Proton Decay Topical Working Group

13 Sep 2010

Ed Kearns Boston University
Scien&c Impact of Proton Decay
Tests a fundamental, but unexplained conservaAon law: baryon number. Grand Unied Theories make specic predicAons: decay modes, lifeAmes, branching raAos. Probes scales forever inaccessible to accelerators. New force carrying parAcles. Deep connecAons with other elds: cosmology, inaAon, BAU, neutrino mass. ExoAc connecAons with theory: strings, Planck scale, extra dimensions. Even if no signal, limits are very constraining on theory.

Theore&cal Outlook

Numerous and various models exist. LifeAme predicAons are not precise typically uncertain by 2-3 orders of magnitude. There are two favored and benchmark decay modes: e+0 (gauge mediated) and K+ (SUSY D=5) good for water good for LAr There are other modes and processes: +0 (flipped), +K0 (SUSY), + and 0 (high BR but high background), among a total of 27 two-body anAlepton+meson; also n-nbar, invisible modes, dinucleon decay, three-body B-L modes, B+L modes. Some theories suppress or exclude nucleon decay.
Soudan Frejus Kamiokande IMB

p p e+ e+

Super-K I+II+III

0 predictions

minimal SU(5)
minimal SUSY SU(5) flipped SU(5), SO(10), 5D SUSY SU(5)

p p n p

e+ K 0
minimal SUSY SU(5) SUGRA SU(5) SUSY SU(5) with additional U(1) flavor symmetry various SUSY SO(10)

predictions

SUSY SO(10) with G(224) SUSY SO(10) with Unified Higgs

/B (years)

Simple signature: back-to-back reconstruction of EM showers Efficiency ~45% dominated by nuclear absorption of 0 Low background ~0.2 events/100 ktyr Relatively insensitive to PMT density.

Super-Kamiokande I

A. Bueno et al. hep-ph/0701101

Time(ns)

< 952 952- 962 962- 972 972- 982 982- 992 992-1002 1002-1012 1012-1022 1022-1032 1032-1042 1042-1052 1052-1062 1062-1072 1072-1082 1082-1092 >1092

Times (ns)

Key points: WC - efficiency and background estimates nearly identical for SK1 and SK2 LAr - similar efficiency & background as water, but low mass makes it uncompetitive
WC Background Rate Discussion

Total momentum (MeV/c)

Current esAmates (/100 kton yr): 0.21 0.03 0.08

1000 900

NEUT (nuance similar) K2K 1KT Near Detector

e+0 proton decay MC

1000 1200
0.16 0.04 0.05 Tight Cuts on Free Proton
efficiency ~ 17% - BG 0.015 evts/100 kton yr - change over ~10-20 Mton yr

are accompanied by n

- assume proton decay is not
- assume factor of 5 rejection (0.04 evts/100 kt yr) - should be checked and studied - N.B. argument changes sign from BG tag in SN relic analysis!

M. Shiozawa NNN09

Gadolinium - high energy neutrino events
Invariant proton mass (MeV/c
300 kt w.Gd (x5 lower BG)
Nuclear interacAon is negligible Kaon momentum is 340 MeV/c, below Cherenkov threshold essenAally a search for kaon decay at rest

6 MeV gamma tag

Combined efficiency ~14% dominated by detector reconstruction Somewhat sensitive to PMT density. Efficiency for SK2 ~ 80% of efficiency for SK1

6 MeV

gamma tag
Gamma tag channel (16O only) eciency = 7.2 1.6 %, background = 0.16 0.05 events, SK1 = 5.8 1.3 %, background = 0.08 0.03 events, SK2
8 < Ngam < 60 (SK1) 4 < Ngam < 30 (SK2)
no candidates in SK1 either

K+ in LAr

simulated real

Bueno et al.

