical x 71 mm horizontal x 5 m long with a 396 ns bunch spacing. The system was designed to be upgraded to 132 ns bunch spacing with additional pulse supplies. The system design tradeoffs needed to meet these goals is discussed. These include the system topology, the system impedance and the number of magnets. This system has been installed in the Tevatron.
The conceptual considerations of a fast injection system for protons and ions in the proposed PS2 accelerator are presented. Initial design parameters of the injection septum and kicker systems are derived, taking into account rise and fall times, apertures and machine optics. The requirements for an injection dump used for failures are described. Possible limitations and technical issues are outlined.
Tevatron proton injection kicker waveform analysis
1995-01-01
On July 25, 1995 a shift of Tevatron beam studies was devoted to examining the shape of the E17 kicker waveform. The purpose of this study was to determine how the kicker may effect the emittance of the Protons once collider operation changed to 36 bunch operation. The kicker was setup to give the most uniform flattop with approximately the correct flattop length. To do this, all 22 cells of the pulse forming network were connected and the predets for the tube timing were set as follows: Main = 1.0 {micro}sec; Clip = 6.0 {micro}sec; and Dump = 4.0 {micro}sec. The data was collected by varying the trigger of the kicker and observing the response of the beam with the BPM system. This timer, the beam synch delay out of a 279 module, only has 7 bucket resolution. Thus any waveform variation smaller than 131 nsec (or greater than 7.6 MHz) will not be observed. The data for the flattop was collected in a different way than the data for the rising edge and falling edge. To collect the flattop data the injection closure was tuned to give a minimum turn by turn oscillation. Under these conditions, a first turn flash frame was recorded as a reference. As the kicker timing was varied, the positions at E17, E19 and E26 were recorded. Also, the amplitude of turn by turn oscillation as measured by the beam line tuner system at D49 was recorded. The effect of the kick given by the timing change was recorded for times that map out the complete flattop of the kicker wave form. In figure 1, the turn by turn amplitude is shown vs kicker trigger setting (in units of MREV). Because the kicker is being delayed, and the beam is always arriving at the same time, the rising edge of the kicker is actually on the right side of the plot, and the end of the flattop is on the left. The x's show the points in time that Protons will pass during 36 bunch operation. The first bunch will pass as the initial transient has stabilized at 1.925 MREV. it can be seen that the flattop is about 400 nsec short, so the clip tube timing will have to be adjusted. Note that this is feasible in that the maximum allowable rise time is 2.617 micro-sec while the rise time to where the oscillation dies out if 2.605 micro-sec.
Beam-Based Measurement of the Waveform of the LHC Injection Kickers
Proton and ion beams are injected into LHC at 450 GeV by two kicker magnet systems, producing magnetic field pulses of up to 7.8 ms flat top duration with rise and fall times of not more than 900 ns and 3 ms, respectively. Both systems are composed of four travelling wave kicker magnets, powered by pulse forming networks. One of the stringent design requirements of these systems is a field flat top and postpulse ripple of less than 0.5 %. A carefully matched high bandwidth system is required to obtain the required pulse response. Screen conductors are placed in the aperture of the kicker magnet to provide a path for the image current of the, high intensity, LHC beam and screen the ferrite against wake fields. However, these conductors affect the field pulse response. Recent injection tests provided the opportunity to directly measure the shape of the kick field pulse, with high accuracy, using a pilot beam. This paper details the measurements and compares the results with predictions and laboratory measurements.
MI Gap Clearing Kicker Magnet Design Review
2008-10-01
The kicker system requirements were originally conceived for the NOvA project. NOvA is a neutrino experiment located in Minnesota. To achieve the desired neutrino flux several upgrades are required to the accelerator complex. The Recycler will be used as a proton pre-injector for the Main Injector (MI). As the Recycler is the same size as the MI, it is possible to do a single turn fill ({approx}11 {micro}sec), minimizing the proton injection time in the MI cycle and maximizing the protons on target. The Recycler can then be filled with beam while the MI is ramping to extract beam to the target. To do this requires two new transfer lines. The existing Recycler injection line was designed for 10{pi} pbar beams, not the 20{pi} proton beams we anticipate from the Booster. The existing Recycler extraction line allows for proton injection through the MI, while we want direct injection from the Booster. These two lines will be decommissioned. The new injection line from the MI8 line into the Recycler will start at 848 and end with injection kickers at RR104. The new extraction line in the RR30 straight section will start with a new extraction kicker at RR232 and end with new MI injection kickers at MI308. Finally, to reduce beam loss activation in the enclosure, a new gap clearing kicker will be used to extract uncaptured beam created during the slip stack injection process down the existing dump line. It was suggested that the MI could benefit from this type of system immediately. This led to the early installation of the gap clearing system in the MI, followed by moving the system to Recycler during NOvA. The specifications also changed during this process. Initially the rise and fall time requirements were 38 ns and the field stability was {+-}1%. The 38 ns is based on having a gap of 2 RF buckets between injections. (There are 84 RF buckets that can be filled from the Booster for each injection, but 82 would be filled with beam. MI and Recycler contain 588 RF buckets.) A rough cost/benefit analysis showed that increasing the number of empty buckets to 3 decreased the kicker system cost by {approx}30%. This could be done while not extending the running time since this is only a 1% reduction in protons per pulse, hence the rise and fall time are now 57 ns. Additionally, the {+-}1% tolerance would have required a fast correction kicker while {+-}3% could be achieved without this kicker. The loosened tolerance was based on experience on wide band damping systems in the MI. A higher power wideband damping system is a better use of the resources as it can be used to correct for multiple sources of emittance growth. Finally, with the use of this system for MI instead of Recycler, the required strength grew from 1.2 mrad to 1.7 mrad. The final requirements for this kicker are listed.
Steel Tape-wound Cut Cores as Magnet Yokes for the Beam Dump Kickers of the Large Hadron Collider
Fast pulsed magnets, also called kickers, are used in particle accelerators for beam injection, extraction and similar applications. To excite these magnets, typically current pulses with rise and fall times in the range of 100 ns to 10 s, with pulse duration of up to 100 s and amplitudes in the order of kilo Amperes, are used. The short rise time imposes low inductance circuits and high voltage operation. The yokes are usually made out of ferrite, with reaches field saturation at about 0.5 T.
COLLECTIVE EFFECTS AND THEIR CONTROL AT THE SPALLATION NEUTRON SOURCE RING.
One of the primary tasks in the design of the Spallation Neutron Source (SNS) ring is to control collective effects including space charge, transverse and longitudinal instabilities, and electron cloud. Transverse painting is used to alleviate space charge force; longitudinal painting along with chromatic sextupoles are used to enhance Landau damping; injection kicker vacuum pipes are carefully shielded, and extraction kicker impedances are measured in detail and optimized; beam halo, beam loss and electron production are minimized; finally, damping systems at various frequencies are planned. This paper summarizes these design implementations.
SNS Injection and Extraction Devices
The Spallation Neutron Source (SNS) is a second generation pulsed neutron source (1.5 MW) and is presently in the sixth year of a seven-year construction cycle at Oak Ridge National Laboratory. The operation of the facility will begin in 2006. The most stringent requirement for the SNS accelerator complex is to allow hands-on maintenance. Operational experiences show that the most losses occur in the injection and extraction. SNS accumulator ring injection and extraction has been design with grate care to reduce uncontrolled losses. Injection systems consist of fast programmable kicker magnets and DC dump magnets to paint the beam in transverse phase space. Extraction systems consist of fast kicker magnets and a Lamberton magnet to extract beam in single turn. Paper will discuss design, construction and testing of these devices.
Dynamic Devices: Pickups and Pickers
1986-08-01
A large proportion of the dynamic devices used to interact with the charged-particle beams in accelerators or storage rings can be classified as pickups or kickers. These devices act through time-varying electromagnetic fields either to extract information about the particle's motion or to effect a change in that motion. A given configuration of electrodes may be used either as a pickup or as a kicker; that duality will be addressed in this paper. An example of a simple electrode is the loop antenna, which may be made in the shape of an electrical stripline at the side of a beam chamber. This electrode.picks up a signal from the beam current by intercepting time-varying magnetic flux and image charges of the beam. One can also understand that the difference signal from two such striplines placed on opposite sides of the beam will give information on the beam's transverse position. This same electrode, if externally excited as a kicker, can produce transverse forces through its magnetic field acting on moving charges; and its electric fields in the direction of the particle motion produce its effects as a longitudinal kicker. Electrodes for a particular application call for response over a particular range of frequencies. The stripline electrodes provide useful coupling over a range greater than one octave, centered about frequencies usually between 100 EIHz and 10 GHz. In this same frequency region, a narrow-band device is the r.f. cavity which can be employed as either a sensitive pickup or a high-power accelerating or deflecting electrode; the rf accelerating system of a particle accelerator is a specialized example of such a kicker. A particular wave form with short rise time, then long flat dwell, is called for in the pulsed magnet kicker used to inject beam onto a closed orbit. Depending on the application, analysis, and description, an electrode's performance may be in either the time domain or the frequency domain. relations between longitudinal and transverse effects, and between the responses as pickup and as kicker. We shall see that dynamic effects are entirely determined by the longitudinal electric fields in the direction of the beam current when the electrode is excited as a kicker; and as a corollary, absence of longitudinal electric fields guarantees no coupling to beam particles. Response functions that serve as figures of merit will be defined. We shall then analyze the responses of specific examples of pickups and kickers. Finally, an approach to the calculation of the transverse variation of coupling over the electrode aperture will be presented.
A Pulsed Modulator Power Supply for the g-2 Muon Storage Ring Injection Kicker
1999-01-01
This paper describes the pulse modulator power supplies used to drive the kicker magnets that inject the muon beam into the g-2 storage ring that has been built at Brookhaven. Three modulators built into coaxial structures consisting of a series circuit of an energy storage capacitor, damping resistor and a fast thyratron switch are used to energize three magnets that kick the beam into the proper orbit. A 100 kV charging power supply is used to charge the capacitor to 95 kV. the damping resistor shapes the magnet current waveform to a 450 nanosecond half-sine to match the injection requirements. this paper discusses the modulator design, construction and operation
A Pulsed Modulator Power Supply for the g-2 Muon Storage Ring Injection Kicker
This paper describes the pulse modulator power supplies used to drive the kicker magnets that inject the muon beam into the g-2 storage ring that has been built at Brookhaven. Three modulators built into coaxial structures consisting of a series circuit of an energy storage capacitor, damping resistor and a fast thyratron switch are used to energize three magnets that kick the beam into the proper orbit. A 100 kV charging power supply is used to charge the capacitor to 95 kV. the damping resistor shapes the magnet current waveform to a 450 nanosecond half-sine to match the injection requirements. this paper discusses the modulator design, construction and operation.
A Pulsed Modulator Power Supply for the g-2 Muon Storage Ring Injection Kicker
1999-03-29
This paper describes the pulse modulator power supplies used to drive the kicker magnets that inject the muon beam into the g-2 storage ring that has been built at Brookhaven. Three modulators built into coaxial structures consisting of a series circuit of an energy storage capacitor, damping resistor and a fast thyratron switch are used to energize three magnets that kick the beam into the proper orbit. A 100 kV charging power supply is used to charge the capacitor to 95 kV. the damping resistor shapes the magnet current waveform to a 450 nanosecond half-sine to match the injection requirements. this paper discusses the modulator design, construction and operation.
A PULSED MODULATOR POWER SUPPLY FOR THE G-2 MUON STORAGE RING INJECTION KICKER.
This paper describes the pulse modulator power supplies used to drive the kicker magnets that inject the muon beam into the 8-2 storage ring that has been built at Brookhaven National Laboratory. Three modulators built into coaxial structures consisting of a series circuit of an energy storage capacitor, a damping resistor and a fast thyratron switch are used to energize three magnets that kick the beam into the proper orbit. A 100 kV charging power supply is used to charge the capacitor to 95kV. The damping resistor shapes the magnet current waveform to a 450 nanosecond half-sine to match the injection requirements. This paper discusses the modulator design, construction and operation.
A PULSED MODULATOR POWER SUPPLY FOR THE G-2 MUON STORAGE RING INJECTION KICKER.
2003-03-01
This paper describes the pulse modulator power supplies used to drive the kicker magnets that inject the muon beam into the 8-2 storage ring that has been built at Brookhaven National Laboratory. Three modulators built into coaxial structures consisting of a series circuit of an energy storage capacitor, a damping resistor and a fast thyratron switch are used to energize three magnets that kick the beam into the proper orbit. A 100 kV charging power supply is used to charge the capacitor to 95kV. The damping resistor shapes the magnet current waveform to a 450 nanosecond half-sine to match the injection requirements. This paper discusses the modulator design, construction and operation.
The injection and extraction of SSRF booster
2008-01-01
The layout of injection and extraction system were introduced in this paper. The horizontal and vertical injection acceptance are about 23 pimmcentre dotmrad and 37 pimmcentre dotmrad, respectively, while emittance of the injected beam is 9 pimmcentre dotmrad (3sigma). This ensures the high injection efficiency. Three slow kickers can form a good bump. The inside position of the entrance of septum is set to 15 mm, where the bumped beam and the extraction beam are 10 mm and 22 mm, respectively, far from the booster central orbit. (authors)
1980-02-01
The AA in its final stage of construction, before it disappeared from view under concrete shielding. Antiprotons were first injected, stochastically cooled and accumulated in July 1980. From 1981 on, the AA provided antiprotons for collisions with protons, first in the ISR, then in the SPS Collider. From 1983 on, it also sent antiprotons, via the PS, to the Low-Energy Antiproton Ring (LEAR). The AA was dismantled in 1997 and shipped to Japan.
Uptake and release of adrenal ascorbic acid in the guinea pig after injection of ACTH
1987-09-01
The effect of a single injection of ACTH (3 IU/100 g body weight) on the distribution of ascorbic acid (AA) and radiolabeled AA in 20 tissues was studied in adult male guinea pigs consuming 500 mg AA/kg diet. Saline- or ACTH-injected animals were simultaneously injected with (1-/sup 14/C)AA, and killed at 0.5, 1, 2, 4 and 6 h after injection. There was no significant difference between treatments in the weight of any tissue over the 6-h experimental period. As anticipated, the concentration of AA in the adrenals of animals injected with ACTH was 33% of that of animals injected with saline at 4 h. Unexpectedly, the concentration of radiolabeled AA in the adrenals at 0.5 h after ACTH injection was 172% of that after saline injection. The concentration of radiolabeled AA in the adrenal of the saline-injected animals increased slowly over time to reach a level similar to that of ACTH-injected animals by 6 h. There was no effect of ACTH on the level of AA or uptake in any of the other tissues examined. These results demonstrate that a single dose of ACTH markedly influences the retention of AA in the adrenal gland without similarly altering retention of AA in other tissues. Furthermore, ACTH treatment causes both accelerated uptake and release of AA into the adrenals.
1983-11-01
The injection and extraction mechanisms for the LAMPF II rings are discussed. The designs refer to current five-sided machines designed and labeled LIIA19 and LIIS19. Extraction from LIIA19 and injection into LIIS19 are effected in a single turn using fast kickers and Lambertson septa. Storage ring extraction will be via half-integral resonant extraction and will utilize electrostatic and Lambertson extraction septa.
A Continuous Injector-Ejector Scheme for Damping Rings
In this paper we describe a new injection-ejection scheme for damping rings, in which several bunches are simultaneously stored and cooled.The application of kickers becomes difficult when the injection and ejection frequency exceeds several hundred Hz.It is proposed to use several cavities in a deflecting mode at different frequencies in order to select a single pulse out of the stored pulse train.
