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R. Garoby

JRA3 : High Intensity Proton Pulsed Injectors (HIPPI)
Activity Report for the first quarter of 2004

  1. Work Package 1: Management and Coordination (Leader: R. Garoby, CERN)

The practical means of interaction inside the HIPPI steering committee (Coordinators of Work Packages, HIPPI coordinator and deputy coordinator) have been defined and applied during these first three months of activity. Each WP coordinator sends a short activity report every month. A phone conference takes then place and a summary report is edited afterwards by the JRA coordinator who sends it to the CARE coordinator. Two such reports have been published until now.

A web-site has been created ( which is linked to the CARE site. The pages for each work package will in the future be used to communicate information about results and ongoing work to all interested people inside and outside CARE. Two job openings are already advertised.
Names for the members of the External Scientific Advisory Committee (ESAC) have been selected by the HIPPI steering committee. All people contacted have immediately accepted their nomination and agreed with the dates of the first HIPPI meeting (October 4-6). The final list is:

  • A. Pisent (INFN, Legnaro – Italy)

  • J. Stovall (SNS, Oak Ridge – USA)

  • Y. Yamazaki (J-PARC, Tokai – Japan).

One workshop has been planned by each technical work package. The dates and places have been defined. Moreover, the decision has been taken to hold a 2.5 days long HIPPI meeting, one month before the CARE yearly meeting. This way, a global summary about HIPPI can be prepared and the report from the ESAC can be available at the CARE meeting. In 2004 the HIPPI annual meeting will take place at the GSI laboratory (Darmstadt – Germany), from October 4 in the morning till October 6 at noon.

The work in HIPPI is tightly related to the collaboration between CEA-IN2P3 and CERN about the construction of the IPHI RFQ that will equip the 3 MeV test place at CERN and be used for beam studies in 2007 and 2008. Moreover, the recent positive decision by the International Science and Technology Center (ISTC-Moscow) to support the realization of prototypes of normal conducting accelerating structures in Russia will properly complement the effort in HIPPI. The precise objectives of the WP2 will be reviewed in consequence during the workshop in Grenoble (May 4-5) and the goals and plans will be adapted to optimize synergy.
The schedule shown in Table 1 summarizes the most important events relevant for our community.
Twelve publications have already been announced that will refer to the work taking place inside HIPPI [1-12].
However, the organization inside the participant laboratories has not progressed sufficiently for a proper accounting to be presented in this report of the costs that should have been financed by the E.U. money.

Table 1: Events relevant for HIPPI during the year 2004



























CSC meetings


23 Paris




24 Warsaw







Workshop WP2





3 - 4 Grenoble








Workshop WP3






6 - 7 Saclay







Workshop WP4





10 - 11 CERN








Workshop WP5






4 Darmstadt







Joint workshop with BENE "Physics with a multi-MW proton source"





25 - 27 CERN








HIPPI yearly meeting










4 - 6 Darmstadt



CARE yearly meeting











1 - 5 Hamburg


Other collaborations

















26 -27 Saclay








??? CERN




8 - 10 CERN 29/03 -2/04 Moscow


13 - 14 CERN








Other conferences & workshops




















5 - 9 Lucerne














16 - 20 Lubeck















18 - 22 Bensheim



  1. Work Package 2: Normal Conducting Accelerating Structures (Leader: J.M. Deconto, LPSC)

The Work Package number 2 has begun its activities in accordance to the planning, although some tasks will only begin after a first workshop to be held in Grenoble (May 4-5).

2.1 Technical progress
The work progress is described below, following the HIPPI planning for the first 18 months.
DTL design and prototyping

To avoid duplications, the start of the DTL activity in HIPPI has deliberately been planned after the foreseen date of decision by the ISTC governing board. As hoped, a positive decision has been taken at the beginning of April in favor of project #2888, within which the Russian team from ITEP (Moscow) and VNIIEF (Sarov) will build a prototype of an Alvarez tank for the 3 to 10 MeV energy range. Permanent magnets will be used for the quadrupoles, with a technology mastered by ITEP.

