ALPI and PIAVE Status and perspectives Anna Maria Porcellato Lab. Naz. INFN Legnaro (PD) Italy
Istituto Nazionale di Fisica Nucleare Laboratori Nazionali di Legnaro ALPI Complex CN accelerator Tandem XTU High Energy Physics Building
Contents Evolution of ALPI - The resonators: Pb/Cu, full Nb, Nb/Cu QWRs Status of PIAVE, the ALPI Positive Ion Injector - The resonators: full Nb QWRs, RFQs ALPI performance and upgrading
Tandem+ALPI and the PIAVE-Injector Upgraded Under Commissioning SC Booster ALPI Positive Ion Injector PIAVE ECRIS Alice 350kV platform EX. Hall 3 Reliable XTU-Tandem EX. Halls 1 and 2
ALPI Evolution ALPI: Linear Accelerator for Heavy Ions Funded in 1988 (97 Pb/Cu cavities, operating at 3 MV/m) Medium β section completed in 94 (44 QWR, Pb/Cu, 160 MHz) 1 st high β cryostat installed at the end of 1995 (Nb/Cu, 160 MHz); 2 nd and last in 2001 3 low β cryostats on line between 1996 and 1999 (12 QWR, Nb, 80 MHz) First beam on target in May 1994; Since then ALPI is operating according to the PAC schedule.
Tandem+ALPI Complex XTU-tandem: 15 MV routinely available, 30 8 MeV/u for H 127 I; 70% beam-time AVAILABLE ALPI: Linear superconducting QWR accelerator; ~ 40 MV equivalent voltage for 12 C 127 I; 30% b-time DATA Accelerated beams in ALPI (2) 8 p-na on target with A=100 masses available 700 ps (FWHM) bunch length on the exp. target 12 C 6+ @ 240 MeV (20 MeV/u), 82 Se 17+ @ 630 MeV (7.7 MeV/u) TO BE NOTED Completed: Energy Upgrade Programme In progress: Programme for efficient cooling of the first 3 cryostats
7000 6000 5000 4000 3000 2000 1000 0 XTU-ALPI: Beam on Target I 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2002: 5500 2003:5500 time (years) Beam on Target (hours)
Accelerated beams in ALPI (1) Date Ion Cavities β in β out Ε/q/cavity Output Energy Output Energy [MeV/Ch-u/cav.] [MeV] [MeV/u] 21-Feb-00 32 S 9,12+ 25 0.107 0.142 0.435 300 9.4 27-Feb-00 36 S 12+ 29 0.101 0.140 0.449 328 9.1 02-Mar-00 62 Ni 11+ 14 0.088 0.105 0.428 316 5.1 14-Mar-00 48 Ca 9+ 18 0.079 0.097 0.436 206 4.3 14-Nov-00 32 S 9,12+ 31 0.107 0.153 0.477 350 10.9 22-Nov-00 58 Ni 6,15+ 29 0.084 0.111 0.367 330 5.7 30-Nov-00 80 Se 11,17+ 31 0.079 0.112 0.453 470 5.9 04-Feb-01 58 Ni 13+ 13 0.087 0.100 0.395 267 4.6 14-Feb-01 58 Ni 13+ 29 0.087 0.118 0.456 380 6.5 22-Feb-01 83 Se 11,17+ 41 0.079 0.124 0.502 590 7.2 03-Mar-01 83 Se 11,17+ 43 0.079 0.129 0.537 631 7.7 15-Jun-01 36 S 9+ 22 0.093 0.117 0.429 230 6.4 29-Jun-01 74 Se 11,18+ 22 0.085 0.111 0.439 422 5.7 07-Jul-01 8 2S e6,16 32 0.074 0.110 0.487 464 5.6 12-Jul-01 65 Cu 6,15 12 0.080 0.093 0.374 260 4.0 13-Nov-01 56 Fe 6+ 32 0.083 0.120 0.562 380 6.8 05-Nov-01 12 C 6+ 43 0.137 0.207 0.523 240 20.0
