Operation of INDUS-1, India’s First Synchrotron Radiation Source
PradeepKumar, V.Bhatanagar, A.A.Fakhri, P.Fatnani, A.D.Ghodke, R.K.Gupta, P.R.Hannurkar,P.Kant, M.G.Karmarkar, S.Kotaih, M.Pravin Kumar, G.K.Sahoo, R.S.Saini, A.Sharma, S.K.Shukla,
Gurnam.Singh#, B.Singh, H.C.Soni, D.S.Thakur, D.K.Vats and S.K.Prajapati
Centre for Advanced Technology, Indore-452013, INDIA

ABSTRACTINDUS-1 is a 450 MeV electron storage ring for theproduction of Synchrotron Radiation in Visible Ultra
Violet (VUV) range with a critical wavelength of 61 A°.
The ring was commissioned in June 1999. Since then it
is in regular operation. This Synchrotron Radiation
Source (SRS) facility consists of a 20 MeV injector
microtron, a 450 MeV booster synchrotron and a storage
ring. In this paper operation aspects of INDUS-1 SRS
facility will be presented.

INTRODUCTION
Electromagnetic radiation by bending the path ofelectrons moving at speed close to that of light is called
Synchrotron Radiation. Considering widespread utilityof Synchrotron radiation it was decided to build twoSynchrotron radiation sources at Centre for Advanced
Technology, Indore (India). These sources are INDUS-1,a 450 MeV electron storage ring for production of VUVradiation and INDUS-2, a storage ring of 2.5 GeV for Xrays. In the first phase, the development of Synchrotron
radiation source (SRS), INDUS-1 was taken up.

Figure 1: INDUS-1 Synchrotron Radiation facility atCAT, Indore (India)#Corresponding Author, Email: gurnam@cat.ernet.in

INDUS-1 project involved the development of a 450 MeV
electron storage ring and also an injector system which
supplies electrons to it. The injector system consists of a20 MeV Microtron and a 450 MeV Booster Synchrotron.
The INDUS-1 SRS facility is shown in figure1.
The electrons are generated and accelerated to 20 MeV inthe Microtron. After extracting the beam from theMicrotron, it is injected into the Booster Synchrotron; inwhich the energy of the electrons is increased from 20
MeV to 450 MeV. After acceleration to 450 MeV, theelectrons are extracted from the synchrotron and thentransported to the storage ring INDUS-1. This process ofproduction, acceleration and injection is carried out every
one second till the stored current becomes 100 mA. In
INDUS-1, the electron beam keeps circulating for few
hours emitting synchrotron radiation continuously in thedipole magnets. This ring was successfully commissioned
in June 1999 and since then it has been routinely operated.

OPERATION OF INDUS-1
The operation of INDUS-1 starts at 900 hours in themorning and up to 2300 hours in night everyday in twoshifts. In one shift there are five members for theoperation. The members are trained and well qualified.