LAr Studies MicroBooNE Group
K-select (topology) without photon/PMT trigger Entering K0 background from cosmic ray interacAons

LAr Veto

Background is entering K0 with charge exchange from nearby cosmic ray interacAons Assume that an acAve veto can be constructed to achieve a background rate reducAon comparable to simply going to great depth SAll require 1.8 m ducial boundary for self-shielding - 20 kton detector with 17 kton FV will have 14 kton FV for K+ proton decay cosmic ray muon
Expected State of Knowledge
Only one contemporary experiment (Super-K, 22.5 kton) Current exposure (SK 1+2+3) = 0.17 Mton yrs Total SK exposure circa 2018 = 0.4 Mton yrs Serious impact on the science case. Other projects? Hyper-K? Something out of LAGUNA? LAr at Okinoshima? In-ocean ideas like TITAND? Too futurisAc to worry. Expect linle impact from theory. Poten&al game-changer: SUSY at the LHC. Poten&al game-changer: candidate events at Super-K.
Major Detector Related Ques&ons
WC: What is the impact of photocoverage? WC: Impact of Gd on atm. nu background reducAon?
Validate factor of 5, study case for K+ BG. Bener Aming of small tubes may help K+
LAr: What is the impact of shallow depth?
LAr: Is a photon-trigger needed? LAr: Can we generate by our own eort the high eciency and low background esAmates of Bueno paper?
Exposure loss due to C.R. muons Background due to K0 charge exchange (and neutrons?) Validate assumpAons used

The SCRF Proton Driver

A New High Intensity Proton Source (and more!) at Fermilab
Bill Foster SRF2005 July 15, 2005

Outline

The Concept
Fermilab Strategic Context
Proton Driver SRF Linac Design
Ferrite Vector Modulator R&D

Hardware in Progress

G. W. Foster SRF 2005

Fermilab

8 GeV SCRF Proton Driver
New idea incorporating concepts from TESLA, SNS, RIA, TRASCO, APT
Copy SNS, RIA, and JPARC Linac designs up to 1.3 GeV Use TESLA Cryomodules from 1.3 - 8 GeV Direct 8 GeV H- Injection into Fermilab Main Injector
Super-Beams in Fermilab Main Injector
2+ MW Beam power at BOTH 8 GeV and 120 GeV Small linac emittances Small losses in Main Injector Very simple operation of the accelerator complex Minimum (1.5 sec) cycle time (eventually faster) MI Beam Power Independent of Beam Energy (flexible neutrino program)
Fermilabs Existing Proton Source

35 yrs old 35 yrs old

FNAL Accelerator Complex 7 major accelerators !)
Drift Tube LINAC 750 KeV 116 MeV
Cockroft-Walton H- ions (750 KeV)
8 GeV Booster Rapid-Cycling Synchrotron
Proton Source = Linac, Booster, Main Injector

35 yrs old

Q: WHAT IS THE SIGNIFICANCE OF THIS NUMBER ?
A: this is the number of vacuum tubes required to accelerate beams to 8 GeV in Fermilabs current Proton Source.
Advantages of the 8 GeV Linac
Replacing a Rapid-Cycling Synchrotron with a SCRF Injector Linac results in an accelerator complex that is:

Simpler

Many fewer components to design and maintain Simpler Beam Dynamics Lower Beam Losses

Lower Wall Power

5 MW AC Power vs. ~20 MW for RCS

More Flexible

Broader Physics Program (direct uses of 8 GeV linac beam) More Upgrade Potential to >> 2 MW beam power
8 GeV Superconducting Linac
OffAxis AntiProton SY-120 FixedTarget Damping Rings for TESLA @ FNAL With 8 GeV e+ Preacc.
With X-Ray FEL, 8 GeV Neutrino & Spallation Sources, LC and Neutrino Factory
Neutrino SuperBeams X-RAY FEL LAB

neutrino

8 GeV Linac

~ 700m Active Length

1% LC Systems Test

Main Injector @2 MW

Bunching Ring

Neutrinos to Homestake

Short Baseline Detector Array
Neutrino Target & Long-Pulse Spallation Source
Target and Muon Cooling Channel
Recirculating Linac for Neutrino Factory

VLHC at Fermilab

Super Beams in the Main Injector & ILC Test Bed
OffAxis SY-120 FixedTarget

The Baseline Missions:

Neutrino SuperBeams

1.5 % ILC Test B ed

8 GeV SC Linac Proton Driver
A Bridge Program to the Linear Collider
Near Term Physics Program (neutrinos+)
Multiple HEP Destinations & Off-Ramps
A seed project for Industrial Participation
50 cryomodules, 12 RF stations, ~1.5% of LC
Fermilabs Fork in the Road
IF ( ILC 2006 CDR looks affordable) THEN
Push for ILC ~2010 construction start at Fermilab
Proceed with 120 GeV Neutrino Program at >1 MW
Superconducting 8 GeV Proton Driver starting 2008
30-120 GeV and 8 GeV Beams at 2-4 MW
Stepping-Stone to delayed ILC construction start ~2012

Pier Oddones presentation to EPP 2010:
Proton Driver Project Planning Currently Supports a FY2008 Construction Start
The Building Block of the 8 GeV Linac

is the TESLA RF Station:

Understanding the production cost of the TESLA RF station is the most important question in (US) HEP.
1 Klystron 1 Modulator ~ 4 Cryomodules 36 SCRF CAVITIES ~1 GeV of Beam Energy
Proton Driver: 8 RF Stations Linear Collider: 500 RF Stations

PULSED RIA

Front End Linac

325 MHz 0-110 MeV

H- RFQ MEBT RTSR SSR DSR Single Modulator 3 MW JPARC Klystron DSR
Multi-Cavity Fanout at 10 - 50 kW/cavity Phase and Amplitude Control w/ Ferrite Tuners
0.5 MW Initial 8 GeV Linac
11 Klystrons (2 types) 449 Cavities 51 Cryomodules

Modulator Modulator

48 Cavites / Klystron

<1 TESLA LINAC

Elliptical Option
or 325 MHz Spoke Resonators

1300 MHz

0.1-1.2 GeV
10 MW TESLA Multi-Beam Klystrons
=.47 =.47 =.61 =.61 =.61 =.61 =.81 =.81 =.81 =.81 =.81 =.81

8 Cavites / Cryomodule

2 Klystrons 96 Elliptical Cavities 12 Cryomodules

TESLA LINAC 1300 MHz

Modulator
8 Klystrons 288 Cavities in 36 Cryomodules

10 MW TESLA Klystrons

36 Cavites / Klystron
=1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1
Modulator Modulator Modulator
Proton Driver Linac - Technology Flow
Other Labs & Universities

JHF (KEK)

Klystrons Cryogenics Linac Accel. Physics <1 Cavity Design Cavities SNS Production Experience Fast Ferrite Shifters Pulsed Modulators

RIA (ANL) APT (LANL)

SNS (JLAB) RIA (MSU)

FNAL ANL / SNS

TESLA COLLABORATION

RF Distribution

325 MHz RFQ and Klystron

SCRF Spoke Cavities

SNS & DESY
SNS / RIA H R PULSED RIA Beta < 1 _ F SCRF Spoke Elliptical Q Cavity Linac Cavity Linac
TESLA Elliptical Cavity SCRF Linac Beta = MHz 8 GeV 1.3 GeV
New FNAL Proton Source Linear Collider Test Facility PROTON DRIVER Main Injector @2 MW
Beam Transport and Collimation Design
NUMI Beamline & Infrastructure

Neutrino Super-beams

FNAL Proton Plan Upgrades
8 GeV beams: P, n, , , e Technological & HEP Applications

BNL / SNS

Main Parameter Decisions

Main Injector Beam: (1.5 E14, 1.5 sec, 2 MW)
Pulse Parameters: ( 8 mA x 3 msec x 2.5 Hz)

(25 mA x 1 msec x 10 Hz)