A workshop is then organized on May 4 & 5 at the LPSC (Grenoble) (April 26 on the official planning) to properly define the work in HIPPI so that it complements the Russian contribution.

Final refinements of the Russian contribution itself will be specified in details on May 13 & 14, during the visit at CERN of Russian scientists from ITEP and VNIIEF. The precise planning and the monitoring scheme will be specified at the same time.

DTL beam dynamics

Theoretical work: a study on the influence of statistical gradient errors on beam halo in high-intensity hadron linacs has been finished and submitted for publication [11]. A new set of tools is being developed that facilitates the linac design process using the IMPACT code. They comprise a system for improved beam matching at lattice transitions and conversion of input files for various codes (so far: IMPACT versus TRACE3D). The set also includes tools to ease the calculation and evaluation of statistical errors with IMPACT.

Practical design work: in a collaboration between CCLRC and CERN, a code comparison for the latest LINAC4 lattice is under way [7] and will be published at the LINAC04 conference together with two papers on the general concept of LINAC4 [8] and the CCDTL cavity design for LINAC4 [10]. Work has started on a 180 MeV H- linac for an upgrade of ISIS. Details will be published at EPAC04 [1].
H-mode DTL

A very compact MEBT between RFQ and DTL has been designed. The KONUS beam dynamics has been used to optimize the DTL front end (first tank, 3-9 MeV). The beam dynamics design of a 3-70 MeV CH-DTL section is undertaken, as required for the new GSI Proton Linac. When this will be finalized, the parameters of the first tank will be used for investigations on a 352 MHz, 1:1 scale cold model. In parallel to these activities, cavity optimisation with respect to the maximum shunt impedance is done. During this year, an industrial manufacturer will be involved in a design and fabrication study, based on the cavity geometry resulting from the beam dynamics calculations and the optimization with the code “Microwave Studio”.

In addition, an (elastic and inelastic) mechanical stress study will be performed on a drift tube and supporting stem sample device. These works are part of a new PhD thesis and will be preceded by theoretical studies performed with simulation tools.
Towards the end of 2004 all efforts should lead to the design of the CH-DTL tank 1 prototype power cavity (scheduled for 06.2006).


The activity is done in collaboration between CERN, LPSC and BINP (Novosibirsk – Russia). The Russian part belongs to the ISTC project #2785, approved in October 2003.

Based on a CERN reference design, LPSC is in charge of the 3D RF calculations and RF detailed design, including power deposition and overall definition of the RF system needed. The Russian team concentrates on the design and realization of a technological model, including the detailed thermal studies, the choice of materials, the definition of the achievable tolerances, the brazing and the test of the model. CERN participates to all design aspects and coordinates the overall activity.
The studies made during the first quarter of 2004 are: the theoretical analysis and behaviour understanding of SCL cavities, the first 3D RF calculations in collaboration with CERN. The objective is to get the general design of a cold prototype, to define the test programme, and to propose innovative tuning procedures. LPSC will also work on the thermal aspect, in close relation with the RF calculation and the Russian team. The prototype, foreseen for 2005, will be used for RF testing, tolerance definition and validation of the cavity tuning procedure.

The construction of a CCDTL pre-prototype is going on at the CERN workshop. Some difficulties in the electron beam welding (porosities due to impurities in the stainless steel) have required a time consuming local re-machining and re-welding. The problems have now been solved and the mechanical part has been completed, however the construction is about 4 months behind schedule. Next steps will be the welding of the copper parts, the vacuum tests and finally the copper plating of the stainless steel parts, where some of the delay could be recuperated, so that the device is expected to be ready for RF testing at the end of September (instead of June in the initial planning). The high-power RF tests have been rescheduled for the 4th quarter of 2004. In parallel with the construction of the pre-prototype, all the ancillary equipment needed for the tests (waveguide connection, support, vacuum seals, cooling circuitry, etc.) has been designed and ordered.

In the frame of ISTC project #2875, the Russian team BINP/VNIITF is building a prototype using a different construction technology, better matched to the capabilities of the Russian workshops. The alignment strategy for a complete module is under study at CERN.


