BINP
Novosibirsk
Budker Institute of Nuclear Physics, Novosibirsk
The VEPP-4M lab http://v4.inp.nsk.su
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
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
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
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
6-th International Workshop on Accelerator Operations, Trieste, 24-28 September 2007