LHC Transverse Feedback System$$bFirst Results of Commissionning
A powerful transverse feedback system ("Damper") has been installed in LHC. It will stabilise the high intensity beam against coupled bunch transverse instabilities in a frequency range from 3 kHz to 20 MHz and at the same time damp injection oscillations originating from steering errors and injection kicker ripple. The LHC Damper can also be used as means of exciting transverse oscillations for the purposes of abort gap cleaning and tune measurement. The LHC Damper includes 4 feedback systems on 2 circulating beams (in other words one feedback system per beam and plane). Every feedback system consists of 4 electrostatic kickers, 4 push-pull wide band power amplifiers, 8 preamplifiers, two digital processing units and 2 beam position monitors with low-level electronics. The power and low-level subsystem layout is described along with first results from the commissioning of 16 power amplifiers and 16 electrostatic kickers located in the LHC tunnel. The achieved performance is compared with earlier predictions and requirements for injection damping and instability control. Requirements and first measurements of the performance of the power and low-level subsystems are summarized.
Protection Level during Extraction, Transfer and Injection into the LHC
ailures during the LHC transfer and injection process cannot be excluded and beam loss with the foreseen intensities and energies will cause serious equipment damage. Consequences of equipment failures such as kicker erratics, power converter faults, etc. are investigated by means of a Monte Carlo based on MAD-X tracking with a full aperture model of the transfer line and the injection region. Geometrical and optical mismatch, orbit tolerances, mechanical tolerances for settings of protection elements, power converter ripples, misalignment of elements, etc. are all taken into account. The required performance of the protection system is discussed. The overall protection level for the LHC and the transfer lines during injection is presented.
Impedance Measurements on the LHC Injection Kicker Prototype
The longitudinal beam coupling impedance of an LHC injection kicker model(not yet fully equipped) has been measured by means of the coaxial wiremethod. To get a reasonable estimate of the impedance, three contributionsshould be taken into account. These contributions are the effect of theferrite yoke which absorbs electromagnetic energy, the effect of the coldand hot conductors which alter the shape of the TEM-like field of thebeam, and possibly cavity resonances in the tank. Since the benchmeasurement of this model indicates very high energy deposition in thisstructure with the LHC beam, also another model in which the ferrites andthe tank are shielded from the beam by an alumina tube which has a numberof metal strips on the inner surface, was examined. The comparison of twomeasurements shows good reduction of the coupling impedance by this beamscreen technique.
16 AAS/AIAA Space Flight Mechanics Conference
The three vehicles would rendezvous and mate in low Earth ... The mission is also extremely robust to injection vehicle delivery dispersions.33 .... Satellites Including Higher Order Gravity Fields, AAS/AIAA Space Flight ...
The Antiproton Accumulator (AA)
1980-06-01
A section of the AA where the dispersion (and hence the horizontal beam size) is large. One can distinguish (left to right): A large vacuum-tank, a quadrupole (QDN09*), a bending magnet (BST08), another vacuum-tank, a wide quadrupole (QFW08) and (in the background) a further bending magnet (BST08). The tanks are covered with heating tape for bake-out. The tank left of QDN09 contained the kickers for stochastic pre-cooling (see 790621, 8002234, 8002637X), the other one served mainly as vacuum chamber in the region where the beam was large. Peter Zettwoch works on QFW08. * see: H. Koziol, Antiproton Accumulator Parameter List, PS/AA/Note 84-2 (1984) See under 7911303, 7911597X, 8004261 and 8202324. For photos of the AA in different phases of completion (between 1979 and 1982) see: 7911303, 7911597X, 8004261, 8004608X, 8005563X, 8005565X, 8006716X, 8006722X, 8010939X, 8010941X, 8202324, 8202658X, 8203628X .
The Beam Screen for the LHC Injection Kicker Magnets
The two LHC injection kicker magnet systems must each produce a kick of 1.2 T.m with a flattop duration variable up to 7.86 s, and rise and fall times of less than 0.9 s and 3 s, respectively. Each system is composed of four 5 transmission line kicker magnets with matched terminating resistors and pulse forming networks (PFN). The LHC beam has a high intensity, hence a beam screen is required in the aperture of the magnets This screen consists of a ceramic tube with conducting ?stripes? on the inner wall. The stripes provide a path for the image current of the beam and screen the magnet ferrites against Wake fields. The stripes initially used gave adequately low beam impedance however stripe discharges occured during pulsing of the magnet: hence further development of the beam screen was undertaken. This paper presents options considered to meet the often conflicting needs for low beam impedance, shielding of the ferrite, fast field rise time and good electrical and vacuum behaviour.
SUMMARY ON TITANIUM NITRIDE COATING OF SNS RING VACUUM CHAMBERS.
The inner surfaces of the 248 m Spallation Neutron Source (SNS) accumulator ring vacuum chambers are coated with {approx}100nm of titanium nitride (TiN) to reduce the secondary electron yield (SEY) of the chamber walls. There are approximately 135 chambers and kicker modules, some up to 5m in length and 36cm in diameter, coated with TiN. The coating is deposited by means of reactive DC magnetron sputtering -using a - cylindrical cathode with internal permanent magnets. This cathode configuration generates a deposition-rate sufficient to meet the required production schedule and produces stoichiometric films with good adhesion, low SEY and acceptable outgassing. Moreover, the cathode magnet configuration allows for simple changes in length and has been adapted to coat the wide variety of chambers and components contained within the arcs, injection, extraction, collimation and RF straight sections. Chamber types and quantities as well as the cathode configurations are presented herein. The unique coating requirements of the injection kicker ceramic chambers and the extraction kicker ferrite surface will be emphasized. A brief summary of the salient coating properties is given including the interdependence of SEY as a function of surface roughness and its effect on outgassing.
SUMMARY ON TITANIUM NITRIDE COATING OF SNS RING VACUUM CHAMBERS.
2005-05-16
The inner surfaces of the 248 m Spallation Neutron Source (SNS) accumulator ring vacuum chambers are coated with {approx}100nm of titanium nitride (TiN) to reduce the secondary electron yield (SEY) of the chamber walls. There are approximately 135 chambers and kicker modules, some up to 5m in length and 36cm in diameter, coated with TiN. The coating is deposited by means of reactive DC magnetron sputtering -using a - cylindrical cathode with internal permanent magnets. This cathode configuration generates a deposition-rate sufficient to meet the required production schedule and produces stoichiometric films with good adhesion, low SEY and acceptable outgassing. Moreover, the cathode magnet configuration allows for simple changes in length and has been adapted to coat the wide variety of chambers and components contained within the arcs, injection, extraction, collimation and RF straight sections. Chamber types and quantities as well as the cathode configurations are presented herein. The unique coating requirements of the injection kicker ceramic chambers and the extraction kicker ferrite surface will be emphasized. A brief summary of the salient coating properties is given including the interdependence of SEY as a function of surface roughness and its effect on outgassing.
METALLIZATION OF CERAMIC VACUUM CHAMBERS FOR SNS RING INJECTION KICKER MAGNETS.
Ceramic chambers will be used in the pulsed kicker magnets for the injection of H{sup -} into the US Spallation Neutron Source (SNS) accumulator ring. There are two reasons for using ceramic chambers in kickers: (1) to avoid shielding of a fast-changing external magnetic field by metallic chamber walls; and (2) to reduce heating due to eddy currents. The inner surfaces of the ceramic chambers will be coated with a conductive layer, possibly titanium (Ti) or copper with a titanium nitride (TiN) overlayer, to reduce the beam coupling impedance and provide passage for beam image current. This paper describes the development of sputtering method for the 0.83m long 16cm inner diameter ceramic chambers. Coatings of Ti, Cu and TiN with thicknesses up to 10 {micro}m were produced by means of DC magnetron sputtering. The difficulty of coating insulators was overcome with the introduction of an anode screen. Films with good adhesion, uniform longitudinal thickness, and conductivity were produced.
METALLIZATION OF CERAMIC VACUUM CHAMBERS FOR SNS RING INJECTION KICKER MAGNETS.
2002-04-22
Ceramic chambers will be used in the pulsed kicker magnets for the injection of H{sup -} into the US Spallation Neutron Source (SNS) accumulator ring. There are two reasons for using ceramic chambers in kickers: (1) to avoid shielding of a fast-changing external magnetic field by metallic chamber walls; and (2) to reduce heating due to eddy currents. The inner surfaces of the ceramic chambers will be coated with a conductive layer, possibly titanium (Ti) or copper with a titanium nitride (TiN) overlayer, to reduce the beam coupling impedance and provide passage for beam image current. This paper describes the development of sputtering method for the 0.83m long 16cm inner diameter ceramic chambers. Coatings of Ti, Cu and TiN with thicknesses up to 10 {micro}m were produced by means of DC magnetron sputtering. The difficulty of coating insulators was overcome with the introduction of an anode screen. Films with good adhesion, uniform longitudinal thickness, and conductivity were produced.
High Voltage Measurements on Nine PFNs for the LHC Injection Kicker Systems
Each of the two LHC injection kicker magnet systems must produce a kick of 1.3 T.m with a flattop duration variable up to 7.86 microseconds, and rise and fall times of less than 900 ns and 3 microseconds, respectively. A kicker magnet system consists of four 5 Ohm transmission line magnets with matching terminating resistors, four 5 Ohm Pulse Forming Networks (PFN) and two Resonant Charging Power Supplies (RCPS). Nine PFNs, together with associated switch tanks, and dump switch terminating resistors have been built at TRIUMF and all have been tested at high voltage (54 kV) to ensure that the performance is within specification. This paper describes the HV measurements, compares these results with low voltage measurements and analyses the pulse performance of the PFNs. The measurements are compared with results from PSpice simulations and small discrepancies between the predictions and measurements are explained.
Bench measurements of the LHC injection kicker low frequency impedance properties
The LHC injection kicker contains a ceramic tube with inside printed metallic strips as a RF bypass in order to minimise the beam coupling impedance. These strips are capacitively coupled at one side to avoid eddy current during kicker transients. Experimentally it was found already earlier, using bench techniques, that in the region between 10 and 30 MHz certain resonances and thus peaks in the coupling impedance occur, related to the transition of the image current from the “cold conductor" to the bypass strips. The presence of these resonances has been reconfirmed as well as their properties. A practical method for reducing their influence by attaching lossy ferrite rings to the ends of the ceramic pipe is proposed and has partly been tested. As the present measurements were done on a mock-up for this RF bypass, which has limited validity towards higher frequencies, a full scale test should be repeated, once the first prototype of the 3 meter long ceramic chamber with printed bypass strips is available.
An Improved Beam Screen for the LHC Injection Kickers
The two LHC injection kicker magnet systems must produce a kick of 1.3 T.m with a flattop duration variable up to 7860 ns, and rise and fall times of less than 900 ns and 3000 ns, respectively. Each system is composed of two resonant charging power supplies (RCPSs) and four 5 WW transmission line kicker magnets with matched terminating resistors and pulse forming networks (PFNs). A beam screen is placed in the aperture of the magnets: the screen consists of a ceramic tube with conductors on the inner wall. The conductors provide a path for the image current of the, high intensity, LHC beam and screen the ferrite against Wake fields. The conductors initially used gave adequately low beam coupling impedance however inter-conductor discharges occurred during pulsing of the magnet: an alternative design was discharge free at the nominal operating voltage but the impedance was too high for the ultimate LHC beam. This paper presents the results of a new development undertaken to meet the often conflicting requirements for low beam coupling impedance, fast magnetic field risetime and good high voltage behaviour. High voltage test results and thermal measurements are also presented.
LHC Transverse Feedback System and its Hardware Commissioning
A powerful transverse feedback system ("Damper") has been installed in LHC. It will stabilise coupled bunch instabilities in a frequency range from 3 kHz to 20 MHz and at the same time damp injection oscillations originating from steering errors and injection kicker ripple. The transverse damper can also be used as an exciter for purposes of abort gap cleaning or tune measurement. The power and lowlevel systems layouts are described along with results from the hardware commissioning. The achieved performance is compared with earlier predictions and requirements for injection damping and instability control.
Transverse Resistive Wall Impedance for Multi-Layer Flat Chambers
2002-06-11
The transverse resistive wall impedance is calculated for arbitrary multi-layer vacuum chambers with a flat geometry. A finite thickness of the metal layer is important at impedance calculations for long machines like VLHC [1], thin coating of elements like injection kickers [2] and a closed orbit coherent stability analysis [3]. This paper uses ideas of our similar consideration for round vacuum chambers [4].
The PS Booster, PS and SPS Magnets for the next 25 years
This note provides information and analysis on the present status of the magnets installed in the CERN Proton Synchrotron Booster (PSB), the Proton Synchrotron (PS) and the Super Proton Synchrotron (SPS) in view of their possible operation for the next 25 years. The note does not cover the magnets installed in the transfer lines, neither it covers the fast injection/extraction magnets (septa and kickers).
THE EXTRACTION LAMBERTSON SEPTUM MAGNET OF THE SNS.
In the Spallation Neutron Source, after multiple injections to an accumulator ring, a final extraction delivers the full proton beam to the target, achieved by a series of kickers and a thin septum magnet. Here we discuss the lattice geometry, beam dynamics and optics, and the vacuum, electromagnetic and mechanical design aspects of the Extraction Lambertson Septum Magnet (ELS). Relevant data are established. Vector calculus is solved for pitch and roll angles, which are shown schematically in magnet sections.
THE EXTRACTION LAMBERTSON SEPTUM MAGNET OF THE SNS.
2005-05-16
In the Spallation Neutron Source, after multiple injections to an accumulator ring, a final extraction delivers the full proton beam to the target, achieved by a series of kickers and a thin septum magnet. Here we discuss the lattice geometry, beam dynamics and optics, and the vacuum, electromagnetic and mechanical design aspects of the Extraction Lambertson Septum Magnet (ELS). Relevant data are established. Vector calculus is solved for pitch and roll angles, which are shown schematically in magnet sections.
LHC Abort Gap Monitoring and Cleaning
Unbunched beam is a potentially serious issue in the LHC as it may quench the superconducting magnets during a beam abort. Unbunched particles, either not captured by the RF system at injection or leaking out of the RF bucket, will be removed by using the existing damper kickers to excite resonantly the particles in the abort gap. Following beam simulations, a strategy for cleaning the abort gap at different energies was proposed. The plans for the commissioning of the beam abort gap cleaning are described and first results from the beam commissioning are presented.
Beam transfer and extraction at LAMPF II
1983-01-01
Protons will be single-turn extracted from the LAMPF II synchrotron at 30 Hz. On alternate pulses they will be single-turn injected into a storage ring. Both processes utilize fast kickers and Lambertson septum magnets. Half-integer resonant extraction will be used to slow-extract the beam from the storage ring over a time spread of 1/15 s. The slow extraction occurs using electrostatic wire and iron septa.
The Impedance of Multi-layer Vacuum Chambers
Many components of the LHC vacuum chamber have multi-layered walls : the copper coated cold beam screen, the titanium coated ceramic chamber of the dump kickers, the ceramic chamber of the injection kickers coated with copper stripes, only to name a few. Theories and computer programs are available for some time already to evaluate the impedance of these elements. Nevertheless, the algorithm developed in this paper is more convenient in its application and has been used extensively in the design phase of multi-layer LHC vacuum chamber elements. It is based on classical transmission line theory. Closed expressions are derived for simple layer configurations, while beam pipes involving many layers demand a chain calculation. The algorithm has been tested with a number of published examples and was verified with experimental data as well.
Faults Detection on the LHC Beam Dump Kicker System
This report describes a proposal for fault detection on the LHC beam dump kicker system. As a result of a fault analysis two fault detection modules are proposed; A off-line test and a continuous surveillance. The fault detection, needing continues data, and the requirements to the data acquisition is given special attention. The off-line test declares the system, including stand-by components, fault tree prior to beam injection. the test comprises parameter estimation using the sensitivity approach requiring an ADC with better than 7 bit precision and a sampling frequency above 133kHz. The continuous surveillance comprises a model based fault detection method, based on analytical redundancy. The system requirements are a 14 bit DAC and an 16 bit ADC with a sample frequency above 1.54Hz.