Ultimate Upgrade:
Operating Frequency: (1300 MHz / 325 MHz)
Copper to SCRF transition: (15 MeV)
SpokestoElliptical transition: (110 - 400 MeV)
Design Margins on 8 GeV H- Transport
Primary Parameter List (for reference)
8 G eV Initial 0.5 M W {U ltim ate 2M W in B rackets}
Baseline M ission via foil stripping in transfer line Possible w /upgrade of Phase Shifters & Injector 8 G eV beam power available directly from linac
PR IM AR Y PAR AM E TE R S
Linac beam kinetic energy Linac Particle Types
For adiabatic capture with 700ns abort gap.
Excludes possible expansion length sam e as Ferm ilab M ain Injector sam e as Ferm ilab M ain Injector for M I-10 Injection point two 20-degree collim ation arcs Ferm ilab M ain Injector M I cycle tim e varies with energy ~ independent of M I Beam E nergy depends on M I beam energy & flat-top
Linac Stand-Alone Beam pow er Linac Pulse repetition rate Linac m acropulse width Linac current (avg. in m acropulse) Linac current (peak in m acropulse) Linac Beam C hopping factor in macropulse Linac Particles per m acropulse Linac Charge per m acropulse Linac Energy per m acropulse Linac average beam current Linac beam m acropulse duty factor Linac RF duty factor Linac Active Length including Front End Linac Beam -floor distance Linac Depth Below Grade Transfer Line Length to Ring Transfer Line Total Bend Ring circum ference Ring Beam Energy Ring Beam Power on Target Ring C irculating C urrent Ring cycle tim e Ring Protons per Pulse on Target Ring C harge per pulse on target Ring Energy per pulse on target Ring Proton pulse length on target Linac W all Power
8 GeV H - ions Protons E lectrons 0.5 {2.0} M W 2.5 {10} Hz 3.0 {1.0} m s 8.7 {26} m A 9.3 {28} m A 94 % 1.56E+uC 208 kJ 0.07 {0.26} m A 0.75 {1.0} % 1.00 {1.3} % 614 m 0.69 m =27 in. 9 m 972 m 40 deg 3319.4 m 8-120 GeV 2 MW 2.3 A 0.2-1.5 sec 1.50E+14 protons 25 uC 200-3000 kJ 10 us 5.5 {12.5} M W at 8-120 G eV 1 turn, or longer with resonant extraction approx 3 M W Standby + 1M W / H z

Linac Segment Details

(for reference)
Open Technical Choice: 3-spoke or Elliptical Room Temp SRF SRF Spoke Option Elliptical Option
Frequency, MHz Energy Range, MeV Beta geometrical Number of cavities or resonators Number of accelerating gaps / cavity Epeak, MV/m Eacc, MV/m Cavity effective length, cm Synchronous phase, deg (typ.) Length of Segment, m Number of Cryomodules Cavities per Cryomodule Magnetic Focusing Type Coupler Power Initial {Ultimate}, kW Cavities per Klystron Initial {Ultimate} Number of Klystrons Initial {Ultimate}

RFQ 325 0.065-32.1 ~TSR 1-spoke 3-15 15-33 0.08 to 0.18 0.2 TBD 32 2.3 to 3.7 10.to -40 to -30 -30 10.4 12.16 Solenoid Solenoid 40 {54} 9 {26} 72 {36} 1 {2} 2-spoke 325 33-110 0.10.67 36.9 -30 17.14 Solenoid 34 {102}
3-spoke 325 110-400 0.10.67 85.8 -30 to -Quad 80 {238} 42 {14} 1 {3}
Low Medium 110-175 175-400 0.47 0.52 15.2 19.2 32.5 42.2 -30 -25 18.8 38.8 Quad Quad 42 {125} 72 {214} 48 {24} 1 {2}
High 1300 400-1200 0.23.7 74.8 -20 70.8 Quad 133 {398} 48 {24} 1 {3}
TESLA 1300 1200-8000 1.26 103.8 -16 438.8 Quad 220 {660} 36 {12} 8 {24}
Parameter List gives subsystem details for technically feasible baseline
http://tdserver1.fnal.gov/8gevlinacPapers/ParameterList2005/CD0_Parameter_List_Current_Version.pdf