Accelerated beams in ALPI (2) Date Ion Cavities β in β out Ε/q/cavity Output Energy [MeV/Ch-u/cav.] [MeV] 20-Feb-02 26-Feb-02 2-May-02 14-Mar-02 24-May-02 1-Jun-02 30-Jun-02 31-Oct-02 8-Nov-02 16-Nov-02 27-Nov-02 1-Dec-02 5-Dec-02 10-Dec-02 14-Dec-02 20-Dec-02 8-Jun-03 4-Jul-03 3-Nov-03 10-Nov-03 12 C 6+ 43 0.134 0.207 0.541 240 16 O 7+ 44 0.124 0.197 0.567 289 48 Ca 9+ 29 0.08 0.112 0.525 280 48 Ca 9+ 18 0.079 0.097 0.616 206 64 Ni 11,16+ 29 0.088 0.113 0.585 500 16 O 7,8+ 30 0.13 0.183 0.520 250 32 S 9,12+ 46 0.099 0.176 0.572 463 32 S 9,12+ 41 0.108 0.176 0.587 463 80 Se 11,18+ 33 0.081 0.127 0.598 600 12 C 6+ 43 0.134 0.207 0.539 240 40 Ca 10+ 15 0.092 0.116 0.605 250 40 Ca 10+ 15 0.092 0.116 0.605 250 16 O 7+ 35 0.124 0.183 0.553 250 104 Ru 12,20+ 29 0.075 0.111 0.566 600 32 S 9+ 15 0.098 0.124 0.643 230 12 C 6+ 43 0.134 0.207 0.542 240 64 Ni +12 14 0.08 0.100 0.663 300 48 Ca 9+ 19 0.08 0.106 0.625 252 16 O 6+ 17 0.08 0.149 0.631 166 80 Se 11,18+ 35 0.077 0.149 0.634 630
Accelerated beams in ALPI (3) Date Ion Cavities β in β out Ε/q/cavity Output Energy [MeV/Ch-u/cav.] [MeV] 19-Feb-04 5-Mar-04 13-Mar-04 16-Mar-04 25-Mar-04 1-Apr-04 13-Apr-04 23-Apr-04 54 Cr +10 22 0.080 0.108 0.615 295 40 Ca +10,14 47 0.104 0.184 0.651 631 54 Cr +11 20 0.080 0.108 0.615 295 58 Ni +11 31 0.077 0.114 0.563 350 36 S +9 12 0.094 0.116 0.704 225 64 Ni +11 35 0.075 0.116 0.602 400 82 Se +12 46 0.068 0.115 0.597 505 90 Zr +13 46 0.067 0.115 0.612 555
ALPI-layout CR12 CR13 CR14 CR15CR16 CR17 CR18 CR19 CR20 B4 E X. H A L L B3 COLD BOX 3 CR10 CR9 CR8 CR7 CR6 CR5 CR4 CR3 B2 β=0.11, 160 MHz,Nb/Cu (Pb/Cu) β=0.056, 80 MHz, full Nb. P I A V E β=0.13 160 MHz Nb/Cu. TANDEM EXPERIMENTAL HALLS 1, 2
2004 ALPI currents on target Ion [pna] on targetlinac transmissioni target/i source 36S9+ 6.56 24.08 0.37 58Ni11+ 0.50 27.50 0.42 82Se12+ 6.67 26.23 0.32 90Zn13+ 3.08 30.08 0.27 64Ni11+ 5.45 29.56 0.40
ALPI medium β Pb/Cu resonators 50 installed resonators from 1992 to 1994 Pb/Cu, 160 MHz Average Ea @7W =2,68 MV/m Four cavities still installed in the bunching cryostats
9 Ea [MV/m] ALPI Mar 1995 Pb/Cu Nb Nb/Cu 6 3 0 CR4 low beta CR5 low beta CR6 low beta CR7 CR8 CR9 CR10 CR12 CR13 CR14 CR15 CR16 CR17 CR18 CR19 CR20 (high beta) Cryostat Performance of ALPI accelerating cavities in 1995; four other cavities are installed in the bunching cryostats
QWR Nb sputtering at Legnaro 1988: a research project on QWR Nb sputtering at LNL starts (Palmieri) 1991: first sputtered prototype; 1993: three prototypes reach 6 MV/m @ 7 W dissipated power 1995: Four high β resonators installed in ALPI (4 MV/m @ 7W); process improvements allows to reach 7 MV/m @ 7W 1998: Four new cavities, still on line, operate at 6 MV/m @ 7W 1998: The substitution of Pb with Nb allows to reach 4 MV/m in a medium β ALPI resonator 2003 Upgrading of ALPI medium β resonators completed.