2.2 Use of resources

As mentioned in the section 1, only a limited amount of data is available concerning the resources spent for HIPPI because of the lack of preparation of the accounting in the participating laboratories. Nevertheless, the following information can be given:

  • DTL design and prototyping: nothing spent (work starts in May).

  • DTL beam dynamics: one person is involved now at the Rutherford laboratory (RAL), and one person at CERN (partial time, collaboration with RAL). A position for a post-doc at CERN has been opened, to be filled in the autumn of 2004.

  • HDTL: no expenses so far on consumables, but the major part of the cost is expected towards end 2004 / early 2005, for the cold model and prototype design and construction costs. Personnel cost started in April 2004: 3 new PhD students are working on WP2 (and WP5) and 2 of them are mainly funded within the framework of CARE activities. In total, 17 IAP-FU permanent and temporary staff members are working on WP2, with a full time equivalent ranging from 10 – 100 %.

  • SCL: expenses in 2004 will mainly concern travels (2 kEuros). The largest expenses will be in 2005, as soon as the prototype and the experimental program will be decided. Two permanent staff at LPSC are involved (25% and 30% full time equivalent). A PhD student is expected in October, provided the grant is obtained. A master-degree student has been hired from March to June at LPSC (costless for HIPPI).

  • CCDTL: No money has been asked to the E.U. for this activity. About 30 kEuros have already been spent by CERN in 2004 for the cavity prototype.

A three-year fellowship/associateship is advertised on the CARE web site The candidate will be selected during the CERN fellowship committee of May 25, 2004.

  1. Work Package 3: Supra-conducting accelerating structures (Leader: S. Chel, CEA-Saclay)

The first annual HIPPI-WP3 meeting will be held on June 7-8 in Saclay (CEA).

3.1 Technical progress
Following the HIPPI planning for the first 18 months, work progress is commented below.
Elliptical cavities

- The so-called cavity A (the elliptical cavity Z502 designed by INFN-Milano) has been pre-tuned for field flatness and leak-checked to prepare for the vertical tests. It is now ready for shipment to the CEA in Saclay where the components needed for chemical treatment and High Pressure Rincing are being prepared..

In the next three months, the CEA will re-arrange the supporting system of the cryostat to fit it to the cavity. In a joint action, CEA & INFN will also design and fabricate stiff mechanical pieces to keep constant the cavity length during the cold RF power test.

The milestone of Dec. 2004 for the vertical tests is confirmed.

It is worth noting that the elliptical cavity Z501 (identical to the cavity Z502) has been measured at TJNAF. It reached 14 MV/m at Q=5*109 (low field Q0 > 1010), with only modest and easily conditionable multipacting barriers. However, a large Lorentz force detuning was experienced in the tests (46 Hz/(MV/m)2), because of the weakness of the longitudinal support pieces. Therefore more effective mechanical fixture are being designed for the tests in Saclay, to give a more accurate estimate of the Lorentz force coefficient.

- The design work for the so-called cavity B has not yet started.

- For the RF high power source at 704 MHz, talks have been made with CERN to define compatible specifications and a preliminary quotation has been asked to the Thales Company.
Spoke cavities

- FZJ has already begun the preparation of the test stand for the 700 MHz resonator.

- The 700 MHz spoke resonator (developed by FZJ) to be tested will be available later than foreseen. Because of a major revision urgently needed of the electron beam welding machine by the end of 2003, the welding on the Niobium resonator is still not finished. The machine will be re-commissioned in May 2004, and welding is now planned at the beginning of June. For chemical processing of the resonator, various companies and Research Facilities have been contacted. Efforts are made to recover from the 6 months delay due to the welding process and to perform the characterization of the resonator in time for the evaluation report foreseen in March 2005.

- Though the evaluation of the IN2P3-Orsay 352 MHz 2 gap resonator is scheduled for the 2nd half of this year, is it worth knowing that the cavity was ordered to industry last December and should be delivered in September 2004.