Linac Pulse Parameters

8 GeV Initial 8 GeV H-, e+, or e2 MW 13 MW 1 msec 26 mA 10 Hz 52 MV/m 25 MV/m 614 m H1.56 MW ~15 MW 1 msec 26 mA 60 Hz 35 MV/m 16 MV/m 258 m 8 GeV {Ultimate} 8 GeV SNS (Spallation Neutron Source) 1 GeV TESLA-500 TESLA-800 (w/ FEL) 500 GeV 800 GeV e+, e22.6 MW 97 MW 0.95 msec 9.5 mA 5(10) Hz 46.8 MV/m 23.4 MV/m 22 km e+, e34 MW 150 MW 0.86 msec 12.7 mA 4 Hz 21852 / 70 MV/m 35 MV/m 22 km
Comparison with Other SRF Linacs
Linac Energy Particle Type H-, e+, or eBeam Power 0.5 MW AC Power (incl. warm FE) 5.5 MW Beam Pulse Width 3 msec Beam Current(avg. in pulse) 8.6 mA Pulse Rate 2.5 Hz # Superconducting Cavities 384 # Cryomodules 48 # Klystrons 12 # Cavities per Klystron(typ) 36 Cavity Surface Fields (max) 52 MV/m Accel. Gradient (max) 25 MV/m Linac Active Length 614 m
Two Design Points for 8 GeV Linac
Initial: 0.5 MW Linac Beam Power (BASELINE)
8.3 mA x 3 msec x 2.5 Hz x 8 GeV = 0.5 MW Twelve Klystrons Required
Ultimate: 2 MW Linac Beam Power
25 mA x 1 msec x 10 Hz x 8 GeV = 2.0 MW 33 Klystrons Required
Either Option Supports: 1.5E14 x 0.7 Hz x 120 GeV = 2 MW Beam Power from Fermilab Main Injector
H- RFQ MEBT RTSR SSR DSR Modulator 3 MW JPARC Klystron
2 MW Ultimate 0.5 MW Initial 8 GeV Linac
Klystrons (2 types) 470 Cavities 53 Cryomodules
Modulator Modulator Modulator Modulator Modulator
16 Cavites / Klystron 48 Cavites / Klystron
2 Klystrons Elliptical Cavities 12 Cryomodules
12 Cavites / Cavites 36 Klystron/ Klystron
Modulator Modulator Modulator Modulator Modulator Modulator Modulator Modulator

Initial

Ultimate Upgrade Equipment
Initial 0.5 MW Gallery is nearly empty
One Klystron every 180 feet
Ultimate 2 MW Gallery is comfortable
One Klystron every 60 feet G. W. Foster SRF 2005

ILC Compatible Operating Frequencies
Following the selection of the Cold SCRF Option for the ILC,
We have chosen TESLA/XFEL Compatible Frequencies:

(a gift ! )

1300 MHz Main Linac (= ILC / TESLA / XFEL)
325 MHz (=1300MHz/4) Front-End Linac (= JPARC)
Valuable assets at these frequencies:
SRF Cavities, RF Couplers, Cryomodule Designs, Klystrons,
Front-End Linac Designs, Collaborators (e.g. ILC, Euro-XFEL, JPARC)
In the final analysis, it is much easier these days to develop a new SRF cavity design than to develop a new Klystron.
8 GeV Linac Klystrons 2 Types
Thales THMHz 10 MW Multiple Vendors
Toshiba E3740A 325 MHz 3 MW (17 Delivered for JPARC )
Copper-to-SCRF Transition
We have chosen 15 MeV (RFQ + warm TSRs.)
Much lower than SNS ( ~ 186 MeV)
Allows Single Klystron to drive linac up to 110 MeV
Leverages uses of Fast Phase Shifters to produce many
channels of RF from a single Klystron
Previous Design Study assumed 85 MeV DTL
Conventional Solution, still valid
Modified Commercial Product at 325 MHz
Required 7 Klystrons, $30M + contingency etc.
Spokes-to-Elliptical Transition

(BASELINE)

Preserving two technical options (110-400 MeV):
325 MHz triple-spoke Resonators
1300 MHz Elliptical Cavities
The tradeoffs have been extensively discussed
for the Rare Isotope Accelerator (RIA).
Our Decision Will be based on:

Accelerator Physics

Collaboration

325 MHz 0-350 MeV

H- RFQ MEBT RTSR SSR DSR Modulator 3 MW JPARC Klystrons DSR
325 MHz Spoke Option TSR TSR TSR
or1300 MHz Elliptical Cavities

110 MeV 350 MeV

TSR TSR

0.35-1.2 GeV

TSR =.81 =.81 =.81 =.81 =.81 =.81
H- RFQ MEBT RTSR SSR DSR Modulator 3 MW JPARC Klystron DSR
Elliptical Option Spoke Option
or 325 MHz Elliptical Cavities or1300MHz Spoke Resonators

100 MeV 350 MeV

=.47 =.47 =.61 =.61 =.61 =.61 =.81 =.81 =.81 =.81 =.81 =.81 TSR TSR TSR TSR TSR TSR

325 MHz Spoke Resonators

Ken Shepards Talk
Well Developed Technology for RIA, APT,. Simulations indicate excellent beam dynamics Runs Pool-Boiling at 4.5K Simple Cryosystem R&D Demonstration (SMTF): beam properties with pulsed operation.