ALPI status in 1999 Medium and high β sections operational; Low β section installed but not usable; Improvement in medium β cavity performance obtained by replacement of Pb film with Nb; Leaks in the cryogenic and beam line valves. Why not associate cryostat maintenance with cavity upgrading? ALPI medium β upgrading possibility at: - Low cost, without necessity of devoted resources - No interference with ALPI operation Better ALPI reliability Use of sputtering technology developed at LNL
Cryostat maintenance Change of the leaking cryogenic valve (external actuator) Change of the leaking Viton sealing in the cryostat beam line valves, from resonator integral conditioning (changed + shielded through stainless steel rings) Gaskets in the He circuits (changed + fixed by silver plated screws) RF lines (Mechanical adjustments + Cu re-plating) Beam damage around beam ports: in the mylar wrapping of the thermal shield (shielding of aluminated Mylar by tantalum protection) Upgrading of the resonators
The increase in performance by Nb/Cu sputtering Ea at 7 W [MV/m] 8 7 6 5 4 3 Out of frequency Installed Nb/Cu resonators To be repaired Removed Pb/Cu resonators Sep03 Apr 99 Jan 01 Dec 00 Jan 01 Jan 03 May 02 Jul 03 Oct 00 Mar 02 Oct 01 Mar 01 Rf line damaged Feb 98 2 1 0 CR7 CR8 CR9 CR10 CR12 CR13 CR14 CR15 CR16 CR17 CR18 CR19 (high cryostat Beta) CR20 (high Beta) The accelerating fields reached by Nb/Cu resonators at 7 W (blue bars) are compared with the ones obtained by the same resonators when still Pb plated (black bars). Two cavities are not in operation. Black arrows indicate a decrease in performance (June 2003) with respect to previous results
Pb Nb Results (operational) E a (@7 W): from 2.4 (Pb) to 4.4 MV/m (Nb) Despite some limitations in the copper base (not best Cu quality, sharp edges & Sharp holes in high-i regions, hidden volumes in brazed joints) No interference with ALPI operation Same cryostat, control system, rf hardware and software 4.4 MV/m 790 kev/u (@ β=β op ;Φ=0)
Nb/Cu resonator advantages Relatively high accelerating fields High mechanical stability Frequency not affected by changes in the He bath pressure (<O.01 Hz/mbar!) Locked up to 7 MV/m without necessity of fast or soft tuners Very reliable Easy to put into operation No degradation with time after installation
High β section: ALPI sputtered Nb/Cu resonators Q 1.00E+10 1.00E+09 1W 3W 7W 1.00E+08 CR20-1 CR20-2 CR20-3 1.00E+07 CR20-4 0 1 2 3 4 5 6 7 8 9 10 11 12 beam port Ea [MV/m] pick-up coupler ALPI β=0.13, 160 MHz resonator views; The cavity has no brazed joint; beam ports are jointed to resonator by indium gaskets
Low β section Ea [MV/m] 10 8 6 4 2 Bulk Nb resonator perforamance 0 CR04-1 CR04-3 CR05-1 CR05-3 CR06-1 CR06-3 Cavity Ea av May 2003: 6.75 MV/m Nb, double wall, 80 MHz Excellent performance, no degradation along years Installed in between 1995-2000 Their cooling down was difficult, upgrading of cryogenic line necessary and scheduled (spring 2004) Sensitivity to He bath pressure drift: 1Hz/mbar
B3 CR12 CR13 CR14 CR15CR16 CR17 CR18 CR19 CR20 COLD BOX B4 E X. H A L L 3 CR10 CR9 CR8 CR7 CR6 CR5 CR4 CR3 B2 β=0.056, 80 MHz, full Nb β=0.110, 160 MHz,Pb/Cu β=0.11, 160 MHz,Nb/Cu β=0.13 160 MHz Nb/Cu TANDEM ECR EXPERIMENTAL HALLS 1, 2