The shift operation starts with the operation of injector
Microtron. The microtron consists of a dipole magnet of
1.4 m diameter, which produces a magnetic field of 1.8
Kilo Gauss. The acceleration of electrons occur in amicrowave cavity energized by a 5 MW pulsed klystronat 2856 MHz. A lanthanum hexaboride (LaB6) pin of 3mm diameter mounted on a flat face of the cavity is usedas the electron emitter. The electrons emitted from theemitter are accelerated to 20 MeV in 22 orbits. The
vacuum in the microtron is better than 10-7 Torr.
Microtron gives a 20 MeV electron beam with current of
20 mA in pulses of 1 µs duration at a repetition rate of 1
Hz. The paramerters of microtron are given in Table 1.
Table 1:Parameters of microtron
Energy20 MeV
Pulse current
25 mA
Pulse duration
1 µsRepetition rate
1-2 HzAcceleration frequency 2856 MHz
Energy spread
0.2%
The electron beam from the microtron is transported tothe booster synchrotron through transfer line-1 (TL-1),
which has a length of about 14 m. It has three
quadrupole doublets and one dipole magnet to take careof beam parameters as required for the injection process.
The parameters of Booster synchrotron are given in
Table 2.
Table 2: Parameters of Booster synchrotron
Energy450 MeV
Current
30 mA (11 mA achieved)
Circumference
28.45
Superperiod
6Max. dipole field
1.32 Tesla
Tune point
2.25, 1.22
Momentum Compaction 0.151
Revolution frequency
10.5 MHz
Harmonic number
3
Booster synchrotron consists of six super periods, eachconsisting of a dipole magnet and a pair of focusing anddefocusing quadrupole magnets. The maximum
magnetic field of the dipole is 1.32 T. The circumferenceof synchrotron is 28.44 m. The electrons from microtron
through TL-1 are injected in to the synchrotron byadopting a multi-turn injection scheme. A compensatedbump producing maximum amplitude near the injection
septum is produced using three injection kickers. Afterinjecting the beam the electrons are accelerated to 450
MeV in nearly 200 ms following a linear ramp using theRadio Frequency (RF) cavity operating at 31.619 MHz.
Fields in the dipole, quadrupole and storage ringmagnets are synchronously increased during theacceleration. The harmonic number of the ring is threegiving rise to three circulating bunches in the ring. The
accelerated beam is extracted by deflecting it by a fastkicker magnet having a rise time of 45 ns. As theseparation between two bunches is 30 ns, during theextraction process, one out of three bunches is lost andtwo bunches are extracted. These two bunches are thentransported to INDUS-1 storage ring through transferline-2 (TL-2). The synchrotron operates at 1 Hz till 100mA current is filled in INDUS-1 ring. The vacuum
pressure in the synchrotron is better than 10-6 Torr. The
transfer line-2 (TL-2) is about 25 m length. It has fourquadrupole doublets and two dipole magnets to match thebeam parameter at the injection point in INDUS-1.
The parameters of INDUS-1 are given in Table 3.
Table 3: Parameters of INDUS-1 storage ring
Energy450 MeV
Current
100 mA(200 mA achieved)
Bending field
1.5 T
Operating point
1.69, 1.31
1.5×10-7 m.rad
Beam emittance (εx)(εx)
1.5×10-8 m.rad
0.28 mm
Beam Size at center σx0.07 mm
Of Bending magnet σz
Energy spread
3.85×10-4
Momentum compaction
0.235-1.9,-0.3 (measured -2.6,3.1)
Chromaticities ξx,zHarmonic number2Power loss
0.36 KW (from BM)
The ring shown in figure 2 consists of four super periods,
each having one dipole magnet and two doublets ofquadrupoles. Each super period has a 1.3 m long straightsection. Two such straight sections are used for beam
injection; one section accommodates the septum magnet
and the other, diametrically opposite to it, accommodatesa pulsed kicker magnet. The remaining two straightsections, one is used to accommodate an RF cavity. The
circumference of INDUS-1 ring is 18.96 m.

Figure 2: INDUS-1 ring with initial part of beam lines

The RF frequency of 31.619 MHz provides the electron
beam with the additional energy equivalent to the energy
radiated by the electrons in the form of Synchrotron
radiation. It keeps the electrons moving on a fixed orbit
with a fixed energy. The vacuum pressure in INDUS-1
ring is better than 10-9 Torr.

recorded and written in logbook register available in themain control room.

CONTROL SYSTEMRESULTSThe variation of magnetic field with time during ramp ofbooster synchrotron is shown in figure 3. The timing
system pluses of extraction kicker of booster synchrotron,
injection kicker of INDUS-1, two extracted bunches atthe end of TL-2 and stored bunches are shown in figure
4. . Filling of current in INDUS-1 ring with time isshown in figure 5. Everyday shift operation data are

Figure 3: Ramping of magnetic field & DCCT signal

Figure 4: Timing pluses at the time of current
accumulation in INDUS-1
TRA1: Booster extraction kicker pulse
TRA2: Wall Current Monitor at end of TL-2
TRA3: Injection Kicker in Storage ring
TRA4: Wall Current Monitor showing train of pulses instorage ring section 3
Fas t filling of 100mAin 39 seconds on 28.02.2001

Inje cte d Curre nt (mA)