Fast power supplies for kicker and thin septum magnets in a 1.2 GeV synchrotron radiation source
1991-01-01
The Maxwell Laboratories, Inc. (Maxwell) Model 1.2-400 Electron Storage Ring, which is being built for the LSU Center for Advanced Microstructures and Devices, is a 1.2 GeV Synchrotron which has a 200 Mev linac for injection of electrons into the storage ring. The injector section for merging the linac beam with the storage ring beam four kicker magnets for altering the course of the stored beam and a thin septum magnet for steering the linac beam. A detailed discussion of the electrical requirements for the fast power supplies for powering the magnets, the circuits used to meet the requirements, and a comparison of the theoretical and actual data will be presented
Development of an abort gap monitor for high-energy proton rings
The fill pattern in proton synchrotrons usually features an empty gap, longer than the abort kicker raise time, for machine protection. This gap is referred to as the "abort gap", and any particles, which may accumulate in it due to injection errors and diffusion between RF buckets, would be lost inside the ring, rather than in the beam dump, during the kicker firing. In large proton rings, due to the high energies involved, it is vital to monitor the build up of charges in the abort gap with a high sensitivity. We present a study of an abort gap monitor based on a photomultiplier with a gated microchannel plate, which would allow for detecting low charge densities by monitoring the synchrotron radiation emitted. We show results of beam test experiments at the Advanced Light Source using a Hamamatsu 5916U MCP-PMT and compare them to the specifications for the Large Hadron Collider.
Development of an Adder-Topology ILC Damping Ring Kicker Modulator
2009-05-08
The ILC damping ring injection and extraction kickers will require high availability modulators that can deliver {+-}5 kV pulses into 50 {Omega} with a 2 ns flattop ({approx}1 ns rise and fall time) at up to 6 MHz. An effort is underway at SLAC National Accelerator Laboratory to meet these requirements using a transmission line adder topology to combine the output of an array of {approx}1 kV modules. The modules employ an ultra-fast hybrid MOSFET/driver that can switch 33 A in 1.2 ns. Experimental results for a scale adder structure are presented.
Design and Development of Kickers and Septa for Medaustron
The MedAustron facility, to be built in Wiener Neustadt (Austria), will provide protons and ions for both cancer therapy and research. Different types of bumpers, septa and kickers will be used in the low energy beam transfer line, the synchrotron and the high energy extraction lines.They are presently being designed in collaboration with CERN. Both 2D and 3D finite element simulations have been carried out to verify and optimize the field strength and homogeneity for each type of magnet and, where applicable, the transient field response. The detailed designs for the injection and dump bumpers, the magnetic septa and the fast chopper dipoles are presented. A novel design for the electrostatic septa is outlined.
Beam Induced Heating of the SPS Fast Pulsed Magnets
Fast pulsed magnets with ferrite yokes are used in CERN's SPS accelerator for beam injection, extraction and excitation for tune measurements. The impedance of the ferrite structures can provoke significant beam induced heating, especially for beams with high peak currents as for LHC operation, even beyond the Curie temperature. The expected heating in the different kicker systems for various operational modes is compared with beam measurements. Estimates of the beam induced power have been derived from measured beam spectra. A fast extraction kicker system has recently been equipped with a cooling system. The measured cooling performance is compared with data from laboratory set-ups and numerical simulations.
1992-06-01
The Superconducting Super Collider`s Medium Energy Booster Abort (MEBA) kicker modulator will supply a current pulse to the abort magnets which deflect the proton beam from the MEB ring into a designated beam stop. The abort kicker will be used extensively during testing of the Low Energy Booster (LEB) and the MEB rings. When the Collider is in full operation, the MEBA kicker modulator will abort the MEB beam in the event of a malfunction during the filling process. The modulator must generate a 14-{mu}s wide pulse with a rise time of less than 1 {mu}s, including the delay and jitter times. It must also be able to deliver a current pulse to the magnet proportional to the beam energy at any time during ramp-up of the accelerator. Tracking the beam energy, which increases from 12 GeV at injection to 200 GeV at extraction, requires the modulator to operate over a wide range of voltages (4 kV to 80 kV). A vacuum spark gap and a thyratron have been chosen for test and evaluation as candidate switches for the abort modulator. Modulator design, switching time delay, jitter and pre-fire data are presented.
Design of kicker/bumper magnet and PFN for
1990-12-31
Three fast Pulsed kicker/bumper magnets are required in the positron accumulator ring (PAR) for the purpose of beam injection and/or extraction at 450 MeV. According to the Conceptual Design Report (CDR), these three magnets have, identical specifications and are expected to produce identical magnetic fields. Therefore, they will have the same design. Each kicker/bumper magnet is required to generate a magnetic field of 0.06 T with a rise time of 65 ns, a flat top of 80 ns and a fall time of 90 ns, respectively. A fast pulsed magnet system normally consists of a high voltage dc power supply, charging/discharging switches which are tetrodes and thyratrons in most cases, a pulse forming network (PFN), a magnet assembly consisting of a ferrite magnet, a matching capacitor or capacitors and a load (termination) resistor. The primary objective of this study is the design of the pulse forming network and magnet assembly.
Anabolic-androgenic steroids and brain reward.
Anabolic-androgenic steroid (AAS) effects on brain reward were investigated in male rats with electrodes implanted in the lateral hypothalamus using the rate-frequency curve shift paradigm of brain stimulation reward. In the first experiment, treatment for 2 weeks with the AAS methandrostenolone had no effect on either the reward or performance components of intracranial self-stimulation. In the second experiment, treatment for 15 weeks with an AAS "cocktail" consisting of testosterone cypionate, nandrolone decanoate, and boldenone undecylenate did not alter brain reward but did produce a slight but significant change in bar press rate. In addition to the AAS treatment, animals in the second study were administered a single injection of d-amphetamine before and after 15 weeks of AAS exposure. The rate-frequency curve shift observed in response to a systemic injection of amphetamine was significantly greater in animals after 15 weeks of treatment with the AAS cocktail. Although AAS do not appear to alter the rewarding properties of brain stimulation, AAS may influence the sensitivity of brain reward systems.
Injection Control System of HLS Storage Ring
2001-11-23
The injection control system of Hefei Light Source (HLS) storage ring is a subsystem of the upgraded HLS control system, which is based upon EPICS. Three programmable logic controllers (PLCs) are used as device controllers, which control one septum modulator and four kicker modulators of HLS storage ring. An Industrial PC is used as Input/Output Controller (IOC) and it connects the PLCs with serial communication (RS232 mode) over fibre. A PC with Linux is used as operator interface (OPI), operator application are running on it. The control system was completed in July 2000. The commissioning shows that the control system is reliable and easy operational.
2008-01-01
The DAPHINE PHI-factory at INFN-LNF has been upgraded in the second half of 2007 with the scope of testing a recently proposed scheme of crab waist collisions. New vacuum chambers and permanent quadrupole magnets have been designed, fabricated and installed to realize the new configuration. The ring injection systems have been also modified with the installation of new stripline fast injection kickers. Moreover the old bellows have been substituted by the new ones and all ion clearing electrodes in the electron ring have been removed. In the talk we describe the new layout as well as several experimental results obtained during the new run
2008-01-01
The DANE -factory at INFN-LNF has been upgraded in the second half of 2007 with the scope of testing a recently proposed scheme of crab waist collisions. New vacuum chambers and permanent quadrupole magnets have been designed, fabricated and installed to realize the new configuration. The ring injection systems have been also modified with the installation of new stripline fast injection kickers. Moreover the old bellows have been substituted by the new ones and all ion clearing electrodes in the electron ring have been removed. In the talk we describe the new layout as well as several experimental results obtained during the new run.
The DA?NE ?-factory at INFN-LNF has been upgraded in the second half of 2007 with the scope of testing a recently proposed scheme of crab waist collisions. New vacuum chambers and permanent quadrupole magnets have been designed, fabricated and installed to realize the new configuration. The ring injection systems have been also modified with the installation of new stripline fast injection kickers. Moreover the old bellows have been substituted by the new ones and all ion clearing electrodes in the electron ring have been removed. In the talk we describe the new layout as well as several experimental results obtained during the new run.
Injection septum magnets for the Loma Linda medical accelerator
The injection beamline runs over the last magnet before a long straight section and is then displaced downward 55.88 cm to the accelerator beamline. The displacement is magnetic and the final deflection onto the synchrotron orbit is by an electric kicker. The first component, the reverse septum magnet, bends the injection beam 25)degree) downward. This is followed by the injection septum (20)degree) bend upward) and the final injection kicker (5)degree) bend upward). The septum magnets produce a peak field of 3.4 K gauss at a current of 28,000 amperes within a 0.1 msec long pulse. The electric kicker produces a field of 7.3 KV/cm with a pulse length of 0.0011 msec. The septum magnets are similar to each other in construction with a bending radium of 72.7 cm. The curvature is required to increase the effective aperture. Each magnet has a single-turn copper coil bonded to a stainless steel plate for reinforcement. This eliminates insulating material, which could be subject to radiation damage, at the septum. The stainless steel plate is welded to the magnet laminations. The current is confined to the septum by the insulation between the laminations, which are a standard core material. The total septum thickness with shield is 1.227 cm. Pulsing the magnet eliminates the need for water cooling. 2 refs., 4 figs.
Injection septum magnets for the Loma Linda medical accelerator
1987-09-22
The injection beamline runs over the last magnet before a long straight section and is then displaced downward 55.88 cm to the accelerator beamline. The displacement is magnetic and the final deflection onto the synchrotron orbit is by an electric kicker. The first component, the reverse septum magnet, bends the injection beam 25)degree) downward. This is followed by the injection septum (20)degree) bend upward) and the final injection kicker (5)degree) bend upward). The septum magnets produce a peak field of 3.4 K gauss at a current of 28,000 amperes within a 0.1 msec long pulse. The electric kicker produces a field of 7.3 KV/cm with a pulse length of 0.0011 msec. The septum magnets are similar to each other in construction with a bending radium of 72.7 cm. The curvature is required to increase the effective aperture. Each magnet has a single-turn copper coil bonded to a stainless steel plate for reinforcement. This eliminates insulating material, which could be subject to radiation damage, at the septum. The stainless steel plate is welded to the magnet laminations. The current is confined to the septum by the insulation between the laminations, which are a standard core material. The total septum thickness with shield is 1.227 cm. Pulsing the magnet eliminates the need for water cooling. 2 refs., 4 figs.
AN INJECTION/EXTRACTION SCENARIO FOR EMMA
2009-01-01
EMMA is an experiment to study beam dynamics in a linear non-scaling fixed-field alternating gradient accelerator (FFAG). It accelerates an electron beam from 10 to 20 MeV kinetic energy. To optimally perform these studies, one must be able to inject the beam at any energy within the machine's energy range. Furthermore, because we wish to study the behavior of large-emittance beams in such a machine, the injection systems must be able to inject the beam anywhere within a transverse phase space ellipse with a normalized acceptance of 3 mm, and the extraction systems must be able to extract from that same ellipse. I describe a computation of kicker and septum fields to achieve all of these requirements, and discuss how this interacts with the hardware constraints
Acrylamide: induction of heritable translocations in male mice
Acrylamide (AA), known to induce dominant lethals in male rodents, was studied in the mouse heritable translocation test by using intraperitoneal injections on 5 consecutive days. Matings on days 7-10 following the last injection yielded a high frequency of translocation carriers in the F/sub 1/ male population, which demonstrated that acrylamide is an effective inducer of translocations in postmeiotic germ cells. As an inducer of both dominant lethals and heritable translocations in late spermatids and early spermatozoa, AA is similar to alkylating agents such as ethylmethanesulfonate and ethylene oxide. However, AA's chemical structure, the nature of adducts formed with DNA, and its lack of mutagenicity in bacteria suggest a different mechanism as the basis for AA's germ cell mutagenicity.
Acrylamide: induction of heritable translocations in male mice
1987-01-01
Acrylamide (AA), known to induce dominant lethals in male rodents, was studied in the mouse heritable translocation test by using intraperitoneal injections on 5 consecutive days. Matings on days 7-10 following the last injection yielded a high frequency of translocation carriers in the F/sub 1/ male population, which demonstrated that acrylamide is an effective inducer of translocations in postmeiotic germ cells. As an inducer of both dominant lethals and heritable translocations in late spermatids and early spermatozoa, AA is similar to alkylating agents such as ethylmethanesulfonate and ethylene oxide. However, AA's chemical structure, the nature of adducts formed with DNA, and its lack of mutagenicity in bacteria suggest a different mechanism as the basis for AA's germ cell mutagenicity.
The Beam Energy Tracking System of the LHC Beam Dumping System
The LHC Beam Dumping System (LBDS) of the Large Hadron Collider (LHC), presently under construction at CERN, will be installed around the straight section 6. It comprises per ring 15 horizontally deflecting extraction kickers, followed by 1 quadrupole, 15 vertically deflecting steel septum magnets, 10 dilution kickers and, in a separate cavern several hundred meters away, an external absorber assembly. A beam dump request can occur at any moment during the operation of the collider, from injection at 450 GeV up to top energy at 7 TeV. The Beam Energy Tracking System (BETS) monitors the deflection strength of each active element of the LBDS with respect to the beam energy in order to guarantee the correct extraction trajectory over the complete operational range and under all operational conditions. Its main functions are the acquisition of the beam energy, the generation of the kick strength reference signals for the extraction and dilution kickers, the continuous checking that the kicker high voltage generator capacitor charging voltages follow their references within predefined tolerance windows fixed by the extraction channel aperture, the continuous surveillance that the quadrupole and septum magnet currents are within predefined tolerance windows and the generation of a dump request after detection of and upcoming tracking fault. The beam energy reference is obtained through look-up tables from redundant real time measurements of the current in the LHC main bend dipoles. This paper describes the BETS reviews in detail its different functionality aspects.
METALLIZATION OF SNS RING INJECTION KICKER CERAMIC CHAMBERS.
Ceramic chambers will be used in the pulsed kicker magnets for the injection of H{sup -} into the Spallation Neutron Source (SNS) accumulator ring, to avoid shielding of a fast-changing external magnetic field by metallic chamber walls and to reduce eddy current heating. The inner surfaces of the ceramic chambers will be coated with a conductive layer, possibly titanium (Ti) or copper (Cu) with a titanium nitride (TiN) overlayer, to reduce the beam coupling impedance, provide passage for beam image current and to reduce the secondary electron yields. This paper describes the development of sputtering method for the 0.83m long 16cm inner diameter (ID) ceramic chambers. Coatings of Ti, Cu and TiN with thickness up to 10 {micro}m were produced by means of DC magnetron sputtering. The difficulty of coating insulators was overcome with the introduction of an anode screen. Films with good adhesion, uniform longitudinal thickness, and conductivity were produced.
METALLIZATION OF SNS RING INJECTION KICKER CERAMIC CHAMBERS.
2002-06-03
Ceramic chambers will be used in the pulsed kicker magnets for the injection of H{sup -} into the Spallation Neutron Source (SNS) accumulator ring, to avoid shielding of a fast-changing external magnetic field by metallic chamber walls and to reduce eddy current heating. The inner surfaces of the ceramic chambers will be coated with a conductive layer, possibly titanium (Ti) or copper (Cu) with a titanium nitride (TiN) overlayer, to reduce the beam coupling impedance, provide passage for beam image current and to reduce the secondary electron yields. This paper describes the development of sputtering method for the 0.83m long 16cm inner diameter (ID) ceramic chambers. Coatings of Ti, Cu and TiN with thickness up to 10 {micro}m were produced by means of DC magnetron sputtering. The difficulty of coating insulators was overcome with the introduction of an anode screen. Films with good adhesion, uniform longitudinal thickness, and conductivity were produced.
