ILC Beam Tests in End Station A SLAC EPAC Meeting January 24, 2006 Collimator design, wakefields (T-480) BPM energy spectrometer (T-474) Synch Stripe energy spectrometer.

Transcript ILC Beam Tests in End Station A SLAC EPAC Meeting January 24, 2006 Collimator design, wakefields (T-480) BPM energy spectrometer (T-474) Synch Stripe energy spectrometer.

ILC Beam Tests in End Station A

SLAC EPAC Meeting

January 24, 2006 Collimator design, wakefields (T-480) BPM energy spectrometer (T-474) Synch Stripe energy spectrometer (T-475) IP BPMs/kickers —background studies EMI (electro-magnetic interference) M. Woods, SLAC http://www-project.slac.stanford.edu/ilc/testfac/ESA/esa.html

PAC05 paper/poster

: SLAC-PUB-11180, e-Print Archive: physics/0505171 CCLRC LLNL QMUL U. of Bristol UMass Amherst CERN DESY Lancaster U.

Manchester U.

SLAC TEMF TU Darmstadt UC Berkeley U. of Cambridge U. of Oregon KEK Notre Dame U.

U. of Birmingham UCL SLAC EPAC Meeting, Jan. 2006 1

Beam Instrumentation Tests for the Linear Collider using the SLAC A-Line and End Station A

http://www.slac.stanford.edu/grp/rd/epac/LOI/LOI-2003.2.pdf

LOI presented at EPAC meeting in Fall 2003.

Today will give an update and status report on this. We’ve been pursuing this program as a series of test beam experiments, with funding from i) SLAC ILC group, ii) UK, iii) DOE LCRD funding.

3 test beam experiments have been approved and we’ve just completed a successful 5-day commissioning run earlier this month.

2 more 2-week runs scheduled before end of July 2006. Plan for 2 2-week runs in FY07.

2 M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006

T-480: Collimator Wakefields

Collimators remove beam halo, but excite wakefields.

Goal is to determine optimal collimator material and geometry. These studies address achieving the ILC design luminosity.

PIs:

Peter Tenenbaum (SLAC), Nigel Watson (U. of Birmingham, UK)

Collaborating Institutions

: U. of Birmingham, CCLRC-ASTeC + engineering, CERN, DESY, Manchester U., Lancaster U., SLAC, TEMF TU Slot Side view Beam view  =  /2rad r=1.4mm

1 7 mm 2 3 28mm 208mm 4 M. Woods, SLAC 159mm h=38 mm  168mrad r=1.4mm

 1 =  /2 rad  2 =168mrad r 1 =3.8mm

r 2 =1.4mm

  =298mrad   =168mrad r 1 =3.8mm

r 2 =1.4mm

Collimator wakefield box moved from Sector-2 to ESA.

2 sandwiches, each holding 4 collimators, available.

Collimators being provided by UK groups.

Wakefield kick angle measurements provided by T-474 BPMs.

SLAC EPAC Meeting, Jan. 2006 3

T-474, 475: Energy Spectrometers

Precision energy measurements to 50-200 parts per million are needed for Higgs boson and top quark mass measurements. BPM and synchrotron stripe spectrometers will both be evaluated in a common 4-magnet chicane. These studies address achieving the ILC precision measurement goals.

T-474 PIs:

Mike Hildreth (U. of Notre Dame), David Miller (UC London, UK)

Collaborating Institutions

: U. of Cambridge, Royal Holloway, SLAC, UC Berkeley, UC London, U. of Notre Dame • Initially, will use SLAC Linac BPMs. New electronics based on nanobpm work at KEK, being developed by UC Berkeley.

• New BPMs will be designed at UC London in collaboration with SLAC experts • Will test ILC Linac BPMs being developed by C. Adolphsen and G. Bowden

T-475 PI

: Eric Torrence (U. of Oregon)

Collaborating Institutions

: SLAC, U. of Oregon • prototype quartz fiber detector (8 100-micron fibers + 8 600-micron fibers w/ multi-anode PMT readout) is installed at A-line SLM (synch lite Monitor) location.