He transfer to the lower β branch 1. More total P for cooling (30 70 mbar), refrigerator and cryostats valves changed (done in 07/03) Liquid Gas 2. More He Flux 2 4 compressors (160 to 205 g/s) (received 09/03) Main Cold Box 4.5 K 7 K 3. Equalization of hydraulic routes to various cryostats (scheduled in 04-05/04): P ~ K on each cryostat 3. Equalization of hydraulic routes to cryostats (similarly for thermal shield gaseous He)
Some work on the mechanical tuners needed 1997-2000: Installation of the 3 lower-β cryostats 1998: the CR06 cavities, locked on line at up to an energy of ~ 6 MV/m ( 58 Ni shift) - fast f 0 changes: no problem - slow f 0 changes: (He P < 10 mbar/min kept for days) compensated by the slow tuner in f 0 feedback mode (poor reproducibility of tuner mechanics noted). The low-β cavity commissioning was interrupted (cryogenics problems) May 2003: the linac operation team can test all 12 cavities at the same time: a) cavity performancen is very good; b) fast f 0 changes OK; c) mechanical tuners could not compensate for P variations of 10 100 mbar/min (mechanical faults) November 2003 January 2004: systematic tests on all the resonators (chaired by the resonator designer), to fix the slow tuning problems April 2004: Systematic test on PIAVE QWR with the old tuner: the He pressure fluctuations are lower than in ALPI. The cavities can be locked adjusting continuously the frequency by the old tuners while the He pressure changes up to 50 mbar/minute May 2004: Four cavity equipped with new design tuners, backlash free, are installed in ALPI.
1. Fast f 0 changes (acoustic vibrations, 40 200 Hz): the dampers keep the frequency oscillations within a few Hz (no need of fast tuners) - checked in March 2002 2. ALPI cryogenic plant has drifts in He bath pressure: - it was designed for Pb/Cu resonators whose sensitivity to change in bath pressure is < 0.01 Hz/mbar - it has to feed both LHe circuit and the thermal shield circuit operating at 7 bar, thus making regulation difficult 0.23bar Pressure 28/05 drifts 00.23 dalle in 00.23.18 ALPI alle 01.25.45 cryostats 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0 600 1200 1800 2400 3000 3600 Frequency locking: keep the QWRs at 80 MHz ± 2 3 Hz 3. Slow f changes (He-P variations 0 seconds minutes): a slow tuner following the pressure fluctuations is required, the present one worked in PIAVE, where f are lower, but is not enough reliable in ALPI; a new type, based on leverage, is under test in ALPI B2 CR4 CR5 CR6 CR7 CR8 secondi Some mechanical improvement needed
ALPI output energy Tandem injector ALPI output [MeV/u] 30 25 20 15 10 5 0 ALPI Dec 1998 ALPI 2003 (low beta not included) ALPI 2003 (low beta included) 12 C 6+ 28 Si 11+ 40 Ca 14+ 63 Cu 17+ A 0 16 O 7+ 20 32 S 12+ 40 58 Ni 17+ 60 79 Br 18+ 80 90 Zr 19+ 100 127 I 120 21+ 140 Tandem 15 MV; F,F 1998 : 11 Pb/Cu cryostats 2003: 13 Nb/Cu cryostats ALPI output Energy Gain: 45% for 6 C;69% for 127 I Linac Energy Gain: 91% for 6 C;132% for 127 I (low β not included)
TTFn ALPI output energy once added 6 more Cryostats 1.10 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 1 90 Zr 13,17+ Tandem at 15 MV TTFn ALPI output energy [MeV/u] 96 91 86 81 76 71 66 61 56 51 46 41 36 31 26 21 16 11 6 1 16 14 12 10 8 6 4 2 0 ALPI output energy [MeVu] Cavity # TTFn 1.10 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 1 12 C 6+ Tandem at 15 MV TTFn ALPI output energy [MeV/u] 96 91 86 81 76 71 66 61 56 51 46 41 36 31 26 21 16 11 6 1 50 45 40 35 30 25 20 15 10 5 0 ALPI output energy [MeVu] Cavity #