1400, +/- 900V PEAK PULSE SWITCH MODE POWER SUPPLIES FOR SNS INJECTION KICKERS
2004-01-01
This paper describes simulation and experimental results for a 1400A, +- 900V peak rated, switch mode power supply for SNS Injection Kicker Magnets. For each magnet (13 m(Omega), 160(micro)H), the power supply must supply controlled pulses at 60 Hz repetition rate. The pulse current must rise from zero to maximum in less than 1 millisec in a controlled manner, flat top for up to 2 millisec, and should fall in a controlled manner to less than 4A within 500(micro)s. The low current performance during fall time is the biggest challenge in this power supply. The simulation results show that to meet the controlled fall of the current and the current ripple requirements, voltage loop bandwidth of at least 10 kHz and switching frequency of at least 100 kHz are required. To achieve high power high frequency switching with IGBT switches, a series connected topology with three phase ...
1998-09-11
The Advanced Photon Source (APS) has a thermionic-cathode rf gun system capable of providing beam to the APS linac. The gun system consists of a 1.6-cell thermionic-cathode rf gun, a fast kicker for beam current control, and an alpha magnet for bunch compression and injection into the APS linac line. This system is intended for use both as an injector for positron creation, and as a first beam source for the Low-Energy Undulator Test Line (LEUTL) project [1]. The first measured performance characteristics of the gun are presented.
Lattice design for an ILC damping ring with 3 km circumference
2004-10-11
We describe a simple lattice that meets the specifications for the damping times and horizontal and longitudinal emittances for the International Linear Collider (ILC) damping rings. The circumference of a little over 3 km leads to a bunch spacing of around 3 ns, which will require advances in kicker technology for injection and extraction. We present the lattice design, and initial results of studies of the acceptance and collective effects. With the high bunch charge and close spacing, the ion and electron cloud effects are expected to be severe; however, the simple structure of the lattice allows for easy variation of the circumference and bunch spacing, which may make it useful for future investigations.
LHC Abort Gap Cleaning with the Transverse Damper
In the Large Hadron Collider, LHC, particles not captured by the RF system at injection or leaking out of the RF bucket may quench the superconducting magnets during beam abort. The problem, common to other superconducting machines, is particularly serious for the LHC due to the very large stored energy in the beam. For the LHC a way of removing the unbunched beam has been studied and it uses the existing damper kickers to excite resonantly the particles travelling along the abort gap. In this paper we describe the results of simulations performed with MAD X for various LHC optics configurations, including the estimated multipolar errors.
Dynamic Aperture Measurements at the Advanced Light Source
A large dynamic aperture for a storage ring is of importance for long lifetimes and a high injection efficiency. Measurements of the dynamic aperture of the third generation synchrotron light source Advanced Light Source (ALS) using beam excitation with kicker magnets are presented. The experiments were done for various accelerator conditions, allowing us to investigate the influence of different working points, chromaticities, insertion devices, etc.. The results are compared both with tracking calculations and a simple model for the dynamic aperture yielding good agreements. This gives us confidence in the predictability of the nonlinear accelerator model. This is especially important for future ALS upgrades as well as new storage ring designs.
Dynamic Aperture Measurements at the Advanced Light Source
A large dynamic aperture for a storage ring is of importance for long lifetimes and a high injection efficiency. Measurements of the dynamic aperture of the third generation synchrotron light source Advanced Light Source (ALS) using beam excitation with kicker magnets are presented. The experiments were done for various accelerator conditions, allowing us to investigate the influence of different working points, chromaticities, insertion devices, etc.. The results are compared both with tracking calculations and a simple model for the dynamic aperture yielding good agreements. This gives us confidence in the predictability of the nonlinear accelerator model. This is especially important for future ALS upgrades as well as new storage ring designs.
Dynamic Aperture Measurements at the Advanced Light Source
1999-03-12
A large dynamic aperture for a storage ring is of importance for long lifetimes and a high injection efficiency. Measurements of the dynamic aperture of the third generation synchrotron light source Advanced Light Source (ALS) using beam excitation with kicker magnets are presented. The experiments were done for various accelerator conditions, allowing us to investigate the influence of different working points, chromaticities, insertion devices, etc.. The results are compared both with tracking calculations and a simple model for the dynamic aperture yielding good agreements. This gives us confidence in the predictability of the nonlinear accelerator model. This is especially important for future ALS upgrades as well as new storage ring designs.
BEAM EXTRACTION FROM THE SNS RING AND DESIGN OF EXTRACTION KICKERS.
The accumulator ring of the Spallation Neutron Source (SNS) [1] will accumulate a proton beam, injected from a LINAC, into a single bunch containing {approximately} 2.1 x 10{sup 14} protons at a maximum energy of 1.3 GeV. The single bunch with length {approximately}650 nsec and a gap of {approximately}290 nsec will circulate into the accumulator ring for {approximately}1.0 msec before it is extracted into the RTBT transfer line. The accumulation, extraction frequency is set at 60 Hz. This paper discusses the extraction process and the requirements of the fast beam extraction system.
BEAM EXTRACTION FROM THE SNS RING AND DESIGN OF EXTRACTION KICKERS.
2000-06-30
The accumulator ring of the Spallation Neutron Source (SNS) [1] will accumulate a proton beam, injected from a LINAC, into a single bunch containing {approximately} 2.1 x 10{sup 14} protons at a maximum energy of 1.3 GeV. The single bunch with length {approximately}650 nsec and a gap of {approximately}290 nsec will circulate into the accumulator ring for {approximately}1.0 msec before it is extracted into the RTBT transfer line. The accumulation, extraction frequency is set at 60 Hz. This paper discusses the extraction process and the requirements of the fast beam extraction system.
Specification for Dump Bumper, Injection Bumper, Chopper Dipole and Tune Kicker Magnets
A synchrotron machine, capable to accelerate either light ions or protons, will be the basic instrument of the CNA (Centro Nazionale di Adroterapia), the medical center dedicated to the cancer therapy, that will be built in Italy in the near future. The machine complex consists of one proton-carbon-ion linac that will accelerate the particles till the energy of 7 MeV/u. An injection line will transport them to the synchrotron ring where the injected particles will be accelerated and extracted with an energy ranging from 60 to 250 MeV for protons and from 120 to 400 MeV/u for carbon ions. Fig. 1 shows a preliminary schematic picture of the CNA medical center.
Injection/Extraction Studies for the Muon FFAG
2010-01-01
The non-scaling fixed field alternating gradient (NS-FFAG) ring is a candidate muon accelerator in the Neutrino Factory complex according to the present baseline, which is currently being addressed by the International Design Study (IDS-NF). In order to achieve small orbit excursion, motivated by magnet cost reduction, and small time of flight variation, dictated by the need to use high RF frequency, lattices with a very compact cell structure and short straight sections are required. The resulting geometry dictates very difficult constraints on the injection/extraction systems. Beam dynamics in the non-scaling FFAG is studied using codes capable of correctly tracking with large transverse amplitude and momentum spread. The feasibility of injection/extraction is studied and various implementations focusing on minimization of kicker/septum strength are ...
Beam Commissioning of the Injection Protection System of the LHC
The movable LHC injection protection devices in the SPS-to-LHC transfer lines and downstream of the injection kicker in the LHC were commissioned with low-intensity beam. The different beam-based alignment measurements used to determine the beam centre and size are described, together with the results of measurements of the transverse beam distribution at large amplitude. The system was set up with beam to its nominal settings and the protection level against various failures was determined by measuring the transmission and transverse distribution into the LHC. Beam loss levels for regular operation were also extrapolated. The results are compared with the expected device settings and protection level, and the implications for LHC operation discussed.
An IGBT Driven Slotted Beam Pipe Kicker for SPEAR III Injection
2002-08-21
The SPEAR III injection kicker system is composed of three kicker magnets, K1, K2, and K3. These magnets, along with the power modulators to drive them constitute an injection system which will be used to deflect an incoming electron beam with an energy of 3.3 GeV by an angle of 2.5 mrad for K1 and K3, and 1 mrad for K2. The pulse shape of the magnetic field in the three magnets must be matched in order to preserve a closed orbit. The pulse duration is required to be less than 780 ns, with rise and fall times of less than 375 ns, and a pulse repetition frequency of 10 Hz. The aperture of all three magnets is 60 x 34 mm in an 8 inch vacuum vessel. The magnetic length is 1.2 m for K1 and K3, and 0.6 m for K2 [1]. The magnet design employs a slotted beam pipe which is shorted at one end. A solid state IGBT based, induction type of modulator drives the magnets. Modulators for K1 and K3 consist of eight 4.5 kV, 600 A IGBTs, and eight Finemet magnet cores with four 22.5 Ohm output cables to drive 2381 A into the magnets. The modulator for K2 uses four IGBTs and cores, and 8 output cables to produce a 2619 A pulse. Cables of length greater than one half the pulse width must be used in order to avoid reflections from the shorted magnet. The design charge voltage for the modulators is 20 kV for K1 and K3. This paper describes the magnet and modulator design, as and presents test data from a prototype system.
AGS new fast extraction system and the single bunch extraction test
1983-01-01
For the neutrino physics program and for the CBA injection, a new fast extraction system has been implemented to improve the extraction efficiency and the quality of the extracted beam. Central to the new system is a new fast kicker, placed at the H5 straight section, capable of rising between bunches, t/sub r/ < 170 nsec, and staying constant for 2.6 ..mu..sec with flat top ripple less than +-1.5%. So far, the system has been operated for longer than 3000 hours and routinely extracts 10/sup 13/ ppp at 99% efficiency. Experiment 745 on QCD test requires a single AGS bunch of 40 nsec. For this purpose another fast kicker was placed at the E5 straight section and powered by a new pulser to produce a half sinusoidal pulse with both a rise and fall time of 200 nsec. A single AGS bunch was extracted through the slow beam channel at 22 GeV/c leaving the remaining 11 bunches undisturbed which continued to be accelerated to 29.4 GeV/c and extracted by the H5 kicker through the fast beam channel. Because the ring circumference ratio of CBA to the AGS is 4-3/4, some of the injected beam from the AGS has to contain 11 bunches instead of 12; consequently, this single bunch extraction mode will also be used for CBA injection.
Acanthomatous ameloblastoma in dogs treated with intralesional bleomycin
2010-01-01
Acanthomatous ameloblastoma (AA) is a benign gingival tumour that often invades bone. This retrospective study evaluated the efficacy of intralesional (IL) bleomycin as a treatment for AA. Six dogs received weekly or bimonthly IL bleomycin injections (dose range, 10-20 U m-2). A seventh dog presented with advanced, nonresectable AA was treated palliatively. One to sixteen treatments were administered (median, 5). Six of the seven dogs had a complete response within 4 months from initial IL injection (median, 1.5 months), whereas the palliative case had approximately 25% decrease in tumour volume 14 days from initial injection. Local recurrence was not observed during the study period, with a median follow-up time of 842 days. Adverse effects were limited to wound formation with bone exposu...
Inactivation of channel catfish CYP1A by 2-aminoanthracene
1995-12-31
In {beta}NF-induced channel catfish, hepatic ethoxyresorufin-O-deethylase (EROD) activity decreased 66% 24 hours after injection of 2-aminoanthracene (AA, 10 mg/kg) compared with non-AA injected animals (p=0.001). This difference in hepatic EROD activity was also significant 48 hours after treatment (p = 0.001), but no significant difference was observed after 4 or 7 days. Immunoblot analysis of hepatic microsomal protein from fish 24 hours after treatment with AA revealed two bands crossreacting with CYP1A specific monoclonal antibody 1-12-3, an apparently native CYP1A protein (52 kDa) and a 30 kDa protein. Furthermore, these two proteins were preferentially bound by 3 H-AA compared with other microsomal proteins. Interestingly, the 30 kDa protein was observed only in fish exposed to AA and was immunoprecipitable with 1-12-3. In a separate in vivo experiment, hepatic EROD activity decreased and the 30 kDa protein increased with increased dose of AA. The 30 kDa protein is thought to be a CYP1A degradation product. In vitro experiments helped elucidate the mechanisms of interaction between AA and CYP1A Incubation of microsomes with AA, prior to analysis of these microsomes for EROD activity, resulted in a NADPH-dependent and-time-dependent inhibition of EROD activity. Additionally, the P450 inhibitors 1-phenylimidazole and 3,3{prime},4,4{prime}-tetrachlorobiphenyl were used to decrease the binding of AA to CYP1A, suggesting that the binding of AA to CYP1A requires the enzymatic activity of CYP1A. It is proposed that mechanism-based inactivation of CYP1A by AA accounts for the observed AA-dependent decrease in hepatic EROD activity in vitro and in vivo in channel catfish. The nature of the 30 kDa protein, including the AA-binding site(s), is under investigation.
Flame Furnace Atomic Absorption Spectrometry: A Review
2009-01-01
Flame atomic absorption spectrometry (FAAS) is one of the most widespread traditional analytical techniques for trace element determination, but it often suffers from poor sensitivity due to the low nebulization efficiency and the short residence time of free atoms in the flame. On the basis of conventional FAAS, flame furnace atomic absorption spectrometry (FF-AAS) is developed with a tube (flame furnace) placed on top of the FAAS burner for the atomization. Sample is introduced via beam injection (BIFF-AAS) or thermospray (TS-FF-AAS). Due to the total sample introduction and prolonged residence time of free atoms in the flame furnace, marked sensitivity improvement is obtained for volatile and semivolatile elements over conventional FAAS. TS-FF-AAS can be employed as an element-selective...
First circulating beam in the AA
1980-07-01
On 3 July 1980, two years after project authorization, beam circulated for the first time in the AA. It was a 3.56 GeV/c proton test beam. We see an expecting crowd, minutes before the happy event. The persons are too numerous to name them all, but the 3 most prominent ones are at the centre (left to right): Roy Billinge (Joint AA Project Leader, with his hand on the control box), Eifionydd Jones (white shirt), Simon van der Meer (spiritus rector and Joint AA Project Leader). The first antiprotons were injected, made to circulate and cooled soon after, on 14 July 1980.
2005-01-01
Background. Aristolochic acid (AA), the plant extract of Aristolochia species, is involved in the onset of progressive tubulointerstitial renal fibrosis in humans. Clinical and in vitro findings have previously suggested that the proximal tubule was the target of AA. Methods. Using a rat model of AA nephropathy, the proximal tubular lesions induced by daily subcutaneous injections of AA for 35 or 5 days were characterized biochemically and histologically. Urinary excretion of proteins, albumin, low molecular weight proteins, N-acetyl-b-d-glucosaminidase, a-glutathione S-transferase, leucine aminopeptidase and neutral endopeptidase (NEP) was determined and related to histological conventional findings and immunostainings of NEP and megalin. Results. In both protocols, an acute phase of rele...
2010-01-01
A reliable method for the determination of total vitamin C must be able to resolve ascorbic acid (AA) and the epimeric isoascorbic acid (IAA) and determine the sum of AA and its oxidized form dehydroascorbic acid. AA and IAA are polar molecules with a low retention time in conventional reversed phase systems, and hence of difficult resolution. Hydrophilic interaction chromatography using a TSKgel Amide-80 stationary phase with isocratic elution was successful in resolving the two epimers. The column was compatible with injections of high concentrations of metaphosphoric acid, tris(2-carboxyethyl)-phosphine, and EDTA without drift of baseline and retention time. Total AA and IAA were extracted, stabilized, and reduced in one step at 40C, using 5% m-phosphoric acid, 2mM of EDTA, and 2...