- A first 352 MHZ power coupler of 20 KW (CW) is presently in the design phase by IN2P3-Orsay. The final design report is foreseen for July 2004. Main components, like ceramic window, will be ordered in September-October 2004. The tests of the 352 MHz coupler for the spoke cavities foreseen by IN2P3-Orsay for 2005 will need a power amplifier (10-20 kW). It will be available if expected funding is obtained in 2005.

- The ordering of the Niobium sheets for the 352 MHz multi-gap spoke cavity has started at FZJ. First forming tests concerning the end caps will be done with reactor grade Niobium in the next months. Copper model related design work is in its final phase and the copper model production should start this year. In case of problems (delivery time, budget), FZJ envisages to cancel the production of the copper model. The design report is due on May 2005.

- The conceptual layout of the 352 MHz triple spoke resonator is nearly finished by FZJ, and work now focuses on mechanical design and integration of coupler and tuner. Preliminary calculations for coupling and tuning aspects will be performed in the September 2004-April 2005 period by IN2P3-Orsay. The milestone of May 2005 for the design report is confirmed.
CH resonator

- IAP-FU is studying different possibilities for tuning the frequency of a multi-cell CH structure (RF simulation). As a preliminary result, a sensitivity of 190 kHz/mm has been obtained with a squeezing of the end cells on both side of the cavity. For the next months, more calculations are planned in order to estimate the mechanical constraints of the material. The milestone of June 2005 for the conceptual report is confirmed.

Several cold tests are planned to validate the new measurement system of the Frankfurt cryogenic laboratory (IAP-FU) with different superconducting cavities.


3.2 Use of resources

The manpower used for the work reported in section 3.1 is given in Table 2, together with estimates for the second quarter of 2004.

Table 2: Manpower for WP3

Permanent staff

2004 – 1st quarter

2004 – 2nd quarter (estimate)


persons.month (FTE)

persons.month (FTE)


Engineer: 1.3

Technician: 0.1

Engineer: 2.5

Technician: 1.0


Eng.&Tech.: 1.5

Eng.&Tech.: 1.5





Engineer: 1.0

Engineer: 1.0


Eng.&Tech.: 1.0

Eng.&Tech.: 1.0

Temporary staff

2004 – 1st quarter

2004 – 2nd quarter (estimate)


persons.month (FTE)

persons.month (FTE)
















* The information provided by IAP-FU does not quantify the persons.month participating to the activity:

Permanent scientific staff: U. Ratzinger, H. Klein, H. Deitinghoff, R. Tiede

Temporary scientific staff: H. Podlech, H. Liebermann, A. Sauer, G. Clemente, K. Dermati, S. Minaev

Technical staff: D. Bänsch, I. Müller, J. Jaitner, G. Hausen

The following comments are made about the foreseen future expenses:
- INFN: the first priority in the near term future is to use the manpower funds for a mechanical engineer, in order to start the tuner activities in due time (07/04). In the first financial reporting period (M1-M12), expenses will mostly concern manpower and travel (for the Saclay tests), with a limited amount of consumables related to in-house activities.

- CEA: the call for tender for the realisation of the pieces needed for the cavity A (preparation and test) has just been issued. A computation code (necessary for the development of the cavity B and coupler) has been ordered, which will be charged to the CARE-HIPPI account when the proper accounting will be in place in the CEA. Technical specifications and costs of various components needed for the development of the high power test stand (klystron, high-voltage source, RF loads, ...) are being collected. After this preliminary phase, the RF power loads and the klystron tube are expected to be ordered before the end of the year.

  1. Work Package 4: Chopping (Leader: A. Lombardi, CERN)

The first annual HIPPI-WP4 meeting will be held on May 10-11 at CERN.

4.1 Technical progress

Chopper structure A (CERN)

The technical drawings of the chopper structure have been completed (including integration in the quadrupole), the deflecting structure and the ceramics are ready, as well as the plates for one chopper. The ancillary system (feed through,…) and the tank have been on hold for a few months because of overload in the CERN workshop. Work has now resumed and should continue steadily.

The pre-prototype (i.e. the chopper structure without the quadrupole) should be ready for testing by the end of the summer.