325 MHz Front-End Linac

Single Klystron Feeds SCRF Linac to E > 100 MeV
SCRF Spoke Resonator Cryomodules

Charging Supply Modulator Capacitor / Switch / Bouncer 115kV Pulse Transformer 325 MHz Klystron Toshiba E3740A (JPARC)

RFQ Ferrite Tuners

RF Distribution Waveguide

325 MHz RF System

MODULATOR: FNAL/TTF Reconfigurable for 1,2 or 3 msec beam pulse 110 kV 10 kV

Charging Supply 300kW

TOSHIBA E3740A
Single JPARC Klystron 325MHz 3 MW
Pulse Transformer & Oil Tank
IGBT Switch & Bouncer BANK
WR2300 Distribution Waveguide

400kW 20 kW 20 kW 120 kW

RF Couplers
I Q M M M M M M M Q Q Q Q Q Q I I I I I I I Q I Q

I Q M M M

Fast Ferrite I Isolated I/Q Q Modulators M

Cables to Tunnel

HM E B T
Medium Energy Beam Transport Copper Cavities
S S R Cryomodule #1 Single-Spoke Resonators
D S R Cryomodule #2 Double-Spoke Resonators
Radio Frequency Quadrupole
1300 MHz Elliptical Cavites
Beta<1 cavities are frequency scaled from 805 MHz designs for SNS/JLAB and RIA/MSU/JLAB
FNAL/MSU Design collaboration investigating low-loss geometries for 1300 MHz Beta=0.81

1300 MHz Cryomodules

B e ta = 0.2 C ry o m o d u le s C a vitie s

Giorgio Apolinaris Talk

M H z E L L IP T IC A L C A V IT Y C R Y O M O D U L E S : 2 -4 T Y P E S
B e ta = 0.4 C ry o m o d u le s C a vitie s
O P T IO N O F E L L IP T IC A L M E D IU M -B E T A C A V IT E S 110 - 400 M eV
B e ta = 0.6 C ry o m o d u le s C a vitie s

TESLA (TTF3)

B e ta = 1.C ry o m o d s 8 C a vitie s
Ferrite Vector Modulator R&D
Provides fast, flexible drive to individual cavites
of a proton linac, when one is using a
TESLA-style RF fanout. (1 klystron feeds 36 cavities)
Also needed if Linac alternates between e- and P. This R&D was started by SNS but dropped due to lack of time. SNS went to one-klystron-per-cavity which cost them a lot of money ($20M - $60M).
Making this technology work is important to the financial feasibility of the 8 GeV Linac.
G.W.Foster - SCRF Proton Driver

April 7, 2004

Cost Driver: Klystrons per GeV
Spallation Neutron Source

FNAL Linac Upgrade

X-Band (warm) NLC

8 GeV Linac (2 MW)

8 GeV Linac (0.5 MW) TESLA 1.20
80 Klystrons Per GeV Beam Energy
RF Fan-out for 8 GeV Linac

KLYSTRON

35 foot waveguide from gallery to tunnel

DIRECTIONAL COUPLER

1/7 Power Split (8.45 dB) 1/6 Power Split (7.78 dB) 1/5 Power Split (6.99 dB) 1/4 Power Split (6.02 dB) 1/3 Power Split (4.77 dB) 1/2 Power Split (3.01 dB)
1/8 Power Split (9.03 dB)