At the APS Retreat in May 2002, G. Rosenbaum proposed a method for increasing the effective vertical emittance of the APS beam. His proposal, illustrated in Figure 1, is to use a rapidly-modulated four-magnet vertical position bump in a single straight section. The proposed modulation frequency is a 10-kHz triangle wave, with a kick angle of 0.65 mrad. There are several aspects of this proposal that may be problematical: (1) The high modulation frequency will require the use of a ceramic chamber with a thin conductive coating, similar to what is used for the injection kicker magnets. This is not necessarily a problem, but the following aspects need to be examined: (a) The chamber coating needs to be specified correctly to ensure that the beam motion reflects the desired triangle-wave pattern. (b) The effect of the eddy currents in the chamber on the multipole content of the magnetic field needs to be computed, to ensure that the system does not have undesirable effects on the beam. (2) The magnets and their chambers will require careful matching in order to ensure that the beam is not disturbed outside of the bump. We know from experience with the APS kickers that this can be difficult. These issues are examined in the remainder of this note. The magnet and power supply designs are beyond our scope. We simply point out that these will not be conventional magnets or power supplies. The magnets will almost certainly need to be of ferrite construction, similar to the injection kickers. The power supplies will be unique and unlike anything else in the APS ring.
Quadrupolar Transverse Impedance of Simple Models of Kickers
The SPS kickers are major contributors to the SPS transverse beam coupling impedance. The current flat chamber impedance model for a kicker is obtained by applying form factors to the theoretical impedance of an axisymmetric ferrite beam pipe. This model was believed to be acceptable for the vertical dipolar impedance, as twowire measurements on SPS kickers revealed a satisfactory agreement. However, one-wire measurements on PS kickers suggested that this model underestimates the kickers transverse quadrupolar (detuning) impedance. The longitudinal and transverse dipolar impedances of another kicker model that accounts for the metallic plates on each side of the ferrite were derived in the past by H. Tsutsui. The same formalism is used in this paper to derive the quadrupolar impedance. These formulae were then successfully benchmarked to electromagnetic (EM) simulations. Finally, simulating the interaction of an SPS bunch with the improved kickers model results in a positive horizontal tune shift, which is very close to the tune shift measured with the SPS beam.
CONSTRUCTION AND POWER TEST OF THE EXTRACTION KICKER MAGNET FOR SNS ACCUMULATOR RING
2005-01-01
Two extraction kicker magnet assemblies that contain seven individual pulsed magnet modules each will kick the proton beam vertically out of the SNS accumulator ring into the aperture of the extraction Lambertson septum magnet. The proton beam then travels to the 1.4 MW SNS target assembly. The 14 kicker magnets and major components of the kicker assembly have been fabricated in BNL. The inner surfaces of the kicker magnets were coated with TiN to reduce the secondary electron yield. All 14 PFN power supplies have been built, tested and delivered to OWL. Before final installation, a partial assembly of the kicker system with three kicker magnets was assembled to test the functions of each critical component in the system. In this paper we report the progress of the construction of the kicker components, the TIN coating of the magnets, the installation procedure of the magnets and the ...
Fast superconducting magnetic field switch
1995-12-31
The superconducting magnetic switch or fast kicker magnet is employed with an electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater than the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube. This produces an internal field which effects the direction of motion and of the electron stream or electron bunch. The switch can also operate as a switching mechanism for charged particles. Magnetic switches and particularly fast kicker magnets are used in the accelerator industry to quickly deflect particle beams into and out of various transport lines, storage rings, dumps, and specifically to differentially route individual bunches of particles from a train of bunches which are injected or ejected from a given ring.
Development of an abort gap monitor for high-energy proton rings
The fill pattern in proton synchrotrons usually features an empty gap, longer than the abort kicker raise time, for machine protection. This gap is referred to as the ''abort gap'' and any particles, which may accumulate in it due to injection errors and diffusion between RF buckets, would be lost inside the ring, rather than in the beam dump, during the kicker firing. In large proton rings, due to the high energies involved, it is vital to monitor the build up of charges in the abort gap with a high sensitivity. We present a study of an abort gap monitor based on a photomultiplier with a gated microchannel plate, which would allow for detecting low charge densities by monitoring the synchrotron radiation emitted. We show results of beam test experiments at the Advanced Light Source using a Hamamatsu 5916U MCP-PMT and compare them to the specifications for the Large Hadron Collider
Development of an abort gap monitor for high-energy proton rings
2004-05-03
The fill pattern in proton synchrotrons usually features an empty gap, longer than the abort kicker raise time, for machine protection. This gap is referred to as the ''abort gap'' and any particles, which may accumulate in it due to injection errors and diffusion between RF buckets, would be lost inside the ring, rather than in the beam dump, during the kicker firing. In large proton rings, due to the high energies involved, it is vital to monitor the build up of charges in the abort gap with a high sensitivity. We present a study of an abort gap monitor based on a photomultiplier with a gated microchannel plate, which would allow for detecting low charge densities by monitoring the synchrotron radiation emitted. We show results of beam test experiments at the Advanced Light Source using a Hamamatsu 5916U MCP-PMT and compare them to the specifications for the Large Hadron Collider
In a series of 3 experiments, adult male Long-Evans rats were castrated and treated with 1 of 3 different anabolic-androgenic steroid (AAS) compounds (17 alpha-methyltestosterone, methandrostenolone, or nandrolone decanoate) for 6 weeks. In each experiment, subjects received daily injections of a high, medium, or low dose of AAS or the oil vehicle. The AAS effects on body weight in gonadectomized male rats were modest, and no effects on locomotor activity were observed. The AAS compounds administered at doses comparable with human abuse levels were not equipotent in maintaining male sexual behavior patterns (nandrolone decanoate > methandrostenolone > 17 alpha-methyltestosterone). In addition, the behavioral actions of AAS compounds did not parallel stimulation of sexual accessory glands. The authors reported that this study is the first to quantify the dose-response characteristics of individual AAS compounds with regard to these behavioral and endocrine measures.
Status of the LHC proton beam in the CERN SPS
During the 2000-2001 shutdown the SPS has undergone a major hardware upgrade to cope with its role of LHC injector. An impedance reduction campaign, improvements to the RF beam-control systems, and modifications to the injection kicker magnets and transverse feedback were the main items of this upgrade. By the end of the 2001 run, after a series of machine development sessions, a single LHC batch with half the nominal intensity could be accelerated from 26 to 450 GeV/c, the LHC injection energy, with nominal longitudinal and transverse parameters. At present the major known obstacle to the achievement of the nominal LHC beam with four batches is the beam-induced electron cloud. This generates both dramatic vacuum pressure increases and fast single and coupled bunch transverse instabilities. The problems encountered with this high brilliance beam and solutions developed so far are presented. Possible cures for the existing limitations are outlined.
Specification for the power supply for tune kicker magnets of the synchrotron accelerator
A synchrotron machine, capable to accelerate either light ions or protons, will be the basic instrument of the CNA (Centro Nazionale di Adroterapia), the medical centre dedicated to the cancer therapy, that will be built in Italy in the near future. The machine complex consists of one proton-carbon-ion linac that will accelerate the particles up to an energy of 7 MeV/u. An injection line will transport them to the synchrotron ring where the injected particles will be accelerated and extracted with an energy ranging from 60 to 250 MeV for protons and from 120 to 400 MeV/u for carbon ions. Fig. 1 shows a preliminary schematic picture of the CNA medical centre.
2008-09-15
The DA{phi}NE {phi}-factory at INFN-LNF has been upgraded in the second half of 2007 with the scope of testing a recently proposed scheme of crab waist collisions. New vacuum chambers and permanent quadrupole magnets have been designed, fabricated and installed to realize the new configuration. The ring injection systems have been also modified with the installation of new stripline fast injection kickers. Moreover the old bellows have been substituted by the new ones and all ion clearing electrodes in the electron ring have been removed. In the talk we describe the new layout as well as several experimental results obtained during the new run.
BEAM TRANSPORT LINES FOR THE BSNS.
This paper presents the design of two beam transport lines at the BSNS: one is the injection line from the Linac to the RCS and the other is the target line from the RCS to the target station. In the injection beam line, space charge effects, transverse halo collimation, momentum tail collimation and debunching are the main concerned topics. A new method of using triplet cells and stripping foils is used to collimate transverse halo. A long straight section is reserved for the future upgrading linac and debuncher. In the target beam line, large halo emittance, beam stability at the target due to kicker failures and beam jitters, shielding of back-scattering neutrons from the target are main concerned topics. Special bi-gap magnets will be used to reduce beam losses in the collimators in front of the target.
BEAM TRANSPORT LINES FOR THE BSNS.
This paper presents the design of two beam transport lines at the BSNS: one is the injection line from the Linac to the RCS and the other is the target line from the RCS to the target station. In the injection beam line, space charge effects, transverse halo collimation, momentum tail collimation and debunching are the main concerned topics. A new method of using triplet cells and stripping foils is used to collimate transverse halo. A long straight section is reserved for the future upgrading linac and debuncher. In the target beam line, large halo emittance, beam stability at the target due to kicker failures and beam jitters, shielding of back-scattering neutrons from the target are main concerned topics. Special bi-gap magnets will be used to reduce beam losses in the collimators in front of the target.
BEAM TRANSPORT LINES FOR THE BSNS.
2006-06-26
This paper presents the design of two beam transport lines at the BSNS: one is the injection line from the Linac to the RCS and the other is the target line from the RCS to the target station. In the injection beam line, space charge effects, transverse halo collimation, momentum tail collimation and debunching are the main concerned topics. A new method of using triplet cells and stripping foils is used to collimate transverse halo. A long straight section is reserved for the future upgrading linac and debuncher. In the target beam line, large halo emittance, beam stability at the target due to kicker failures and beam jitters, shielding of back-scattering neutrons from the target are main concerned topics. Special bi-gap magnets will be used to reduce beam losses in the collimators in front of the target.
Acanthomatous ameloblastoma in dogs treated with intralesional bleomycin.
Acanthomatous ameloblastoma (AA) is a benign gingival tumour that often invades bone. This retrospective study evaluated the efficacy of intralesional (IL) bleomycin as a treatment for AA. Six dogs received weekly or bimonthly IL bleomycin injections (dose range, 10-20 U m(-2)). A seventh dog presented with advanced, nonresectable AA was treated palliatively. One to sixteen treatments were administered (median, 5). Six of the seven dogs had a complete response within 4 months from initial IL injection (median, 1.5 months), whereas the palliative case had approximately 25% decrease in tumour volume 14 days from initial injection. Local recurrence was not observed during the study period, with a median follow-up time of 842 days. Adverse effects were limited to wound formation with bone exposure (n = 4), mild tissue reactions (n = 3), local swelling (n = 2) and local infection (n = 1). The conclusions of this study show IL bleomycin is an effective treatment for canines with AA.
Impedance model of the CERN SPS and aspects of LHC single-bunch stability
Upgrades of the CERN particle accelerators complex are planned to increase the potential of physics discovery in the LHC. In this respect, the beam coupling impedances of the SPS and LHC are expected to be among the limitations to the intensity upgrade scheme. In this thesis work, we present a general framework to better understand the impedance of a particle accelerator. In a first step, the impedance of single components are gathered into an impedance model accounting for the whole machine. In order to assess the relevance of this impedance model, its impact on beam dynamics is simulated and can be compared to impedance observables measured with beam. This general framework was applied to compute a more accurate transverse impedance model of the SPS from theoretical models for the 20 kickers and the 6.9 km long beam pipe, as well as time domain electromagnetic simulations of the 106 horizontal and 96 vertical SPS beam position monitors. Comparing HEADTAIL macroparticle simulations to beam-based measurements in the SPS, this transverse impedance model turned out to account for 65% of the vertical impedance measured in the machine and showed in addition that the large negative quadrupolar horizontal impedance of the kickers can be held responsible for the measured positive coherent horizontal tune shift with increasing beam intensity. In the course of implementing this framework, new contributions were brought to the understand ing of impedances and wake fields. A more general formula was derived for the longitudinal impedance of a multilayer cylindrical beam pipe. New formulae for the transverse quadrupolar impedances of simple models of kickers were also derived and successfully benchmarked to electromagnetic simulations. In addition, MOSES mode coupling analytical calculations were successfully benchmarked against HEADTAIL macroparticle simulations in predicting a Transverse Mode Coupling Instability at injection in the SPS between azimuthal modes -2 and -3. Finally, new RF bench measurements validated the theory proposed by B. Zotter and E. Metral, thereby confirming that the low frequency transverse impedance of the LHC collimators , which largely dominates the LHC transverse impedance is less critical than initially expected.
1992-10-01
This paper discusses the coupled-bunch instability and how it applies to the ALS accelerator. The longitudinal ALS kicker is part of the bunch-to-bunch feedback system planned to control coupled-bunch instabilities in the ALS. The mechanical features of the kicker are described, and the analytic tools developed to aid in the design are discussed. A method to predict the performance of the kicker in the accelerator from measurements on a prototype are described.
1992-10-01
This paper discusses the coupled-bunch instability and how it applies to the ALS accelerator. The longitudinal ALS kicker is part of the bunch-to-bunch feedback system planned to control coupled-bunch instabilities in the ALS. The mechanical features of the kicker are described, and the analytic tools developed to aid in the design are discussed. A method to predict the performance of the kicker in the accelerator from measurements on a prototype are described.
1983-07-01
Immunologically mediated aplastic anemia (AA) was experimentally induced in mice by injecting 10(7) lymph node cells (LNC) from donor mice of one inbred strain to another H-2k identical but Mls mismatched strain previously given 600 rad total body gamma irradiation (TBI). AA developed after 2 weeks to 6 months in selected strain combinations used and usually 60 to 90% of the mice died. Clinical signs of graft-versus-host disease did not occur and splenic atrophy rather than splenomegaly was the rule. Histologically these mice had a lesion of the hematopoietic microenvironment characterized by sinusoidal injury and stromal necrosis. Others have demonstrated injury to hematopoietic stem cells. C3H/He LNC induced AA whereas C3H/HeJ LNC failed to induce AA. The C3H/HeJ strain carries a macrophage defect and these results suggest that a macrophage-like cell may be a mediator of immunological injury in this experimental model. Although all strain combinations evaluated were H-2k identical and Mls mismatched, certain Mls combinations resulted in AA and identical Mls mismatched but different strains did not. Both strong (Mlsd) and weak (Mlsc) stimulating LNC induce AA but simple Mls differences do not explain the AA as similar Mls combinations but different strain combinations fail to induce AA.
SNS EXTRACTION KICKER SYSTEM AND FIRST ARTICLE BPFN TEST.
The Spallation Neutron Source (SNS) extraction kicker system brings the proton beam from the accumulator ring through a beam transfer line into the target area. The 14 kicker magnets are located in one straight section. The kicker magnets are energized by 14 Blumlein type Pulse Forming Networks (BPFN). The first article of the SNS extraction kicker BPFN was assembled and tested at this laboratory. This paper describes the kicker BPFN system arrangement and parameters. The first article BPFN design and its main components used are explained. High voltage BPFN test results and the load current waveform are illustrated in this paper. Temperature measurements of the kicker ferrite blocks at full power showed only small or no heating. This paper discusses the modifications to the BPFN design, such as a saturating inductor and 25 Q termination, to minimize the transverse coupling impedance.
SNS EXTRACTION KICKER SYSTEM AND FIRST ARTICLE BPFN TEST.
The Spallation Neutron Source (SNS) extraction kicker system brings the proton beam from the accumulator ring through a beam transfer line into the target area. The 14 kicker magnets are located in one straight section. The kicker magnets are energized by 14 Blumlein type Pulse Forming Networks (BPFN). The first article of the SNS extraction kicker BPFN was assembled and tested at this laboratory. This paper describes the kicker BPFN system arrangement and parameters. The first article BPFN design and its main components used are explained. High voltage BPFN test results and the load current waveform are illustrated in this paper. Temperature measurements of the kicker ferrite blocks at full power showed only small or no heating. This paper discusses the modifications to the BPFN design, such as a saturating inductor and 25 Q termination, to minimize the transverse coupling impedance.