Tests of the driver amplifier have started and 400 V with less than 3 nsec rise/fall time have been obtained on a resistive load (to be compared to the target value of 500 V with a 2 nsec rise/fall time).

Dump design and construction

The mechanical design and the radiological study of the dump is finished [12]. An internal coating is necessary to minimize activation by the lost beam. Irradiation tests are planned on May 5, using the Tandem accelerator at the IPN-Orsay, to determine the material to be used for coating. The planning of construction of the dump is confirmed.

Chopper line design and construction

Mechanical drawings of the beam line are completed [13]. All the elements are defined and/or in house. Drawings for the supports are still missing.

Chopper structure B (CCLRC)

a) Distributed slow - wave electrode design (DC to 500 MHz transmission line structures).

One planar, and two helical structures have been modeled using the CST Microwave Studio code. Bench testing of modules that are common to these structures, is planned. A differential time domain reflectometer has been purchased for this purpose. It is hoped that this process will verify the accuracy of the high frequency design code, and, thereby, streamline the final design process. Again, mechanical rigidity, cooling, vacuum, high voltage, special parts, all place constraints on the design. Preliminary 3D mechanical layouts are being developed to address these complex and interactive design issues.

b) Lumped element slow - wave electrode design (DC to 30 MHz structures).

These water-cooled electrode structures also function as beam dumps. Inductance, capacitance, cooling, and vacuum issues have to be carefully controlled. Very high transient surface temperature gradients are expected, and this will impact on the selection of a suitable electrode material. Secondary electron emission could be an issue.

c) Fast transition time, short duration, pulse generator.

Positive and negative polarity pulse generators with sub ~2 ns transition times, ~10 ns pulse duration, ~2.4 MHz burst frequency, and 50 Hz burst repetition frequency, are being developed. The preliminary design will deliver a positive and negative pulse with an amplitude of ~ 1.4 kV to two 50 Ohm loads. This system, together with prototype distributed slow wave structures, and high power terminations, will form a development test bed for the fast chopper beam line component.

d) Slower transition time, long duration, pulse generator.

Positive and negative polarity pulse generators with sub ~15 ns transition times, ~200 ns to infinite pulse duration, ~1.2 MHz burst frequency, and 50 Hz burst repetition frequency, are being developed. The preliminary design will deliver a positive and a negative pulse with an amplitude of ~6.0 kV to two ~40 pF / ~60 nH loads. This system will form a test bed for the slow chopper beam line component.

e) Chopper beam line design.

The beam line design of a 'Tandem' chopper system, developed to address the requirements of the ESS, has been refined. Particle tracking using the General Particle Tracer (GPT) code has enabled efficient optimization of beam apertures. A start has been made on the analysis of beam power density distributions on the chopper beam dumps.

A preliminary 3D mechanical layout is being developed to address these complex design issues. The ESS chopper beam line includes a set of 280 MHz single gap bunching cavities. A preliminary design has been developed using the CST Microwave Studio eigen-mode solver. The design is compact, includes embedded quadrupoles, a vacuum pumping port, and cooling channels.

As planned, the pre-prototype design and test should be done by June 2005.


4.2 Use of resources

- CERN: a three-year fellowship/associateship is advertised on the CARE web site The candidate will be selected during the CERN fellowship committee of May 25, 2004.

- RAL: a three-year fellowship will be opened soon, with hiring in October 04

  1. Work Package 5: Beam dynamics (Leader: I. Hofmann, GSI)

The first annual HIPPI-WP5 meeting will be held on June 4 at GSI.

5.1 Technical progress
Code development

The different tasks under this heading are summarized in table 3, with some remarks about their progress. A series of meeting took place at GSI on January 21-23, in the presence of F. Gerigk (CCLRC). Features and performance of the IMPACT code were discussed. F. Gerigk gave a seminar on error modeling in linacs. Moreover, code bench marking was debated in a specific meeting in Frankfurt with a first discussion about the reference accelerator structure to be used.