INDUS-1 main control room area is 17×8 m2 andconsists of ten PCs with Window 98 loaded and display
monitors. The operation of Microtron, Booster
Synchrotron and INDUS-1 ring is controlled remotelyfrom main control room.
The control system is a distributed processor network
comprising personal computers serving as intelligent
workstations and a number of microprocessor based
device controllers dedicated to the task of dataacquisition, monitoring and control. Each devicecontroller has an autonomous capability to control thesubsystem to which it is connected. The control system is
distributed hardware wise over three layers. At thebottom is the front-end instrumentation which
conditions the output from an equipment directly
connected to the machine into standard electrical signals.
The front-end instrumentation is connected upward to
intelligent Supervisory Control and Data Acquisition
System (SCADA). The output from these controllers isconnected to a workstation situated in the main controlroom.
The operation of the control system is divided in to twomajor tasks: (i) informing the operator about variousaspects of the operation of the accelerator. These are thevalues of various parameters such as magnet currents,
vacuum pressures, temperatures, frequency, voltages,currents, power, beam positions, time delays, radiationlevels, status of interlocks, status of pumps, etc.
(ii) Conveying the messages and commands issued by
the operator to the concerned devices.
The hardware of the control system is based on a 16 bit
microprocessor; Motorola 68000 family is chosen as thestandard. The hardware is modular based on VME bus.
The SCADA crate consists of a master processor board
based on the 68000 microprocessor and the necessary
input/output modules. I/O modules handle a variety ofanalog and digital signals.

160140120
1008060
40
2002133.000

2133.250

2133.500

Time (9:33:00Pm to 9:33:50PM)

Figure 5: Filling pattern during injection in INDUS-1

The INDUS-1 operation record (stored current Vs time)
during one day is shown in figure 6.

Table 4: Radiation dose at 100 mA stored currentlocation
Source ofDose (mRem/hr)
radiation
Main Control
Bremsstrahlung 0.01
room
Experimental
Bremsstrahlung 0.02
Station
Neutron flux is negligible.

CONCLUSIONS

Figure 6: One day INDUS-1 operation
Radiation levels
Ionising radiation produced due to interaction ofelectron beam with stainless steel vacuum chamber andresidual gas molecules present in it. Based on radiation
hazards existing in INDUS-1, the entire area is divided
in to three zones:
Zone-1 (normally accessible area < 0.1 mRem/hr)
Zone-2 (restricted entry area < 1 mRem/hr)
Zone-3 (entry prohibited area > 10 mRem/hr)
Dose rate measured near INDUS-1 storage ring with 100
mA stored current is shown in Table 4. Radiation leveloutside the shielding around the storage ring during thestorage is well within the permissible limits.

INDUS-1 storage ring was commissioned in june 1999.
Since then it is regularly operated. Initially beam lifetimeat 100 mA stored current was 20 minutes later on it wasincreased up to 75 minutes by using ion clearing electrodevoltage in the ring. The vacuum mainly determines thebeam lifetime in INDUS-1 ring. The lifetime will improvefurther as the ampere-hour operation increases. The beam
is in use for four beam lines, which are alreadycommissioned.

ACKNOWLEDGEMENTS
We thank WAO-2003 organisers, Dr D.D.Bhawalkar,
Director CAT and Sh. S.Kotaih Project Manager, INDUSII for their support to participate in Workshop on
Accelerator Operation (WAO-2003) at KEK Japan. We
also like to mention the valuable contributions made by
Sh K.K.Thakkar, Sh Haridas and Sh M.Nayak onradiation monitoring near INDUS-1 ring and main
control room area.

REFERENCES[1]G.Singh, V.Bhatnagar, A.A.Fakhri, P.Fatnani,
A.D.Ghodke,R.K.Gupta, P.R.Hannurkar, Pradeep
Kant, M.G.Karmarkar, S.Kotaiah, , M.Pravin Kumar,
Pradeep Kumar, G.K.Sahoo, R.S.Saini, A.Sharma,S.K.Shukla, B.Singh, H.C.Soni, D.S.Thakur andD.K.Vats “Synchrotron Radiation Source INDUS-1”,
Proceedings of the DAE-BRNS Indian Particle
Accelerator Conference-2003 (InPAC-2003) pp 8-11.