SNS EXTRACTION KICKER SYSTEM AND FIRST ARTICLE BPFN TEST.
2002-06-03
The Spallation Neutron Source (SNS) extraction kicker system brings the proton beam from the accumulator ring through a beam transfer line into the target area. The 14 kicker magnets are located in one straight section. The kicker magnets are energized by 14 Blumlein type Pulse Forming Networks (BPFN). The first article of the SNS extraction kicker BPFN was assembled and tested at this laboratory. This paper describes the kicker BPFN system arrangement and parameters. The first article BPFN design and its main components used are explained. High voltage BPFN test results and the load current waveform are illustrated in this paper. Temperature measurements of the kicker ferrite blocks at full power showed only small or no heating. This paper discusses the modifications to the BPFN design, such as a saturating inductor and 25 Q termination, to minimize the transverse coupling impedance.
SNS EXTRACTION KICKER SYSTEM AND FIRST ARTICLE BPFN TEST
2002-01-01
The Spallation Neutron Source (SNS) extraction kicker system brings the proton beam from the accumulator ring through a beam transfer line into the target area. The 14 kicker magnets are located in one straight section. The kicker magnets are energized by 14 Blumlein type Pulse Forming Networks (BPFN). The first article of the SNS extraction kicker BPFN was assembled and tested at this laboratory. This paper describes the kicker BPFN system arrangement and parameters. The first article BPFN design and its main components used are explained. High voltage BPFN test results and the load current waveform are illustrated in this paper. Temperature measurements of the kicker ferrite blocks at full power showed only small or no heating. This paper discusses the modifications to the BPFN design, such as a saturating inductor and 25 Q termination, to minimize the transverse coupling ...
The bridged-T network lumped kicker: A novel fast magnetic kicker system for a compact synchrotron
2009-01-01
This study proposes a novel fast magnetic kicker system: the bridged-T network lumped kicker. The rise time is comparable with that of a transmission line kicker, while the input impedance can be matched with the characteristic impedance of the pulse power supply. A lumped magnet core and matching elements form the bridged-T network, so that the complex structure associated with a transmission line magnet is no longer required. The proposed scheme is compared with several conventional schemes. A demonstration of the proposed scheme is also performed and the results are as anticipated
The bridged-T network lumped kicker: A novel fast magnetic kicker system for a compact synchrotron
2009-01-01
This study proposes a novel fast magnetic kicker system: the bridged-T network lumped kicker. The rise time is comparable with that of a transmission line kicker, while the input impedance can be matched with the characteristic impedance of the pulse power supply. A lumped magnet core and matching elements form the bridged-T network, so that the complex structure associated with a transmission line magnet is no longer required. The proposed scheme is compared with several conventional schemes. A demonstration of the proposed scheme is also performed and the results are as anticipated.
Recycler short kicker beam impedance
Measured longitudinal and calculated transverse beam impedance is presented for the short kicker magnets being installed in the Fermilab Recycler. Fermi drawing number ME-457159. The longitudinal impedance was measured with a stretched wire and the Panofsky equation was used to estimate the transverse impedance. The impedance of 3319 meters (the Recycler circumference) of stainless vacuum pipe is provided for comparison. Although measurements where done to 3GHz, impedance was negligible above 30MHz. The beam power lost to the kicker impedance is shown for a range of bunch lengths. The measurements are for one kicker assuming a rotation frequency of 90KHz. Seven of these kickers are being installed.
Recycler short kicker beam impedance
Measured longitudinal and calculated transverse beam impedance is presented for the short kicker magnets being installed in the Fermilab Recycler. Fermi drawing number ME-457159. The longitudinal impedance was measured with a stretched wire and the Panofsky equation was used to estimate the transverse impedance. The impedance of 3319 meters (the Recycler circumference) of stainless vacuum pipe is provided for comparison. Although measurements where done to 3GHz, impedance was negligible above 30MHz. The beam power lost to the kicker impedance is shown for a range of bunch lengths. The measurements are for one kicker assuming a rotation frequency of 90KHz. Seven of these kickers are being installed.
Recycler short kicker beam impedance
2009-07-01
Measured longitudinal and calculated transverse beam impedance is presented for the short kicker magnets being installed in the Fermilab Recycler. Fermi drawing number ME-457159. The longitudinal impedance was measured with a stretched wire and the Panofsky equation was used to estimate the transverse impedance. The impedance of 3319 meters (the Recycler circumference) of stainless vacuum pipe is provided for comparison. Although measurements where done to 3GHz, impedance was negligible above 30MHz. The beam power lost to the kicker impedance is shown for a range of bunch lengths. The measurements are for one kicker assuming a rotation frequency of 90KHz. Seven of these kickers are being installed.
Low-coupling impedance double-helix structure for use in a ferrite kicker magnet
In a machine such as the CBA, the ejection ferrite kicker magnet has a very large longitudinal and transverse coupling impedance which could destroy the beam. Using a double-helix structure that surrounds the beam, the beam-induced fields are confined within the helix and, therefore, decoupled from the kicker; but at the same time the helix is transparent to the external fields of the kicker. At first, this may seem paradoxical that the helix is opaque to the fields generated inside the structure by the beam and simultaneously transparent to the external fields generated by the kicker.
Beam Commissioning and Performance Characterisation of the LHC Beam Dump Kicker Systems
The LHC beam dump system was commissioned with beam in 2009. This paper describes the operational experience with the kicker systems and the tests and measurements to qualify them for operation. The kicker performance was characterized with beam by measurements of the deflection angles, using bunches extracted at different times along the kicker sweep. The kicker performance was also continuously monitored for each dump with measurement and analysis of all kick pulses, allowing diagnostic of errors and of long-term drifts. The results are described and compared to the expectations.
Anabolic-androgenic steroid effects on the sexual behavior of intact male rats.
Six separate experiments were conducted which examined the effects of long-term administration of anabolic-androgenic steroid (AAS) compounds on the sexual behavior of gonadally intact male rats. The six AAS compounds analyzed in this study were 17alpha-methyltestosterone, methandrostenolone, nandrolone decanoate, stanozolol, oxymetholone, and testosterone cypionate. In each experiment, subjects received daily injections of a high, medium, or low dose of the AAS compound, or the oil vehicle, for 12 weeks. Sexual behavior was quantified weekly. Twelve weeks of administration of the high dose of three AAS compounds, 17alpha-methyltestosterone, stanozolol, and oxymetholone, eliminated male sexual behavior. These treatments also suppressed serum testosterone levels. The remaining compounds had minimal effects on sexual behavior at any dose. Thus, in intact male rats the six AAS compounds examined in these studies evoked a range of behavioral and endocrine responses that varied as a function of the specific compound and dose administered.
The Lambertson Septum Magnet of the Spallation Neutron Source
In the Spallation Neutron Source, at Oak Ridge National Laboratory in Tennessee, multiple-stage injections to an accumulator ring increase intensity until a final extraction delivers the full proton beam to the target via transfer line. This extraction is achieved by a series of kicker elements and a thin septum Extraction Lambertson Septum Magnet. Here we discuss the lattice geometry, beam dynamics and optics, and the vacuum, electromagnetic and electromechanical design aspects of the SNS Extraction Lambertson Septum Magnet. Relevant datums are established. Beam optics is studied. Vector calculus is solved for pitch and roll angles. Fundamental magnet sections are depicted schematically. Coil, pole and yoke design calculations and electromagnetics optimization are presented.
Performance of Advanced Light Source particle beam diagnostics
The Advanced Light Source (ALS), a third-generation synchrotron radiation facility, is complete. The particle beam diagnostics have been installed and tested. The beam injection systems have been running for two years. We have performance data on beam position monitors, beam intensity monitors, scintillators, beam collimators, a 50 {Omega} Faraday cup, and broad-band striplines and kickers used in the linac, transport lines, and the booster synchrotron. The single-turn monitoring capability of the booster beam position monitoring system has been particularly useful for studying beam dynamics. Beam diagnostics for the storage ring are being commissioned. In this paper we describe each instrument, show its performance, and outline how the instruments are controlled and their output data displayed.
Performance of Advanced Light Source particle beam diagnostics
1993-05-01
The Advanced Light Source (ALS), a third-generation synchrotron radiation facility, is complete. The particle beam diagnostics have been installed and tested. The beam injection systems have been running for two years. We have performance data on beam position monitors, beam intensity monitors, scintillators, beam collimators, a 50 {Omega} Faraday cup, and broad-band striplines and kickers used in the linac, transport lines, and the booster synchrotron. The single-turn monitoring capability of the booster beam position monitoring system has been particularly useful for studying beam dynamics. Beam diagnostics for the storage ring are being commissioned. In this paper we describe each instrument, show its performance, and outline how the instruments are controlled and their output data displayed.
Longitudinal Impedance Measurements of the Components for the BEPCII
A longitudinal impedance measurement system was established for the BEPCII. The measurements, done in the frequency domain, are based on the coaxial wire method using HP/Agilent 8720ES network analyzer. The applications of the TRL calibration technique and absorbers were investigated to find a good approach for impedance measurements. The impedance, larger than 20 Ohm and below 6 GHz, can be measured using the TRL calibration technique in the experiment. And better measurement results were got using the reference pipes with the absorbers. So, this system satisfies the requirements of the BEPCII. This paper gives a review on this impedance measurements system for the BEPCII. The measurements results show that there are no serious impedance problems for BEPCII bellows and injection kickers, agreeing well with the numerical simulations. More improvements on this system are in progress.
LASL high-current proton storage rings
The Proton Storage Ring at LAMPF is a high-current accumulator designed to convert long 800-MeV linac pulses into very short high-intensity proton bunches ideally suited to driving a pulsed polyenergetic neutron source. The Ring, authorized for construction at $19 million, will operate in a short-bunch high-frequency mode for fast neutron physics and a long-bunch low-frequency mode for thermal neutron-scattering programs. Unique features of the project include charge-changing injection with initial conversion from H/sup -/ to H/sup 0/, a high repetition rate fast-risetime extraction kicker, and high-frequency and first-harmonic bunching system.
LASL high-current proton storage rings
1980-01-01
The Proton Storage Ring at LAMPF is a high-current accumulator designed to convert long 800-MeV linac pulses into very short high-intensity proton bunches ideally suited to driving a pulsed polyenergetic neutron source. The Ring, authorized for construction at $19 million, will operate in a short-bunch high-frequency mode for fast neutron physics and a long-bunch low-frequency mode for thermal neutron-scattering programs. Unique features of the project include charge-changing injection with initial conversion from H/sup -/ to H/sup 0/, a high repetition rate fast-risetime extraction kicker, and high-frequency and first-harmonic bunching system.
The level of aromatase in the preoptic area of rats is transcriptionally regulated through a specific androgen-receptor mediated mechanism and can be used as a measure of central androgenic effect. Therefore, several commonly abused anabolic-androgenic steroids (AAS) were tested for their ability to induce aromatase activity in the preoptic area of castrated rats. In addition, we determined the relative binding affinities of these compounds for the androgen receptor, as well as their ability to bind androgen receptor in vivo following subcutaneous injections. All of the AAS compounds tested significantly stimulated POA aromatase activity above castrate levels. The compounds that produced the greatest stimulation of aromatase activity were those that bound most avidly to the androgen receptor in vitro (i.e., testosterone, dihydrotestosterone and nandrolone). In contrast, the 17alpha-alkylated compounds that were tested (stanozolol, danazol, methandrostenolone) modestly stimulated aromatase and were weak competitors for the androgen receptor. The subcutaneous injection of AAS compounds increased the concentrations of occupied nuclear androgen receptors in the brain, but the magnitude of effect was not related to their potency for inducing aromatase or their relative binding affinity for the androgen receptor suggesting that androgen receptor occupancy in POA is not correlated with the action of androgen on aromatase. The present results help explain the behavioral effects of AAS compounds in rats.
Self-interstitials and related defects in irradiated silicon
2009-01-01
Low intensity light ions (H+ or He++) irradiation of silicon introduced EPR Si-AA12 defect. Si-AA12 reveals close correlations with DLTS E1=Ec-0.39 eV minority trap. Impurity interstitials or self-interstitial associated secondary defects, such as interstitial carbon (Ci) or aluminum (Ali) or self-interstitial-oxygen complex (Sii-Oi), appear upon thermal annealing at 280-350 K and especially under injection at 77 K of Si-AA12 and E1 state. Strong 1:1 correlation between injection annealing of E1 and increasing Ci in FZ-Si and sum of (Sii-Oi)+Ci as well observed reversible transformation of Si-AA12 and E1 onto (Sii-Oi) and their re-emission after annealing (Sii-Oi) allow to ...
Effect of 4-aminoantipyrine on gastric compliance and liquid emptying in rats.
Dipyrone (Dp) delays gastric emptying (GE) in rats. There is no information about whether 4-aminoantipyrine (AA), one of its metabolites, has the same effect. The objectives of the present study were to assess the effects of AA and Dp on GE when administered intravenously (iv) and intracerebroventricularly (icv) (240 micromol/kg and 4 micromol/animal, respectively) and on gastric compliance when administered iv (240 micromol/kg). GE was determined in male Wistar rats weighing 250-300 g (5-10 per group) after icv or iv injection of the drug by measuring percent gastric retention (GR) of a saline meal labeled with phenol red 10 min after administration by gavage. Gastric compliance was estimated in anesthetized rats (10-11 per group), with the construction of volume-pressure curves during intragastric infusion of a saline meal. Compliance was significantly greater in animals receiving Dp (mean +/- SEM = 0.26 +/- 0.009 mL/mmHg) and AA (0.24 +/- 0.012 mL/mmHg) than in controls (0.19 +/- 0.009 mL/mmHg). AA and Dp administered iv significantly increased GR (64.4 +/- 2.5 and 54.3 +/- 3.8%, respectively) compared to control (34 +/- 2.2%), a phenomenon observed only with Dp after icv administration. Subdiaphragmatic vagotomy reduced the effect of AA (GR = 31.4 +/- 1.5%) compared to sham-treated animals. Baclofen, a GABAB receptor agonist, administered icv significantly reduced the effect of AA (GR = 28.1 +/- 1.3%). We conclude that Dp and AA increased gastric compliance and AA delayed GE, with the participation of the vagus nerve, through a pathway that does not involve a direct action of the drug on the central nervous system.
Two extraction kicker magnet assemblies that contain seven individual pulsed magnet modules each will kick the proton beam vertically out of the SNS accumulator ring into the aperture of the extraction lambertson septum magnet. The proton beam then travels to the 1.4 MW SNS target assembly. The 14 kicker magnets and major components of the kicker assembly have been fabricated in BNL. The inner surfaces of the kicker magnets were coated with TiN to reduce the secondary electron yield. All 14 PFN power supplies have been built, tested and delivered to ORNL. Before final installation, a partial assembly of the kicker system with three kicker magnets was assembled to test the functions of each critical component in the system. In this paper we report the progress of the construction of the kicker components, the TiN coating of the magnets, the installation procedure of the magnets and the full power test of the kicker with the PFN power supply.
CONSTRUCTION AND POWER TEST OF THE EXTRACTION KICKER MAGNET FOR SNS ACCUMULATOR RING.