This subject will be further treated at the occasion of the first WP5 meeting on June 4, where the reference accelerator structure will be defined and comparison will be initiated between space charge solvers.

Table 3: code development tasks




Development of existing and new codes


3D space charge routine development


Comparison of Poisson solver with analytical solution in free space

Code preparation for superconducting linac


Space charge code development started. Being checked against other codes.

Code benchmarking


IMPACT code implemented at GSI. Comparison initiated between IMPACT/PARMILA/DYNAMION

LORASR development


Testing of different concepts of injection into a DTL

Simulation of CERN 3 MeV test stand



Experiment at UNILAC (GSI)

Beam emittance and beam loss will be measured using a specific instrumentation at UNILAC.

Diagnostic and collimation

The design and construction of the “Bunch Shape and Halo Monitor” has actively progressed at CERN. Most components have been ordered and a large fraction is already delivered. Mechanical design of the vacuum chamber is being made in the drawing office. Progress is in agreement with the schedule.


5.2 Resources

- GSI: a guest scientist is working on analytical Poisson solutions at 50 % of his time.

- CERN: the candidate selected for the beam dynamics position of fellowship/associateship described insection 4.2 will be involved part-time to the tasks in WP5.

HIPPI papers at EPAC04
[1] F. Gerigk, “A new 180 MeV H- Linac for upgrades of ISIS”

[2] E. Zaplatin, W. Braeutigam, R. Maier, R. Stassen, R. Tölle (FZJ/IKP, Jülich), M. Pap, M. Skrobucha (FZJ), “Triple-spoke Cavities in FZJ”

[3] N. Vasyukhin, Y. Senichev (FZJ/IKP), “Space Charge Problem in Low Energy Super-conducting Accelerator”
HIPPI papers at LINAC04
[4] H. Podlech, H. Deitinghoff, H. Klein, H. Liebermann, U. Ratzinger, A. Sauer, R. Tiede (IAP-FU), Z. Li

(GSI - Darmstadt; IMP - Lanzhou) “Development of Superconducting and Room Temperature CH Structures”

[5] R. Tiede, H. Podlech, U. Ratzinger (IAP-FU), W. Barth, L. Groening (GSI), Z. Li (IMP - Lanzhou), “KONUS Beam Dynamics Design of a 70 mA, 70 MeV Proton CH-DTL for SIS18 at GSI.”

[6] Z. Li (IMP - Lanzhou), W. Barth, L. Groening (GSI), H. Podlech, U. Ratzinger, R. Tiede (IAP-FU), “Design of the R.T. CH-Cavity and Perspectives for a New GSI Proton Linac”

[7] F. Gerigk (RAL), E. Benedico Mora, A. Lombardi, E. Sargsyan, M. Vretenar (CERN), “Beam Dynamics for a new 160 MeV H- Linac at CERN (Linac4)”

[8] R. Garoby, K. Hanke, A. Lombardi, C. Rossi, M. Vretenar (CERN), F. Gerigk (RAL), “Design of the Linac4, a New Injector for the CERN Booster”

[9] L.Bruno, F.Caspers, R.Garoby, J.Genest, K.Hanke, M.Hori, A.Lombardi, M.Magistris, A.Millich, M.Paoluzzi, C.Rossi, M.Silari, M.Vretenar (CERN), P.-Y.Beauvais (CEA), P.Ausset (CNRS) “The SPL Front End: A 3 MeV H- Test Stand at CERN”

[10] Y. Cuvet, J. Genest, C. Völlinger, M. Vretenar (CERN), F. Gerigk (RAL), “Development of a 352 MHz Cell-Coupled Drift Tube Linac Prototype”
Other HIPPI publications
[11] F. Gerigk, "Beam halo in high-intensity hadron accelerators caused by statistical gradient errors", to be published in PRSTAB.
EDMS documents
[12] L. Bruno, M. Magistris, M. Silari, “Conceptual Design and Radiological Issues of a Dump for the 3 MeV Test Facility”, EDMS Id 444103   Ext. Ref. CERN-SC-2004--008-RP-TN

[13] Chopper line drawings: EDMS Id 462302  

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