PIAVE Status
Why to switch from a Tandem to a q+ injector? E/A [MeV/u] 30 20 10 0 ALPI Output with the two Injectors Tandem Tandem+ALPI (G-F) (1-10 pna) PIAVE+ALPI (40-200 pna) New Injector 0 50 100 A 150 200 250 MORE CURRENT HEAVIER MASSES MORE BEAM TIME AVAILABLE (TWO INJECTORS)
PIAVE design values for RFQs Reference beam: 238 U 28+ (pre-bunched) from an ECR on a 315 kv platform SRFQ1 SRF2 In Out In out Energy 37.1 351.3 585.4 KeV/u 8.82 83.61 139.33 MeV Beta 0.0089 0.0275 0.0355 Voltage 148.0 148.0 280.0 280.0 kv Length 138.9 74.4 cm N of cells 43 13 m 1.2 2.8 2.7 2.8 a 0.7 0.4 0.8 0.8 cm R 0 0.80 0.80 1.53 1.53 cm φ s 40.0 18.0 12.0 12.0 deg E p,s 24. 25.5 MV/m U 1.8 3.5 J Acceptance (norm) 0.8 mm mrad Output long. emittance 0.7 ns kev/u
PIAVE Injector Layout Two SRFQs ECR + LEBT Eight QWRs to ALPI
q/m 28/238 Energy Range 38 948 kev/m β range 0.0094 0.045 Current 1 eµa T. Emittance 0.5 mmmrad (norm) L. Emittance < 0.7 nskev/u PIAVE the new injector Typical Beams ECRIS Element q I (eµa) 16 O 6+ 10 40 Ar 12+ 1 84 Kr 14+ 0.4 129 Xe 18+ 0.5 63 Cu 11+ 0.5 0.7 107 Ag 17+ 0.7 0.8 SRFQs QWRs In Feb 2003 a small fire due to a short circuit forced to stop ECR commissioning to SC booster New start-up of the ECR Ion Source in March 2004 in the previous conditions
Beam Commissioning from ECRIS to SRFQs Transmission: 89% Buncher t < 500 ps, no transverse steering induced Matching: obtained (as computed) at the SRFQ1 entrance
Two superconducting RFQs in a cryostat SRFQ1 SRFQ2 beam line 1.38 m 0.74 m 37 kev/u (β = 0.0089) 585 kev/u (β = 0.035)
SRFQ2 structure Nb tank, full Nb, RRR 250, 3 mm thick 0.74m Trapezoidal-shaped stems, the vertical ones displaced with respect to horizontal ones Modulated electrodes, rod-type, carved inside Empty, baking cylinders 0.8m Ti Stiffening ribs Ti /Nb end flange
Milestones on SRFQs SRFQ1 SRFQ2 Frequency 80 80 MHz Length 1.41 0.8 m Diameter 0.81 0.81 m Weight 280 170 Kg V_interelectrode 148 280 kv Modulated cells 41 13 E s,p 25.5 25.5 MV/m E s,p /E a 12 12 B s,p 0.025 0.03 T Stored Energy 2.1 3.6 J P diss (set) 10 10 W Q 1x10 8 2x10 8 Performance Q 0 vs E p : both above specs Both installed in the line cryostat Leak check of cryogenic circuit OK Locking conditions Tested both in the test cryostat and on the beam line for relativily short times (hours): Slow f 0 changes and their control Fast f 0 changes and their control
SRFQ1 - SRFQ2: performance achieved SCRFQ1 SCRFQ2 1.E+09 10 W Q 1.E+08 10 W 1.E+07 SRFQ2 SRFQ1 0 5 10 15 20 25 30 35 Peak Surface Field [MV/m]
Frequency shift induced by He bath pressurization F = 39 Hz/mbar for RFQ2 F = 48 Hz/mbar for RFQ1-12 khz -8 y = -0.039x + 0.0971-4 frequency shift [khz] 0 0 50 100 150 200 250 300 P [mbar]
How do we cope with slow drifts? By deforming both tuning plates in frequency feedback mode One for + f, the other for f (no mechanical backlash) Tuners performance Frequency range: 150 300 khz (huge) Sensitivity: 0.5 Hz (good) Speed: ~ 2 3 Hz/s Cryogenic-Plant Specs P=1.2 ±0.05 bar; P/ t < 2 mbar/min 1.33 Hz/s In the test cryostat: Margin: factor 2 f < 1 khz/day, at < 1 2 Hz/s IMPORTANT FOR HE IN REFRIGERATION CYCLE NO PROBLEM!