2005-05-16
Two extraction kicker magnet assemblies that contain seven individual pulsed magnet modules each will kick the proton beam vertically out of the SNS accumulator ring into the aperture of the extraction Lambertson septum magnet. The proton beam then travels to the 1.4 MW SNS target assembly. The 14 kicker magnets and major components of the kicker assembly have been fabricated in BNL. The inner surfaces of the kicker magnets were coated with TiN to reduce the secondary electron yield. All 14 PFN power supplies have been built, tested and delivered to OWL. Before final installation, a partial assembly of the kicker system with three kicker magnets was assembled to test the functions of each critical component in the system. In this paper we report the progress of the construction of the kicker components, the TIN coating of the magnets, the installation procedure of the magnets and the full power test of the kicker with the PFN power supply.
A New CERN PS Transverse Damper
Since 1999 the PS has been operated without active transverse damping thanks to an increase of the coupling between the transverse planes and the reduction of injection steering errors. Although the LHC requirements are met by these means, a new transverse feedback system has been commissioned to reinforce the robustness of operation and avoid the blow-up generated by residual injection steering errors. This system could also allow the reduction of the chromaticity and reduce the slow incoherent losses during the long PS injection plateau. It could also stabilize the high energy instabilities that appear occasionally with the LHC nominal beam and may be a limiting factor for ultimate LHC beam. Highlights include a signal processing with an automatic delay adapting itself to the varying revolution frequency, a programmable betatron phase adjustment along the cycle, pick-ups that have been re-furbished with electronics covering the very low frequency of the first betatron line and a compact wideband high-power solid state amplifier that drives the stripline kicker via an impedance matching transformer. The overall system is described together with experimental results.
2005-01-01
The microcolumn of salen I (N,Nprime-bis (salicylidene) ethylenediamine) immobilized on surfactant-coated alumina has been used for on-line preconcentration of copper and lead with a flow injection-flame atomic absorption spectrometry (FI-AAS). Various parameters affecting the deposition/elution processes in the FI-AAS system was optimized. Deposition of analytes was affected at pH of 9, and injection of nitric acid (250ml 2moll-1) served to elute retained species to AAS. A good relative standard deviation of 4.5 and 3.8% at 30mg l-1(n=7), high enrichment factors of 100 and 75, and detection limits of 0.3, 2.6mgl-1 (3S) for Cu(II) and Pb(II) were obtained, respectively. The method was applied to water samples, multivitamin tablet and standard reference alloys (C12E41 and C12X3500) and accu...
2005-01-01
The microcolumn of salen I (N,N'-bis (salicylidene) ethylenediamine) immobilized on surfactant-coated alumina has been used for on-line preconcentration of copper and lead with a flow injection-flame atomic absorption spectrometry (FI-AAS). Various parameters affecting the deposition/elution processes in the FI-AAS system was optimized. Deposition of analytes was affected at pH of approx9, and injection of nitric acid (250 mul 2 mol l-1) served to elute retained species to AAS. A good relative standard deviation of 4.5 and 3.8% at 30 mug l-1(n = 7), high enrichment factors of 100 and 75, and detection limits of 0.3, 2.6 mug l-1 (3S) for Cu(II) and Pb(II) were obtained, respectively. The method was applied to water samples, multivitamin tablet and standard reference alloys (C12E41 ...
SNS EXTRACTION KICKER POWER SUPPLY PROTOTYPE TEST
2000-06-27
The SNS (Spallation Neutron Source) accumulator ring Extraction System consists of a Fast kicker and a Lambertson Septum magnet. The proposed design will use 14 kicker magnets powered by an Extraction Kicker Power Supply System. They will eject the high power beam from the SNS accumulator ring into RTBT (Ring to Target Beam Tunnel) through a Lambertson Septum magnet. This paper describes some test results of the SNS Extraction Kicker power supply prototype. The high repetition rate of 60 pulse per second operation is the challenging part of the design. In the prototype testing, a 3 kA damp current of 700ns pulse-width, 200 nS rise time and 60 Hz repetition rate at 32 kV PFN operation voltage has been demonstrated. An Extraction kicker power supply system design diagram is depicted.
RHIC ABORT KICKER WITH REDUCED COUPLING IMPEDANCE.
Kicker magnets typically represent the most important contributors to the transverse impedance budget of accelerators and storage rings. Methods of reducing the impedance value of the SNS extraction kicker presently under construction and, in view of a future performance upgrade, that of the RHIC abort kicker have been thoroughly studied at this laboratory. In this paper, the investigation of a potential improvement from using ferrite different from the BNL standard CMD5005 is reported. Permeability measurements of several ferrite types have been performed. Measurements on two kicker magnets using CMD5005 and C2050 suggest that the impedance of a magnet without external resistive damping, such as the RHIC abort kicker, would benefit.
RHIC ABORT KICKER WITH REDUCED COUPLING IMPEDANCE.
Kicker magnets typically represent the most important contributors to the transverse impedance budget of accelerators and storage rings. Methods of reducing the impedance value of the SNS extraction kicker presently under construction and, in view of a future performance upgrade, that of the RHIC abort kicker have been thoroughly studied at this laboratory. In this paper, the investigation of a potential improvement from using ferrite different from the BNL standard CMD5005 is reported. Permeability measurements of several ferrite types have been performed. Measurements on two kicker magnets using CMD5005 and C2050 suggest that the impedance of a magnet without external resistive damping, such as the RHIC abort kicker, would benefit.
RHIC ABORT KICKER WITH REDUCED COUPLING IMPEDANCE.
2002-06-02
Kicker magnets typically represent the most important contributors to the transverse impedance budget of accelerators and storage rings. Methods of reducing the impedance value of the SNS extraction kicker presently under construction and, in view of a future performance upgrade, that of the RHIC abort kicker have been thoroughly studied at this laboratory. In this paper, the investigation of a potential improvement from using ferrite different from the BNL standard CMD5005 is reported. Permeability measurements of several ferrite types have been performed. Measurements on two kicker magnets using CMD5005 and C2050 suggest that the impedance of a magnet without external resistive damping, such as the RHIC abort kicker, would benefit.
2005-06-29
The adsorption of methylene blue (MB) onto zirconium phosphate (ZrP) was studied and the adsorption capacity value and isotherms were determined. The adsorption capacity of ZrP was increased after being exposed to gas phase n-butyl amine. The adsorbed MB on ZrP was used as a modifier material in carbon paste electrode (MCPE), which in turn was used in voltammetric investigations and flow injection (FI) amperometric determination of ascorbic acid (AA). A quasi-reversible electrode reaction of adsorbed MB was exhibited. A home made flow-through electrochemical cell with a suitable transparent window for irradiation of the electrode surface was constructed and used for amperometric FI studies. The photoamperometric-FI conditions were optimised as 1.5 mL min{sup -1} flow rate, a 25 cm transmission tubing length, a 100 {mu}L injection volume, and a constant applied potential of +100 mV versus SCE. The calibration curve for AA was linear over the concentration range from 1.0 x 10{sup -6} to 4.0 x 10{sup -5} M. The relative standard deviation of four replicate injections of 3.0 x 10{sup -5} M AA was 1.2%. The results obtained for AA determination in pharmaceutical products are in good agreement with those obtained using the procedure involving the reaction between triiodide and AA.
The new control system of the SPS injection kicker
The SPS accelerator will be used as injector for the LHC and has to be adapted to the LHC requirements. The tight specification on beam blow-up and bunch spacing in the SPS has required an upgrade program of the SPS injection kicker in order to obtain a reduction of the magnetic field ripple to less than 0.5% and of the magnet current rise time to less than 145 ns. In this context, the slow control part has been entirely rebuilt on the basis of off-the-shelf industrial components. A hierarchical architecture based on a SIEMENS S7-400 master programmable logic controller interconnected through PROFIBUS-DP to S7-300 deported and decentralised I/Os has been implemented. Integration of in-house specific G-64 hardware systems inside this industrial environment has been done through a PROFIBUS-DP to G-64 intelligent interface based on an OEM fieldbus mezzanine board on one side and an FPGA implementing the required functionality on the other. Simultaneously, the fast timing system has been completely reshuffled in order to provide the required SPS multi-cycling functionality and a synchronisation of the 16 magnets to 5ns. This modular architecture has been successfully integrated inside the new SPS accelerator control infrastructure and will be duplicated in the future for the control of the different SPS extraction channels.
Full Text Available.BackgroundThe maternal zygotic transition marks the time at which transcription from the zygotic genome is initiated and a subset of maternal RNAs are progressively degraded in the developing embryo. A number of early zygotic genes have been identified in Drosophila melanogaster and comparisons to sequenced mosquito genomes suggest that some of these early zygotic genes such as bottleneck are fast-evolving or subject to turnover in dipteran insects. One objective of this study is to identify early zygotic genes from the yellow fever mosquito Aedes aegypti to study their evolution. We are also interested in obtaining early zygotic promoters that will direct transgene expression in the early embryo as part of a Medea gene drive system.ResultsTwo novel early zygotic kinesin light chain genes we call AaKLC2.1 and AaKLC2.2 were identified by transcriptome sequencing of Aedes aegypti embryos at various time points. These two genes have 98% nucleotide and amino acid identity in their coding regions and show transcription confined to the early zygotic stage according to gene-specific RT-PCR analysis. These AaKLC2 genes have a paralogous gene (AaKLC1) in Ae. aegypti. Phylogenetic inference shows that an ortholog to the AaKLC2 genes is only found in the sequenced genome of Culex quinquefasciatus. In contrast, AaKLC1 gene orthologs are found in all three sequenced mosquito species including Anopheles gambiae. There is only one KLC gene in D. melanogaster and other sequenced holometabolous insects that appears to be similar to AaKLC1. Unlike AaKLC2, AaKLC1 is expressed in all life stages and tissues tested, which is consistent with the expression pattern of the An. gambiae and D. melanogaster KLC genes. Phylogenetic inference also suggests that AaKLC2 genes and their likely C. quinquefasciatus ortholog are fast-evolving genes relative to the highly conserved AaKLC1-like paralogs. Embryonic injection of a luciferase reporter under the control of a 1 kb fragment upstream of the AaKLC2.1 start codon shows promoter activity at least as early as 3 hours in the developing Ae. aegypti embryo. The AaKLC2.1 promoter activity reached ~1600 fold over the negative control at 5 hr after egg deposition.ConclusionsTranscriptome profiling by use of high throughput sequencing technologies has proven to be a valuable method for the identification and discovery of early and transient zygotic genes. The evolutionary investigation of the KLC gene family reveals that duplication is a source for the evolution of new genes that play a role in the dynamic process of early embryonic development. AaKLC2.1 may provide a promoter for early zygotic-specific transgene expression, which is a key component of the Medea gene drive system.
BackgroundThe maternal zygotic transition marks the time at which transcription from the zygotic genome is initiated and a subset of maternal RNAs are progressively degraded in the developing embryo. A number of early zygotic genes have been identified in Drosophila melanogaster and comparisons to sequenced mosquito genomes suggest that some of these early zygotic genes such as bottleneck are fast-evolving or subject to turnover in dipteran insects. One objective of this study is to identify early zygotic genes from the yellow fever mosquito Aedes aegypti to study their evolution. We are also interested in obtaining early zygotic promoters that will direct transgene expression in the early embryo as part of a Medea gene drive system.ResultsTwo novel early zygotic kinesin light chain genes we call AaKLC2.1 and AaKLC2.2 were identified by transcriptome sequencing of Aedes aegypti embryos at various time points. These two genes have 98% nucleotide and amino acid identity in their coding regions and show transcription confined to the early zygotic stage according to gene-specific RT-PCR analysis. These AaKLC2 genes have a paralogous gene (AaKLC1) in Ae. aegypti. Phylogenetic inference shows that an ortholog to the AaKLC2 genes is only found in the sequenced genome of Culex quinquefasciatus. In contrast, AaKLC1 gene orthologs are found in all three sequenced mosquito species including Anopheles gambiae. There is only one KLC gene in D. melanogaster and other sequenced holometabolous insects that appears to be similar to AaKLC1. Unlike AaKLC2, AaKLC1 is expressed in all life stages and tissues tested, which is consistent with the expression pattern of the An. gambiae and D. melanogaster KLC genes. Phylogenetic inference also suggests that AaKLC2 genes and their likely C. quinquefasciatus ortholog are fast-evolving genes relative to the highly conserved AaKLC1-like paralogs. Embryonic injection of a luciferase reporter under the control of a 1 kb fragment upstream of the AaKLC2.1 start codon shows promoter activity at least as early as 3 hours in the developing Ae. aegypti embryo. The AaKLC2.1 promoter activity reached ~1600 fold over the negative control at 5 hr after egg deposition.ConclusionsTranscriptome profiling by use of high throughput sequencing technologies has proven to be a valuable method for the identification and discovery of early and transient zygotic genes. The evolutionary investigation of the KLC gene family reveals that duplication is a source for the evolution of new genes that play a role in the dynamic process of early embryonic development. AaKLC2.1 may provide a promoter for early zygotic-specific transgene expression, which is a key component of the Medea gene drive system.
Latanoprost in the treatment of eyelash alopecia in alopecia areata universalis
2010-01-01
Abstract Objectives The aim of this study was to test the efficacy of latanoprost in eyelash alopecia areata (AA). Design This study is a 2-year prospective, non-blinded, non-randomized, bilateral eyelash alopecia controlled study. Setting The setting of this study was Trichology Unit, Virgen Macarena University Hospital, Seville, Spain. Patients We conducted a survey of 54 subjects with AA universalis treated with the protocol of the Trichology Unit of our Department. Control group comprised 10 subjects who received injections of 0.5 mg/cm2 of triamcinolone acetonide (TAC) in their eyebrows and 1 mg/cm2 of TAC injections in affected scalp. The treatment group included 44 subjects who received the same treatment as the control group in scalp and eyebrows but they also applied a drop of lat...
In vivo radioimmunodetection of amyloid deposits in experimental amyloidosis
1986-01-01
Two rat IgG monoclonal antibodies (MAbs) to mouse AA protein have been used as reagents for an ELISA assay for SAA, for the demonstration of tissue deposits by the immunoperoxidase method, and for the definition of AA polymorphs in solubilized amyloidotic tissue specimens run onto two-dimensional (2D) gels and probed as Western Blots. Both MAbs localize to tissue deposits in vivo when labelled (MAb*) with I125 or I123 and injected into colchicine-pretreated amyloidotic mice, assessed by (a) whole-body autoradiography (WBAR) (b) external photoscanning (c) tissue autoradiography of perfused organs. Serum t 1/2 of MAb in amyloidotic animals was greatly accelerated compared to controls, and sustained concentration of label was found in spleen, liver, and kidney quantitated by organ counts up to 96 h post injection. MAb label copurified with amyloid ...
Anabolic-androgenic steroid effects on sexual receptivity in ovariectomized rats.
Anabolic-androgenic steroid (AAS) compounds are synthetic androgens taken by athletes to increase physical strength and endurance. Recent studies in our laboratory have demonstrated that AAS administration disrupts the estrous cycle of Long-Evans rats. The present experiments examined the effects of six commonly abused AAS compounds on sexual receptivity in ovariectomized rats. Adult female Long-Evans rats received estradiol benzoate (EB; 2.0 micrograms/day s.c.) for 6 consecutive days followed by 15 days of EB concurrent with daily s.c. injections of 7.5 mg/kg of one of the following AAS compounds: 17 alpha-methyltestosterone, methandrostenolone, nandrolone decanoate, stanozolol, oxymetholone, testosterone cypionate, or the oil vehicle. On Day 15, all female rats received progesterone (1.0 mg/rat) 4 h before testing. Tests for sexual receptivity were conducted on Days 3, 6, 14, and 15 of AAS treatment. Although the time course of AAS effects on sexual receptivity varied, some overall effects were clear. For example, 17 alpha-methyltestosterone, methandrostenolone, nandrolone decanoate, and stanozolol interfered with the display of sexual receptivity on Day 14, whereas oxymetholone and testosterone cypionate had no effect. Rats in all groups displayed high levels of sexual receptivity after receiving progesterone on Day 15. Our results show that AAS compounds vary in their degree of inhibition of female sexual behavior in ovariectomized rats.
