BINP - Elettra Sincrotrone Trieste

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BINP

Novosibirsk

Budker Institute of Nuclear Physics, Novosibirsk

The VEPP-4M lab http://v4.inp.nsk.su

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement

V. Smaluk, for the VEPP-4 team

6-th International Workshop on Accelerator Operations

Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement

Contents

http://v4.inp.nsk.su

• The VEPP-4 accelerating-storage complex

• High-energy physics experiments

• Operation time distribution

• Failure analysis

• Working cycle automation

• Performance improvement

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement

The VEPP-4 accelerating-storage complex

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement http://v4.inp.nsk.su

The VEPP-4 accelerating-storage complex

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement http://v4.inp.nsk.su

High-energy physics: t

-lepton mass measurement

Precise measurement of the t

-lepton mass at the producing threshold is the principal high-energy physics experiment at the VEPP-4 accelerating-storage complex.

Exact value of the t

-lepton mass is required to verify the lepton universality principle which is one of the postulates of the Standard Model, the most complete theory describing fundamental properties of matter.

At present, measurement accuracy reached in this experiment is the best in the world.

PDG 2006 1776 .

90

0 .

29

0 .

26

MeV

BES 1996 1776 .

96

0 .

31

0 .

27

MeV

BELLE 2006 1776 .

77

0 .

35

0 .

35

MeV

KEDR 2006 1776 .

80

0 .

25

0 .

23

MeV http://kedr.inp.nsk.su

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement http://v4.inp.nsk.su

High-energy physics: y

(2s) and y

(3770)

Precise measurements of the y family meson masses provide the energy scale in the range around 3 GeV which is a basis for accurate determination of masses for all charmed particles.

M y

(2S)

3686.117

0.012

0.015

MeV

M y

(3770)

3773.5

0.9

0.6

MeV

3 times improved

2 times improved

There are only 5 masses (e, p, n, m

, p

) measured with higher accuracy http://kedr.inp.nsk.su

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement http://v4.inp.nsk.su

Beam energy measurement

Resonant depolarization

– high-precision periodic calibration

Compton back-scattering – routine energy monitoring during HEP experiment runs

 s

 

0

 1

  q

 q

0



E [MeV]

440 .

65



0 s 

1



Measurement accuracy

E

E

10

6

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

E

5

10

5

E

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement http://v4.inp.nsk.su

Synchrotron radiation experiments

VEPP-3 SR channels and stations

0a

– LIGA-technology and X-ray lithography

0b – “Explosion"

2 – Precision diffractometry and anomalous scattering

3

– X-ray fluorescence analysis

4

– High-pressure diffractometry

5a – X-ray microscopy and micro-tomography

5b – Time-resolution diffractometry

5c – Small-angle X-ray scattering

6

– Time-resolution luminescence http://ssrc.inp.nsk.su

7

– SR beam stabilization

8 – EXAFS spectroscopy

10 – Metrology and EXAFS spectroscopy in soft X-ray band

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement http://v4.inp.nsk.su

Distribution of the operation time

2004 - 2006

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement

BINP

Novosibirsk http://v4.inp.nsk.su

Experiment time

2000 - 2006 hours

6000

5000

4000

SR HEP

3000

2000

1000

0

2000 2001 2002 2003 2004 2005 2006

HEP 48 372 906 0 2226 2718 3540

SR 2181 1881 1992 2626 1428 2220 2232

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement

Operation http://v4.inp.nsk.su

Shift supervisor

KEDR detector operator

SR users coordinator

Technician on duty

On-call personnel: injector, magnet power supplies,

RF system, injection/extraction, beam diagnostics, control system, electronics, software.

KEDR on-call personnel

SR users

Shift supervisors:

12 physicists,

4 engineers,

2 post-graduate students

Services: power service, vacuum, cooling water, conditioning, transport, etc.

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement http://v4.inp.nsk.su

Machine control and monitoring

Control room workstations

Injector control

VEPP-4M magnet & RF systems

Injector monitoring

VEPP-3 magnet system

Ethernet

VEPP-4M beam monitoring

VEPP-3

RF system

VEPP-3 beam monitoring

Transport line control

Transport line monitoring

KEDR monitoring

Vacuum, temperature, radiation

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement

On-line status in the www http://v4.inp.nsk.su

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement

BINP

Novosibirsk

• PostgreSQL database

• more than 1500 parameters of beams and accelerators

• 1-second samples are available during last 24 hours

• 30-second samples are stored for 1 year

• older data are available from an archive storage

• a set of typical data request scripts is developed

• GUI

Database

http://v4.inp.nsk.su

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement http://v4.inp.nsk.su

Working cycle in a HEP experiment

• accumulation of positrons in the

VEPP-3 (15-20 minutes),

• acceleration up to the extraction energy (5 minutes),

• bunch-by-bunch extraction and injection into the VEPP-4M,

• magnetic cycle and polarity change of the VEPP-3 and Injector (5 minutes),

• electron accumulation

(1-2 minutes), acceleration and injection into the VEPP-4M.

Total time required to refill beams in the VEPP-4M is 30-40 minutes.

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement

BINP

Novosibirsk http://v4.inp.nsk.su

Working cycle automation

Injector

Luminosity control

Betatron tunes

Betatron coupling

Beam matching at IP VEPP-3

Transport lines

VEPP-4M

KEDR luminosity beam currents beam energies betatron tunes beam sizes beam orbits magnet fields timing temperatures etc.