On line test April 2004 Conditioning: faster than in the test cryostat. The couplers located on the cavity bottom probably helped rf antennas: OK both for Q and movement Cavity Q similar to the ones measured in laboratory for both RFQs (if the dissipative load coming from the fast tuners is taken into account) SRFQ2: locking condition (20 Hz bandwidth) maintained for up to 60 minutes, lost for He pressure changes out specification or sometimes for not optimal tuning operation Fast tuners: increase the locking window from from 20 Hz to 200 Hz (SRFQ2) and 70 Hz (SRFQ1, to be increased). Microphonics at negligible level: unlocking at 80 MHz (master) due only to He pressure drifts. Slow tuners will work together with the fast tuners in the next test.
SRFQ2 locking to the master oscillator (80 MHz) P*10 [mbar], Ti [K], He level*10 [%] 10 9 8 7 6 5 4 3 2 1 0 68 % E acc,n Tuner 2 not properly working 84 % E acc,n 21.4 mb/min 3.6 mb/min 0 60 120 180 240 300 360 Time [min] (84 % E acc,n A/q =7.2 208 Pb 29+ e.g.)
Low-β QWR s for PIAVE PIAVE 80 MHz, β=0.047 QWR 80 MHz, low- β QWR cryostat 1.00E+10 PIAVE bulk Nb QWR's Q at 7W Mechanical damper High gradient No fast tuner required Built and tested Installed and operational 1.00E+09 Q 1.00E+08 1.00E+07 new specifications old specifications 0 1 2 3 4 5 6 7 8 9 10 11 12 Ea (MV/m)
2 ALPI low-β section: Cavities locking to the linac clock to be improved To be cooled efficiently 4. CRYOGENIC SYSTEM UPGRADE 3. LOW BETA CAVITIES UPGRADE 4 3 2. PIAVE 1. ECRIS OPERATION 1
On line tests of PIAVE low-β QWR s Good performance for CrQ1-PIAVE resonators:locked up to 5 MV/m making use of the old type slow tuner controlled by an improved version of the soft tuner program Q values lower than the ones measured in laboratory for CrQ1-PIAVE resonators; two cavities of the cryostat out of frequency; microphonic noise more relevant than in CrQ1- PIAVE resonators. Not negligible power consumption at 4 K due to the rf dissipation in the RF input line in strong overcoupling condition used to make locking possible.cryostat removal from the beam line to fix the problems foreseen soon. The resonators should recover the performance by HPWR
Coming next PIAVE beam test foreseen in October 2004 Final test of all the automatic procedures on the refrigerator, operating with the whole cryogenic load, scheduled in September 2004 Beam injection of a PIAVE beam in ALPI foreseen by the end of the year Improvement of ALPI cryogenic system to allow operation of low β resonators completed by July 2004 Substitution of old tuners with new designed ones in low β resonators in progress.