Purification and biological effects of Araucaria angustifolia (Araucariaceae) seed lectin
This paper describes the purification and characterization of a new N-acetyl-D-glucosamine-specific lectin from Araucaria angustifolia (AaL) seeds (Araucariaceae) and its anti-inflammatory and antibacterial activities. AaL was purified using a combination of affinity chromatography on a chitin column and ion exchange chromatography on Sephacel-DEAE. The pure protein has 8.0 kDa (SDS-PAGE) and specifically agglutinates rabbit erythrocytes, effect that was independent of the presence of divalent cations and was inhibited after incubation with glucose and N-acetyl-D-glucosamine. AaL showed antibacterial activity against Gram-negative and Gram-positive strains, shown by scanning electron microscopy. AaL, intravenously injected into rats, showed anti-inflammatory effect, via carbohydrate site interaction, in the models of paw edema and peritonitis. This lectin can be used as a tool for studying bacterial infections and inflammatory processes.
Purification and biological effects of Araucaria angustifolia (Araucariaceae) seed lectin
2006-01-01
This paper describes the purification and characterization of a new N-acetyl-D-glucosamine-specific lectin from Araucaria angustifolia (AaL) seeds (Araucariaceae) and its anti-inflammatory and antibacterial activities. AaL was purified using a combination of affinity chromatography on a chitin column and ion exchange chromatography on Sephacel-DEAE. The pure protein has 8.0 kDa (SDS-PAGE) and specifically agglutinates rabbit erythrocytes, effect that was independent of the presence of divalent cations and was inhibited after incubation with glucose and N-acetyl-D-glucosamine. AaL showed antibacterial activity against Gram-negative and Gram-positive strains, shown by scanning electron microscopy. AaL, intravenously injected into rats, showed anti-inflammatory effect, via carbohydrate site interaction, in the models of paw edema and peritonitis. ...
2009-01-01
In this study, poly(acriflavine), PAF, a compact thin film, was electropolymerized on the glassy carbon (GC) electrode by cyclic voltammetry for sensing ascorbic acid (AA) and dopamine (DA). When comparing with the literatures, it was found that our GC/PAF electrode offers the second largest peak separation, 255mV, between AA and DA at pH 7 owing to the positive nature of the PAF film. The diffusion coefficient and the intrinsic rate constant of AA were determined to be 1.84x10-6cm2s-1 and 0.0032cms-1, respectively, by the rotating disc electrode (RDE) analysis. The effect of carbon nanotube (CNT) loading was also discussed in the study. For an amperometric detection of AA in a flow injection system at 0.2V (vs. Ag/AgCl/satprimed KCl), the sensitivity, linear range, response time, recovery...
NaV1.6a is required for normal activation of motor circuits normally excited by tactile stimulation
2010-01-01
A screen for zebrafish motor mutants identified two noncomplementing alleles of a recessive mutation that were named non-active (navmi89 and navmi130). nav embryos displayed diminished spontaneous and touch-evoked escape behaviors during the first 3 days of development. Genetic mapping identified the gene encoding NaV1.6a (scn8aa) as a potential candidate for nav. Subsequent cloning of scn8aa from the two alleles of nav uncovered two missense mutations in NaV1.6a that eliminated channel activity when assayed heterologously. Furthermore, the injection of RNA encoding wild-type scn8aa rescued the nav mutant phenotype indicating that scn8aa was the causative gene of nav. In-vivo electrophysiological analysis of the touch-evoked escape circuit indicated that voltage-dependent inward current wa...
Spiral kicker for the beam abort system
A brief study was carried out to determine the feasibility of a special kicker to produce a damped spiral beam at the beam dump for the beam abort system. There appears to be no problem with realizing this concept at a reasonably low cost.
Spiral kicker for the beam abort system
1983-01-01
A brief study was carried out to determine the feasibility of a special kicker to produce a damped spiral beam at the beam dump for the beam abort system. There appears to be no problem with realizing this concept at a reasonably low cost.
Degassing of the AGS extraction magnets with uv light
Two types of degassing sources, a uv lamp and in Infrared (IR) radiant heat lamp, were tested in spare AGS kicker magnets and septum magnets. This paper reports our study of the degassing treatment during pumpdowns of two kicker magnets.
Degassing of the AGS extraction magnets with uv light
Two types of degassing sources, a uv lamp and in Infrared (IR) radiant heat lamp, were tested in spare AGS kicker magnets and septum magnets. This paper reports our study of the degassing treatment during pumpdowns of two kicker magnets.
Degassing of the AGS extraction magnets with uv light
1987-01-01
Two types of degassing sources, a uv lamp and in Infrared (IR) radiant heat lamp, were tested in spare AGS kicker magnets and septum magnets. This paper reports our study of the degassing treatment during pumpdowns of two kicker magnets.
In this paper, the kicker magnet is studied by use of the program POISSON. For using the dc-code POISSON in the ac problem of the kicker magnet, an approximation of the ac effects is made, this simplifying the ac problem into a dc problem. The study of the magnet is taken in two steps: assuming the ..gamma.. of the ferrite material is fixed in the calculation to get a preliminary design of the magnet; using the real B /minus/ H curve of the CMD5005 ferrite material in the calculation to get the final design of the magnet. The stored energy, the excitation curve and the excitation efficiency of the kicker magnet are also discussed. 10 figs., 7 tabs.
1989-01-01
In this paper, the kicker magnet is studied by use of the program POISSON. For using the dc-code POISSON in the ac problem of the kicker magnet, an approximation of the ac effects is made, this simplifying the ac problem into a dc problem. The study of the magnet is taken in two steps: assuming the ..gamma.. of the ferrite material is fixed in the calculation to get a preliminary design of the magnet; using the real B /minus/ H curve of the CMD5005 ferrite material in the calculation to get the final design of the magnet. The stored energy, the excitation curve and the excitation efficiency of the kicker magnet are also discussed. 10 figs., 7 tabs.
1994-10-03
A method is described to increase the yield of Anti-Protons/cycle by about a factor of five, without building new storage rings. In this method, the full circumference of the Main Injector is filled and accelerated. Existing RF cavities are then used to perform ``snap coalescing`` which clumps the charge in azimuth to produce 28 large RF bunches {approximately}5ns long. These are then extracted and targeted in a single 11{mu}sec turn of the Main Injector. The resulting P-bars are injected into six turns of the Debuncher using a resonant kicker which injects every 21st RF bucket The result is that every 3rd RF bucket in the Debuncher is occupied. After an h=30 rotation in the Debuncher, ESME simulations indicate a final momentum spread of {plus_minus}0.25%. This is comparable to the current momentum spread after debunching. It is superior to the momentum spreads of {plus_minus}1.2% and {plus_minus}2% which would be produced by the Compressor Ring and Linear Debuncher.
BEAM TRANSFER LINES FOR THE SPALLATION NEUTRON SOURCE.
2002-04-08
Beam transfer lines for the Spallation Neutron Source (SNS) are designed to have low beam losses for hand on maintenance while satisfying the facility footprint requirements. There are two main beam transfer lines, High Energy Beam Transport (HEBT) line which connect super conducting linac to the accumulator ring and Ring to Target Beam transport (RTBT) which transfers beam from accumulator ring to the target. HEBT line not only transfer the beam from linac to ring but also prepare beam for ring injection, correct the energy jitter from the linac, provide required energy spread for the ring injection, clean the transverse and longitudinal halo particles from the beam, determine the linac beam quality, and provide the protection to the accumulator ring. RTBT line transport the beam from ring to target while fulfilling the target requirements of beam size, maximum current density, beam moment on the target in case of ring extraction kicker failure. and protect the target from the ring fault conditions.
150 MeV fixed field alternating gradient (FFAG) accelerator
150 MeV FFAG accelerator is prototype for practical use. Fundamental development of FFAG, research of FFAG accelerator and its application for therapy are investigated. 150 MeV ring consists of 12 sector magnets. The distribution of magnetic field of 12 sector magnets is almost same. 12 MeV proton beam is generated by cyclotron and injection to 150 MeV FFAG. The injection system consists of 2 bump magnets, kicker magnet and septum electrode. RF accelerating cavity system using high-permeability magnetic substance with high magnetic permeability accelerates proton beam to 150 MeV, then the first operation aims at 250 Hz. Return Yoke Free magnet was developed for adjustment. 150 MeV FFAG magnet is constructed and 12 MeV proton beam acceleration is conformed. The final state of 150 MeV FFAG magnet is explained by calculation results. On cancer therapy by proton beam, the three dimensions spot scan method is proposed. (S.Y.)
Impedance of a slotted-pipe kicker
1996-08-01
This paper introduces the principle of a new slotted kicker simply, which is made by using vacuum pipe itself with proper slits as current conductors, and then, presents a rough estimation of its longitudinal and transverse impedance, respectively. Calculation shows that its impedance is reduced significantly compared to our present air-coil kicker. (author)
A flow injection analysis method (FIA), has been developed for the determination of cyanide, thiosulfate and ammonia by atomic absorption spectrometry (AAS). Aqueous solution of the analyte was injected into an on-line column containing glass beads and packed with silver chloride and deionized water was used as the carrier. The analyte dissolves the silver chloride and the dissolved silver complex is introduced to the nebulizer of the AAS. This method has proved to be sensitive, simple and precise. Detection limits of 1.0 {times} 10{sup {minus}7} M, 5.0 {times} 10{sup {minus}7}M and 5.0 {times} 10{sup {minus}6}M were obtained for thiosulfate, cyanide and ammonia, respectively. The precision of the technique was 2.0%, 2.4% and 1.4% in case of thiosulfate, cyanide and ammonia, respectively. The effects of flow rate and sample volume on the FIA/AAS signals are presented.
1981-05-01
Perfusion effluent from isolated rat and hamster lungs caused a relaxation of superfused strip of bovine coronary artery (BCA). This relaxation was abolished by pulmonary infusion of indomethacin. Pre-exposure of rats and hamsters to cigarette smoke during half an hour before the lung perfusion did not change the degree of this initial relaxation of BCA. Injection of 10 micrograms of sodium arachidonate (AA) into the pulmonary circulation of isolated hamster lungs caused a contraction of BCA, which was not changed by cigarette smoke pre-exposure. When AA (10 micrograms) was injected into the pulmonary circulation of isolated hamster lungs during cigarette smoke ventilation the contractions of superfused BCA and rat stomach strip (RSS) were not significantly different from those during the preceding and following air ventilation. In experiments with isolated rat lungs the initial relaxation of superfused BCA was accompanied by a contraction of superfused RSS. AA injection (10 micrograms) into rat lungs caused a further relaxation of BCA and contraction of RSS, which were abolished by pulmonary infusion of indomethacin. Cigarette smoke ventilation of isolated rat lungs caused a relaxation of superfused BCA, which was not abolished by indomethacin. During cigarette smoke ventilation injection of AA (10 micrograms) into the pulmonary circulation of rat lungs caused a relaxation of BCA and a contraction of RSS. The present study indicates that neither cigarette smoke ventilation nor pre-exposure to cigarette smoke has a drastic effect on the metabolism of arachidonic acid to myotropic compounds in isolated hamster and rat lungs.
1995-03-27
The invention deals with an method for improving the recovery from petroleum reservoirs by the use of microorganisms. According to the invention, there is to be injected a suspension of a biological clean breed of the Bacillus licheniformis or spores thereof in order to tighten selectively the relative strong penetrating zones of a reservoir. 2 figs.
2007-01-01
An automated method is described for the determination of zinc in human saliva by electrothermal atomic absorption spectrometry (ET AAS) after on-line dilution of samples with a significant reduction of sample consumption per analysis (1) which allowed the introduction of 10 muL of either solution in the diluent stream. To avoid unnecessary waste of samples, the ...
Simulations of Full Impact of the LHC Beam With a Solid Graphite Target
The Large Hadron Collider (LHC) will operate with 7~TeV/c protons with a luminosity of 10$^{34}$ cm$^{-2}$s$^{-1}$. This requires two beams, each with 2808 bunches. The nominal intensity per bunch is 1.15$\\;\\times\\;$10$^{11}$ protons and the total energy stored in each beam is 362 MJ. In previous papers, the mechanisms causing equipment damage in case of a failure of the machine protection system was discussed, assuming that the entire beam is deflected onto a copper target. Another failure scenario is the deflection of beam, or part of it, into carbon material. Carbon collimators and beam absorbers are installed in many locations around the LHC close to the beam, since carbon is the material that is most suitable to absorb the beam energy without being damaged. In case of a failure, it is very likely that such absorbers are hit first, for example, when the beam is accidentally deflected. Some type of failures need to be anticipated, such as accidental firing of injection and extraction kicker magnets leading to a wrong deflection of a few bunches. Protection of LHC equipment relies on the capture of wrongly deflected bunches with beam absorbers that are positioned close to the beam. For maximum robustness, the absorbers jaws are made out of carbon materials. It has been demonstrated experimentally and theoretically that carbon survives the impact of a few bunches expected for such failures. However, beam absorbers are not designed for major failures in the protection system, such as the beam dump kicker deflecting the entire beam by a wrong angle.Since beam absorbers are closest to the beam, it is likely that they are hit first in any case of accidental beam loss. In the present paper we present numerical simulations using carbon as target material in order to estimate the damage caused to carbon absorbers in case of major beam impact.
Simulation study of electron cloud build up in the SPS MKD kickers
During the 2008 run, an unusual behavior characterizing pressure and temperature increase in some of the dump kickers of the SPS was noticed. In particular, it was observed that 1) the MKDV2 kicker would exhibit maximum heating with 75 ns spaced LHC beams and 2) the pressure rise was specially critical in MKDV1 in presence of 50 ns spaced LHC beams [1]. While the anomalous heating of MKDV2 with 75 ns beams could be tentatively explained by the denser beam current spectrum that would more likely hit one of the kicker impedance peaks, the fast pressure rise in MKDV1 with 50 ns spaced beams was ascribed to a surface effect, namely beam induced multipacting leading to electron cloud formation. This report summarizes a simulation study that was done in order to check whether the electron cloud behavior in the dump kickers could explain the experimental observations.
Phase Advance for Wideband Dampers With Notch Filters
2000-01-01
Consider a simple damper system shown in Figure 1. The phase advance between pickup and kicker is phik. Assume a particle passes through the pickup at time t=0 with a complex betatron amplitude: (rvec A)pu = Ao. When the particle passes through the kicker, the betatron amplitude of the particle will be: (rvec A)kr = Aoejphik. Assume that the damper is timed so that the delay through the electronics matches the time of flight for the particle between pickup to kicker. The difference in phase between the kicker betatron amplitude and the pickup amplitude must be: arg((rvec A)kr)-arg((rvec A)pu) = (2n + 1) pi/2 and phik = (2n+1) pi/2 because the pickup measures the position and the kicker corrects an angle
Electromagnetic simulations of simple models of ferrite loaded kickers
The kickers are major contributors to the CERN SPS beam coupling impedance. As such, they may represent a limitation to increasing the SPS bunch current in the frame of an intensity upgrade of the LHC. In this paper, CST Particle Studio time domain electromagnetic simulations are performed to obtain the longitudinal and transverse impedances/wake potentials of simplified models of ferrite loaded kickers. The simulation results have been successfully compared with some existing analytical expressions. In the transverse plane, the dipolar and quadrupolar contributions to the wake potentials have been estimated from the results of these simulations. For some cases, simulations have also been benchmarked against measurements on PS kickers. It turns out that the large simulated quadrupolar contributions of these kickers could explain both the negative total (dipolar+quadrupolar) horizontal impedance observed in bench measurements and the positive horizontal tune shift measured with the SPS beam.
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