M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006 4

ESA Equipment Layout

including a future 4-magnet chicane

18 feet

Jan. 2006 commissioning run

: i) 3WAKE1 (T-480), 3WS1 and 3C2 were installed ii) T-474: new BPM electronics were commissioned with existing BPMs iii) T-475: prototype detector commissioned at A-line SLM location iv) new bunch length diagnostics commissioned with rf detectors at a ceramic gap in ESA

March 2006

: 2 SPEAR girders, 3BPM3-5, 3WS2, 3BPM9-11 will also be installed M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006 5

Beam Parameters at SLAC ESA and ILC Parameter

Repetition Rate Energy Bunch Charge Bunch Length Energy Spread Bunches per train Microbunch spacing

SLAC ESA

10 Hz 28.5 GeV 2.0 x 10 10 300 m m 0.2% 1 (2*) - (20-400ns*)

ILC-500

5 Hz 250 GeV 2.0 x 10 10 300 m m 0.1% 2820 337 ns *possible, using undamped beam M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006 6

IP BPMs/Kickers—background studies

Use “spray” beam with Be Target at end of Linac to generate similar flux density and momenta as collision pair background.

Measure sensitivity to backgrounds, EMI.

Plan to submit test beam proposal ~Feb. 1.

(U. of Oxford, SLAC)

EMI Studies

• Plan to characterize EMI along ESA beamline using antennas and fast scopes • Measure dependence on bunch charge, bunch length • $14K available from US-Japan funds for FY06 (KEK, SLAC) M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006 7

Other Tests being discussed:

1. BPM test stations 2. Bunch length and longitudinal profile measurements

•

electro-optic, Smith-Purcell, coherent transition radiation, other?

•

Initial measurements are using rf detectors at a ceramic gap in a few

•

frequency bands from 10GHz-100GHz 300-micron ILC bunch length is same as LCLS after 1 st bunch compressor- ESA is a good place to commission diagnostics for this 3. Spray beam or fixed target to mimic pairs, beamsstrahlung, disrupted beam

•

for testing synchrotron stripe energy spectrometer, IP BPMs, BEAMCAL 4. IR Mockup?

•

Mimick beamline geometry at IP within ±5 meters in z and ±20 cm radially 5. Single Particles (electrons, photons, pions) 1-25 GeV particles with 1 or less particles/bunch at 10Hz for ILC Detector tests

M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006 8

Accelerator Scheduling Committee

(J. Seeman, Chair)

ESA running in FY06:

T-469: Nov. 16-18, 2005 (using secondary beams from Be target in Linac) ILC T-474, T-475, T-480: i) Commissioning run – January 4-9, 2006 ii) 2 runs, each 2-week duration, between March-July 2006

Commissioning run held Jan. 4-9 was very successful!

~20 people taking shifts (including 4 grad students) from SLAC, UC Berkeley, Notre Dame, U. of Oregon, UC London, Daresbury Lab 9 M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006

Safety Reviews

ESA has now been revalidated for using primary beams. A major consideration was reviewing radiation physics requirements and the ESA PPS (personnel protection system).

Additionally, we worked to satisfy requirements for the following safety committees: i) electrical, ii) radiation physics, iii) earthquaking, iv) hoisting & rigging, v) safety overview committee ISMS: safety training and visitor info provided to ILC users —JHAMs, AHAs, STAs are primary means with additional specific walkthru info.

ESA work activities co-ordinated with facilty manager, Carsten Hast, and use of “work authorization sheets.” M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006 10

Radiation Physics and ESA PPS

The ESA PPS does not meet modern standards for redundancy of sub-system components. Additionally, system components are old and some are past their rated service life.

In 2002, there was an AIP to replace the ESA PPS, but it was not completed following the cancellation of the Real Photon Experiments.

The current system has been reviewed by the PPS group, ADSO and independently by Marc Ross and Keith Jobe as part of the ESA revalidation. The system has no single-point failures and is safe for primary beam operation, subject to detailed PPS certification procedures and equipment inspections. PPS certification takes place prior to each experimental run.