Present ALPI output energy Tandem injector ALPI output [MeV/u] 30 25 20 15 10 5 0 ALPI Dec 1998 ALPI 2003 (low beta not included) ALPI 2003 (low beta included) 12 C 6+ 28 Si 11+ 40 Ca 14+ 63 Cu 17+ A 0 16 O 7+ 20 32 S 12+ 40 58 Ni 17+ 60 79 Br 18+ 80 90 Zr 19+ 100 127 I 120 21+ 140 Tandem 15 MV; F,F 1998 : 11 Pb/Cu cryostats 2003: 13 Nb/Cu cryostats ALPI
ALPI injected by PIAVE Performance of different ECR sources compared with LNL negative source beam intensity PIAVE-ALPI output energy when fed by typical ECR beams Present ALPI authorization limit Constraints ALPI Completion Performance of ALPI after completion Reachable ALPI Energy stripping the ALPI beam
ECRIS currents, compared to LNL negative source Ion A state of charge [LNL ALICE I [Atomki]1 I [S.nanogan] 2 IKF SERSE I [Argonne ECRIS] I after Tandem Stripping e micro A e micro A e micro A e micro A e micro A e micro A e micro A C 12 5 8.6 25 1.983 N 14 5 29 0.717 N 14 6 1.5 1.457 O 16 5 203 O 16 6 10 81 200 150 540 1.510 O 16 7 4 52 0.548 F 19 3 24 F 19 7 1.294 Ca 40 10 0.935 Ca 40 12 0.079 Ar 40 8 202 200 110 Ar 40 9 100 80 Ar 40 12 1 200 Ar 40 14 0.034 1 2 84 Fe 56 11 2.8 0.784 Fe 56 13 1.4 0.075 Fe 56 15 0.22 0.016 Ni 58 10 8.7 0.416 Ni 58 11 0.775 Ni 58 14 0.2 0.024 Ni 58 16 15 Ni 58 17 61 63 Cu 11 1 63 Cu 14 0.3 Ge 74 16 http://www.lnl.infn.it No isotope separation http://www.phys.jyu.fi/ecris02 http://www.lns.infn.it http:hsbpc1.physik.uni-frankfurt.de http://www.pantechnik.com http://www.atomki.hu M. Cavenago, private communication
ECRIS currents, cont Ion A state of charge [LNL ALICE I [Atomki]1 I [S.nanogan] 2 IKF SERSE I [Argonne ECRIS] e micro A e micro A e micro A e micro A e micro A e micro A Kr 84 11 1 10.3 Kr 84 12 1 8.7 27 Kr 84 14 Kr 84 15 0.5 10 Kr 84 22 0.1 Kr 86 18 137 38.5 Zr 90 17 Ag 107 17 0.8 Sn 120 16 0.675 Sn 120 19 0.24 Xe 132 15 0.9 Xe 132 17 0.6 30 Xe 132 18 0.5 Xe 132 25 10 Xe 132 27 3 78 Xe 132 30 38.5 Ta 181 24 3 Pb 208 25 15 Au 197 26 10 2.5 Au 197 29 2 U 238 28 U 238 31 2 U 238 37 6 http://www.phys.jyu.fi/ecris02 No isotope separation http://www.lns.infn.it http:hsbpc1.physik.uni-frankfurt.de http://www.pantechnik.com http://www.atomki.hu M. Cavenago, private communication
Energy output PIAVE injection, 2004 ALPI MeV/u 30.0 25.0 1 12 C 5+ 16 O 7+ 14 N 6+ 40 Ar 14+ 58 Ni 17+ 84 Kr 18+ 120 Sn 19+ 132 Xe 27+ 181 Ta 24+ 197 Au 29+ 208 Pb 25+ 238 U 31+ 20.0 15.0 High current High energy 10.0 5.0 0.0 12 C 5+ 16 O 6+ 14 N 5+ 40 Ar 8+ 58 Ni 11+ 84 Kr 12+ 120 Sn 16+ 132 Xe 17+ 181 Ta 24+ 197 Au 26+ 208 Pb 25+ 238 U 28+ 0 50 100 150 200 250 A PIAVE: - 2 SRFQs at the design accelerating fields -8 low β resonators at 5 MV/m ALPI - 12 low β resonators operating at 4.4 MV/m - 44 medium β resonators operating at 4.4 MV/m - 8 high β resonators operating at 5.5 MV/m
Present authorization limits For ions from Si to Pb: E < 20 MeV/u I < -30 pna on target For ions from C to Al E< -26 MeV/u I<2 pna on target
Constraints ALPI optics was designed for B*ρ=3.3 Tesla*m An accurate beam transport analysis in ALPI is required The RFQs were designed for 5µA; the spatial charge effect must be evaluated for larger current (negligible at 5µA) Maximum possible A/Q for the PIAVE RFQs is 8.5 RFQ transmission is 45%. At high current the beam losses can produce a not negligible thermal load (0.2W for 1 µa of 238 U).