CIRCULATOR/ ISOLATOR

E-H TUNER

Magic Tee

Ferrite Loaded Stub

CAVITY

Nov 18, 2004
G.W.Foster - Proton Driver

RF Fanout at Each Cavity

KLYSTRON - RF Power Source - Located in Gallery above tunnel - Each Klystron Feeds 8-16 Cavities
DIRECTIONAL COUPLER - Picks of a fixed amount of RF power at each station - Passes remaining power downstream to other cavities CIRCULATOR / ISOLATOR - Passes RF power forward towards cavity - Diverts reflected power to water cooled load
E-H TUNER - Provides Phase and Amplitude Control for Cavities - Biased Ferrite Provides Electronic Control
SUPERCONDUCTING RF CAVITY - Couples RF Power to Beam

FERRITE VECTOR MODULATOR

(1300 MHz Waveguide Version)
MICROWAVE INPUT POWER from Klystron and Circulator
Reflected Power (absorbed by circulator)
ATTENUATED OUTPUT TO CAVITY
ELECTRONIC TUNING WITH BIASED FERRITE
Ferrite Loaded Stub Magic Tee

Bias Coil

FERRITE LOADED SHORTED STUBS CHANGE ELECTRICAL LENGTH DEPENDING ON DC MAGNETIC BIAS.
TWO COILS PROVIDE INDEPENDENT PHASE AND AMPLITUDE CONTROL OF CAVITIES

Advanced RF Distribution

DIRECTIONAL COUPLER (POWER SPLIT)

RF FROM KLYSTRON

COAXIAL FERRITE STUB TUNER AND WAVEGUIDE TRANSITION

CIRCULATOR AND LOAD

MAGIC TEE AND CAVITY RF POWER COUPLER

3 Types of Fast-Ferrite Tuners

Iouri Terechkines Talk

1. Waveguide Style (prototyped in house) 2. Coaxial Style (prototyped in-house) 3. Strip Line Style (commercial procurement via AFT)
Because of this devices importance to the PD, all three are being pursued in parallel.
At present, it appears that all 3 approaches will lead to workable full-spec devices.
Key Specification of Ferrite Tuners
Power Handling 0.6 MW50kW
x4 for full reflected standing wave exceeded by prototypes (after some work!)
Range of adjustment: +/- 45 degrees

Larger is possible

Speed of Response: 1 degree per microsecond
Simulations indicate 3-5x slower might be OK
Insertion Loss: 0.1-0.2 dB
Cooling easy at 600kW peak, 1.5% duty factor Not dominant contributor to RF Distribution Losses
Examples of Phase Shifters
L band (1.2 1.4 GHz) 350 kW peak power Field Range Oe Phase shift - 600 Insertion loss - 0.2 dB
Coaxial Device, Bell Labs 1968
Strip-line-based design, by AFT for ANL and CERN, 1998 ~ 2004
352 MHz 250 kW peak power 25% duty cycle 130 phase shift
SNS Waveguide Phase Shifter R&D
805 MHz 500 kW peak power 8% duty cycle 0.15 dB insertion loss
Waveguide-based device, Yoon Kang (ANL) for SNS ~ 2000
High Power 1300 MHz FVM Test

AMHz Klystron

T = 250 sec

F = 5 Hz

We snuck onto Helens Klystron when she was out of town.
High Power Ferrite Tuner Test
Two methods of phase measurements: 1. 2. Oscilloscope measurements Using available IQ modulator
Available phase range was limited by sparking that develops near the HOM resonance frequencies

SF6 added

Max Power - 2000 kW (requirement: 600 kW)
Useable Phase shift ~ 80 (requirement: ~90 degrees)
Elimination of HOM resonances has increased usable range to ~360 degrees at low power levels.

Coaxial Phase Shifter

Coax design is preferred at 325MHz In-house design tested to 660kW at 1300 MHz Tested at 300 kW at ANL with APS 352MHz Klystron Fast coil and flux return should respond in ~50us
Ran for 1 Hour at 300kW x 3 msec x 2 Hz with 4 Temp Rise C very low losses

MORE INFORMATION

Project site:
http://protondriver.fnal.gov
Physics and Machine CD-0 Documents

Recent Directors Review:

http://protondriver.fnal.gov/PDrev15Mar05.htm

Recent ICFA Workshop:

http://www.niu.edu/clasep/HPSLconf/