• • The cost estimate provided by Ray Larsen and Patrick Bong (PPS) for replacing the ESA PPS Is $500K. This includes a 50% contingency and would use programmable logic controllers (PLCs).

PLCs are new to SLAC PPS but are planned for LCLS PPS work and future upgrades of other SLAC PPS. Approximately $100-150K of this cost estimate is directly applicable to work needed for LCLS. Interim measures: the radiation safety officer has put in place interim measures to ensure safe operation until the ESA PPS is replaced. We will have another ESA PPS review in June 2006.

Will be requesting to run with the existing PPS thru the end of FY08 (end of PEP-II era). ESA running beyond that would require a new PPS.

M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006 11

ESA Beam Tests in LCLS Era?

• controls issues • low bunch charge w/ LCLS gun specs • pulsed magnets to share LCLS beam M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006 12

ESA Expenditures and Budget in FY05-FY07 by SLAC’s ILC group

M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006 13

January 2006 Commissioning Run

1. Infrastructure: • DAQ (both SCP and experimental —evolution from E-166) • Wire scanner for spotsize, emittance measurements • • simple bunch length diagnostics w/ 3 rf detectors (10, 20 and 100 GHz) Energy spread measurements with A-line synch lite monitor (SLM) • A-line commissioning for single bunch, low emittance beams → full characterization of beam’s 6-dim phase space 2. T-474: BPM Energy spectrometer commissioning - new BPM electronics developed at UC Berkeley using existing rf bpms; SIS waveform digitizers provided by UK 3. T-475: Synch. Stripe energy spectrometer - testing Oregon quartz fiber detector at A-Line SLM location 4. T-480: Collimator Wakefield Measurements, • commissioning ASSET collimator wakefield box; get beam cleanly thru 4mm gap and take beam-based alignment data 14 M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006

January 2006 Commissioning Run

Wire Scanner

Collimator wakefield box M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006 15

January 2006 Commissioning Run

Alcove rf BPMs

(3 sets of bpm processors to analyze data) M. Woods, SLAC

100GHz Bunch Length Detector

16 SLAC EPAC Meeting, Jan. 2006

January 2006 Commissioning Run

Oregon quartz fiber detector at A-line SLM location for T-475 DAQ Control at Counting House

SR photons e beam

17 M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006

LiTrack simulation for achieving ILC parameters in ESA

Bunch charge (1E10) DR bunch length (mm) DR energy spread (%) RTL Voltage (MV) RF phase 2-6 (deg) RF phase 10-20 (deg) Aline R56 (m) Aline T566 (m) 2.0

6.0

0.074

38 +10 -17.5

00.465

2.744

M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006 18

January 2006 Commissioning Run

2-d scan versus Linac injection phase and compressor voltage

M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006 19

117-micron vertical spot

January 2006 Commissioning Run

Energy profile with SLM digitized

(saturates at peak)

Energy profile with SLM digitized

(saturates at peak)

1.2%

E/E

Wire scanner measurement of vertical spotsize.

Nominal setup had low energy tail. Optimizing Linac injection phase and compressor voltage for short bunches eliminates low energy tail and gives high energy tail. M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006 20

January 2006 Commissioning Run

Linac emittance with S28 wires

M. Woods, SLAC Q28 and wire scans for measuring horizontal, vertical emittance in ESA  x  y

~ 31. e-05 ~ 4.0 e-05

• expect ~4x emittance growth in A-line due to synch. radiation and chromatic aberrations • data was taken with wrong magnet config for A-line orbit and dispersion matching ( →increased y-emittance?) • vacuum problem at start of A-line may also increase y-emittance SLAC EPAC Meeting, Jan. 2006 21

January 2006 Commissioning Run

T-474 commissioning results using new bpm processors to downmix signals to 70MHz and digitize with SIS waveform digitizers at 100MHz.

~5-micron bpm resolution achieved so far. Expect <1-micron resolution, so studying contributions from phase noise, angle jitter, fitting procedure … M. Woods, SLAC SLAC EPAC Meeting, Jan. 2006 22