ALPI completion The original ALPI layout foresaw further 6 high β cryostats. The cryogenic lines, magnets, diagnostic box are installed. Only the cryostats and their equipment (cavities, vacuum, rf controller and amplifier ) are missing. The insertion of a low β cryostat is also possible in the low energy branch (useful in case of very heavy ions). A cryostat is in this case available. It is necessary to verify that the cryogenic system can provide the design power (1.3 kw @ K and 3.5 kw @ 70 K) It is necessary to study in detail the beam optics for the different beams
Upgraded ALPI Energy output PIAVE injection MeV/u 40 35 30 25 20 15 10 5 0 12 C 5+ 16 O 7+ 14 N 6+ 40 Ar 14+ 58 Ni 17+ 84 Kr 18+ 120 Sn 19+ 132 Xe 27+ 181 Ta 24+ 197 Au 29+ 208 Pb 26+ 238 U 31+ 12 C 5+ 16 O 6+ High current High energy High energy (Bro>3.5) 14 N 5+ 40 Ar 8+ 58 Ni 11+ 84 Kr 12+ 120 Sn 16+ 132 Xe 17+ 181 Ta 24+ 197 Au 26+ 208 Pb 25+ 238 U 28+ 0 50 100 A 150 200 250 Upgraded ALPI: ALPI 2004+ 24 high β resonator operating at 5.5MV/m
Increasing the energy by beam stripping The final section of ALPI magnetic lattice can not transport the heavier beams at maximum reachable energy. To decrease the beam rigidity and increase the reachable beam energy it is possible to strip the beam in ALPI. Two options are possible: stripping in the diagnostic box before ALPI U band or stripping in the box after it In the first case you can select better the beam accelerated in the second linac branch, making radioprotection issues less demanding In the latter case it is possible to have instead multicharge acceleration in the second linac branch, increasing in such way ALPI output current The output energy is similar in the two cases so only the first option is analyzed
ALPI-layout CR12 CR13 CR14 CR15CR16 CR17 CR18 CR19 CR20 B4 E X. B3 Stripper position COLD BOX H A L L 3 CR10 CR9 CR8 CR7 CR6 CR5 CR4 CR3 B2 β=0.11, 160 MHz,Nb/Cu (Pb/Cu) β=0.056, 80 MHz, full Nb. P I A V E β=0.13 160 MHz Nb/Cu. TANDEM EXPERIMENTAL HALLS 1, 2
ALPI output energy Beam stripped before the U band MeV/u 30.0 25.0 20.0 ALPI 2004 Upgraded ALPI 15.0 10.0 5.0 0.0 40 Ca 10,16+ 58 Ni 14,24+ 84 Kr 18,29+ 120 Sn 16,31+ 181 Ta 24,49+ 208 Pb 25,53+ 40 Ar 8,16+ 56 Fe 13,22+ 74 Ge 13,28+ 90 Zr 17,32+ 132 Xe 17,39+ 197 Au 29,52+ 238 U 28,57+ 0 50 100 A 150 200 250 Upgraded ALPI: ALPI 2004+ 24 high β resonator operating at 5.5MV/m