“Autopilot”

VEPP-4M beam injection control

Injector control e + /e accumulation in the VEPP-3

Acceleration

Beam separation at IP

VEPP-4M injection

VEPP-3 magnet cycle

Polarity change

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement http://v4.inp.nsk.su

Results of working cycle automation

120

100

Average luminosity in HEP shifts

86.6

77.7

104.0

97.6

94.0

102.0

83.1

92.3

57.2

114.7

79.7

95.7

92.2

119.2

84.7

97.4

80 нб -1

60

40

20

0

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement

BINP

Novosibirsk http://v4.inp.nsk.su

Magnet systems,

RF systems, beam diagnostic instruments, beam energy measurement systems, etc.

Working time loss incoming power failure, cooling water overheat or leakage, vacuum deterioration including operator training on-the-run both system and application control computers, CAMAC electronics, low-power circuitry of the magnet power supplies and

RF systems

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

Failure indication: no luminosity, beam loss, alarm, etc

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement http://v4.inp.nsk.su

Failure recovering

Easy

Repair by the shift staff

(replace defective devices)

No Yes

Search fault location

Phone to an expert

Call the expert

Return to operation

Fault analysis

Complex

Repair by the expert

Yes

No

Switch off the machine

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement

BINP

Novosibirsk

Performance improvement:

Temperature monitoring system

One of peculiarities of the HEP experiments realized at the VEPP-4M is the highprecision beam energy evaluation.

To estimate the beam energy between absolute calibrations by the resonance depolarization method, an empirical formula is used.

This formula gives 20 keV accuracy of energy interpolation using the dipole magnetic field and temperature of the magnets, tunnel walls, cooling water, etc.

On-line monitoring of the magnetic field with

10 -6 accuracy is realized by the nuclear magnetic resonance method.

For the precise temperature monitoring, a new system has been developed.

http://v4.inp.nsk.su

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement

Performance improvement:

Temperature monitoring system

Hardware :

High-Precision Digital Thermometers DS1631 with the resolution of 0.0625

o C and absolute accuracy of 0.5

o C in the 0

–70 o C temperature range.

http://v4.inp.nsk.su

32-channel controller developed in BINP: automatic scanning of the temperature sensors every second and data writing into the internal memory; relay interlock function to prevent overheat.

Software :

Control program reads data from the all the controllers and writes it to a PostgreSQL database.

GUI is also developed.

The controller.

1 – temperature sensor board;

2 – sensor inside the protection case.

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement

Performance improvement:

Thermostabilization of the magnets http://v4.inp.nsk.su

Measured diurnal variations of the

VEPP-4M beam energy.

Main factor - temperature drift of the VEPP-4M magnets.

Perturbing factors: ambient temperature, atmospheric humidity, conditions in a cooling tower, etc.

Double-loop water cooling system

High-precision thermal sensors

Computer-controlled valve

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement

Performance improvement:

Thermostabilization of the magnets http://v4.inp.nsk.su

Thermostabilization OFF Thermostabilization ON

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement

Performance improvement:

Thermostabilization of the RF cavities http://v4.inp.nsk.su

Unstable phase oscillation occurs due to parasitic high-order modes of the VEPP-4M RF cavities. This instability is one of the main efficiency decreasing factors, because it reduces luminosity drastically. High-amplitude phase oscillation leads to particle loss and can be dangerous for the KEDR detector.

RF cavity temperature variation results in the cavity deformation and then leads to a shift of working conditions away from the stability regions.

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement http://v4.inp.nsk.su

Performance improvement:

Thermostabilization of the RF cavities

Cooling water temp

Thermostabilization OFF,

D t =2 o C

22

21,5

21

Temperature is measured by thermo-sensors with a sensitivity of 10 mV/ o C.

For each RF cavity, 5 kW flowing water heater is switched on/off by controllable electronic switches.

Temperature analysis and power control is provided by a microcontroller.

20,5

20

19,5

25,08

25,06

25,04

25,02

25

24,98

24,96

24,94

24,92

24,9

19

25,1

0 10000 20000 30000 40000 50000 60000

Time (s)

Stabilized cooling water temp

Thermostabilization ON,

D t =0.5

o C

0 10000 20000 30000

Time (s)

40000 50000 60000

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement http://v4.inp.nsk.su

Luminosity integral 2004 – 2006

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement

Physicist and post-graduate students

The VEPP-4 team

Engineers

A.Aleshaev

A.Bogomyagkov

S.Karnaev

V.Kiselev

E.Kremyanskaya

E.Levichev

O.Meshkov

S.Mishnev

I.Morozov

N.Muchnoi

S.Nikitin

I.Okunev

V.Petrov

P.Piminov

Yu.Pupkov

E.Simonov

S.Sinyatkin

V.Smaluk

G.Tumaikin

D.Shatilov

A.Zhuravlev

O.Anchugov

I.Bannikov

M.Bokov

M.Brovin

D.Burenkov

S.Vasichev

Yu.Glukhovchenko

O.Gordeev

V.Erokhov

A.Zhmaka

V.Neufeld

O.Plotnikova

A.Polyanskiy

V.Sandyrev

V.Svischev

I.Utjupin

M.Fomin

D.Shvedov

http://v4.inp.nsk.su

Laboratory technicians

A.Apanasenko

G.Belyakov

V.Bykov

A.Kolesnikov

G.Kurganov

P.Koshkin

I.Lubyagin

A.Maslov

I.Mishin

A.Petrov

A.Poroshin

I.Romanov

S.Rudakov

P.Svischev

A.Soshilov

L.Stebailo

N.Tur

V.Turaev

A.Chabanov

V.Shvaibovich

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

BINP

Novosibirsk

The VEPP-4M Collider Operation in the Experiment of

Precise Tau-lepton Mass Measurement http://v4.inp.nsk.su

Thank you for your attention

6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007

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